Home

Service Manual VM700T Video Measurement Set 070-9630-04

1. R555 922 1923 sain a Filter Switch board Al gt NTSC BW 50 kHz Analog Input board EN 2 2 flatness adjust R276 Ze 8146 NTSC BW 50 kHz R304 2 level adjust R138 Chroma Filter R186 flatness adjust C922 Chroma Filter _ level adjust TP610 CAL DAC _ co o pem m R476 ES ES E 335 EE s ADC board 550 B a Y 1165 MID FRE R138 L TP86 gt A GAIN PAL VCO adjust mmm 0 HIGH FREQ NTSC VCO adjust 5 2 ss n i TP17 GND Genlock board T TP15 4CLK TP12 CLK Figure 5 1 Adjustment locations 14 Touch the Zero Set soft key to set the measurement reference for the internal oscillator 15 Connect the signal generator full field and burst to the channel A input terminate the loop through with a 75 Q BNC termination VM700T Video Measurement Set Service Manual 5 5 Adjustment Procedure 5 6 Adjust Filter Flatness 16 Check that the burst frequency measurement is 0 10 Hz using the internal frequency reference Do this procedure for NTSC and PAL TV signals if the VM700T is a dual standard instrument NOTE If the VM700T meets the limits described skip step 17 Adjusting the VM700T unnecessari
2. 14 on the A18 Acquisition Memory board Power bus cable VM700T top view Figure 6 14 Disconnecting the Analog Input board connectors 6 24 VM700T Video Measurement Set Service Manual Maintenance Figure 6 15 Removing the attachment screws from the Analog Input board s signal input connector plate 2 Perform following steps to replace Analog Input board Carefully place the board in the VM 700T chassis by guiding the signal input connectors through the slot in the rear panel and positioning the board on its bulkhead standoffs Replace the eight board retaining screws and then replace the screws holding the signal input connector to the instrument rear panel see Figure 6 15 Connect the ribbon cable at J965 see Figure 6 14 for cable locations Connect the wire at J132 and the shielded cable at 16 Replace the wire connecting A4 J915 to A1 1922 Replace the wire connecting A4 J418 to A1 1923 Install the power bus cable on its five connectors Install the cover panel refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 25 Maintenance Genlock Board Removal 6 26 and Replacement Removing the Genlock board A2 consists of removing the VM700T top and right side cover p
3. Equipment Minimum specification Purpose Example Coaxial cable 2 required 15 Q impedance high Signal interconnections Tektronix part number quality noise free 1 meter 012 0074 00 length Termination 75 Q precision BNC connec Signaltermination Tektronix part number tors 011 0102 01 Alignment tool Non metallic flat blade Adjust potentiometers and Tektronix part number capacitors 003 1364 00 Screwdrivers Pozidriv 1X and 2X Remove and replace cover panel screws Gain phase analyzer 15 Q impedance Extended flatness adjust Hewlett Packard 4194A ment Impedance Gain P hase analyzer Feed through termination 75 Q impedance BNC Signal termination Tektronix part number connectors 011 0055 01 Adapter 2 required BNC female to SMB male Signal interconnections for Omni S pectra snap on connector extended flatness adjustment 3280 2224 00 1 The example amplitude calibrator requires TEGAM TM500 or TM5000 series power module 2 The flatness accuracy required of the leveled sine wave generator is only to the bandwidth needed to perform the VM700T verification and adjustments It is not specified to be that flat over the entire bandwidth of the generator 3 Omni Spectra is MACOM company 140 Fourth Avenue Waltham MA 02254 USA or 77 Milford Road Reading Berks RG1 8LG England The example connector is a distributor part System Adjustment Procedures NOTE This equipment requires a 20 min
4. 6 100 SDI Option Diagnostics DER He he HEE ES EOE OSES wha ees 6 104 Options Standard Options Option 01 and Option 11 7 1 Application Options Option 1G Option 20 Option 21 Option 30 Option 42 7 1 Audio Options Option 40 and Option 41 7 3 Serial Digital Interface Option 15 7 4 GPIB Interface Option 48 ste RE RU A ET REN CN dcs 7 4 White Phosphor CRT Option 74 7 4 Cabinet and Mounting Options Option IC VM7FR1 VM7FC1 7 5 Auxiliary Software Options VMBKUP VMT VMREMGR 7 5 Optional Accessories 1 ce vecti LECKER eed ML E eda 7 5 Power Cord Options re eee y ee x ea 7 6 Replaceable Electrical Parts Diagrams Block Diagram Rees PES eee he So Edere des 9 1 Interconnection Diagram proe dune bet E ATUS 9 1 Replaceable Mechanical Parts Parts Ordering Information 10 1 Using the Replaceable Mechanical Parts List 10 1 iv VM700T Video Measurement Set Service Manual Table of Contents List of Figures Figure 2 1 Power line conditioner with rackmounted VM700T 2 3 Figure 2 2 VM700T Startup menu 2 5 Figu
5. VM700T Video Measurement Set Service Manual 2 1 2 1 2 1 2 2 2 2 2 3 2 4 2 4 2 7 2 8 Table of Contents Wavetorm Mode esca queda e Sacs ee gne dos 2 8 Vector Mode 2 8 Measure dE E 2 9 Picture Mode acero E E A 2 9 Auto Mode EP ERAS d 2 9 Analog Digital Mode Option 18 Only 2 9 User Programmable 2 10 sas ed ee thy e RO me SL HE eM d 2 10 Remote Operation 225222259222 5542 d EE 2 10 Front Panel Controls REPE T TES 2 11 TOUCH GGG eae ts 2 11 Keypad vega RR SE REPE REPE E QN P Nd 2 12 Control Knob UR LAG ES 2 14 Equipment Signal Sources Required 2 15 dy 2 15 Connecting Inputs and 2 15 Rear Panel and Connections i ions beni Rede me Rd E Pd 2 16 Equipment Video Signal Sources Required 2 18 Connecting Audio Option 40 toa Source 2 19 Input Connector Pin Assignments 2 19 Connecting Audio Option 41 toa Source 2 20 Option 41 Audi
6. Figure 2 8 The VM700T Video Measurement Set front panel Touch Screen The display CRT area of the measurement set has a touch screen interface for communicating with the measurement set You touch the soft keys on the screen to select and control many operations of a running application When applicable you can change selection values within a soft key by rotating the large control knob You also use the touch screen interface to edit the configuration files that control the operation of the measurement set The place you touch the screen is also the zoom point for expanding or contracting a displayed waveform VM700T Video Measurement Set Service Manual 2 11 Operating Information Keypad 2 12 The keypad shown in Figure 2 9 contains three five button rows plus an additional five buttons associated with the control knob VM700T MEASUREMENT SET turbo Waveform r Picture Measure Auto 5 s s SOURCE B Average Function Copy Freeze Menu Hel s o 2 Configure Select Line HH Lr Intensity Q Display Graticule Figure 2 9 Measurement set keypad Manual and Auto Operational Modes The top row of buttons selects the major functions operating modes of the measurement set The measurement set has five operational modes four manual modes and an automatic mode
7. Measure Mode oes RR CREW AES RES ADD OU NTSC Measurement Specifications Measure Mode ra ELE poe espe gine heehee bees Auto MOd Lii REPRE PEDES PR SERE RU Re CAE eds Audio Option 40 Option 41 and Option 42 Specifications Automatic Audio Test Specifications 0 0 urere eee eee Audio Analyzer Specifications Audio Spectrum Specifications Multitone Analyzer Specifications A V Timing Specifications Option 42 Option 48 GPIB Specification Option 15 SDI Specification 2 cick ea hak eh veda E Installation 222202256 nese xev pede UR or pO aea e pof S eoe Power Requirements Changing Line Voltage Range and Power Cord t pROEP3 eig e MER Ate REEL beg Power Line Conditioner Accessory Installing the Power Line Conditioner Power On Di3grnostl68 Du PER Ier ERR ERI ELE Ya E eura Calibrating the Touch Screen 22222252255 ERR ERES PES Setting the Power On Mode Measurement Set Operating Modes
8. 2 09 mat B Vertical 552 Centering Figure 5 3 Display monitor centering adjustments 9 After making the adjustment requested and storing the current setting second set of instructions is displayed as shown in Figure 5 5 Follow the directions given in the screen to calibrate the touch panel to the CRT display TOUCH PANEL INTERFACE CAL DISPLAY Use the knob to adjust horizontal position and squareness of the screen border lines Press AUTO button to abort or any other to accept and store current setting Current Setting 8 Figure 5 4 Touch screen calibration display VM700T Video Measurement Set Service Manual Adjustment Procedure TOUCH PANEL INTERFACE CAL PANEL press AUTO to abort TOUCH THE DOT INSIDE THE SQUARE Place finger tip directly over the dot being careful to avoid parallex touching the dot until the square highlights and beeper sounds SQUARE LOCATIONS SEQUENCE Screen SQUARES will appear near Screen corners 1 2 5 will be 32 248 1 2 3 4 as indicated to the right Figure 5 5 Touch screen calibration panel 10 After the dots at all four corners have been touched a screen displaying the panel calibration factors is displayed as shown in Figure 5 6 From that screen you can press any key to return to the VM 7
9. C Bandpass is too wide and peaked Adjust C436 and D Typical correct flatness curve All points curve within C335 for best flatness on all channels 30 mdB to 8 MHz Figure 5 7 Example gain phase analyzer flatness waveforms for the VM700T VM700T Video Measurement Set Service Manual 5 17 Adjustment Procedure 21 Reinstall the cables and jumpers removed in step 9 to their original positions but leave the SMB cable between the Analog Input board and the ADC board disconnected 22 Set the marker on the gain phase analyzer to 6 MHz and check that the frequency response is flat within 30 mdB peak to peak see Figure 5 7 NOTE If the VM700T meets the limits described in step 16 skip step 17 23 If the frequency response is outside the limits specified in step 16 adjust C436 on the filter switch board to bring it into specification Re verify that all channels meet specification after adjusting C436 Capacitor C335 may also require adjustment to attain the proper response curve limits Adjust ments of C436 and C335 are interactive and may need to be repeated several times to obtain the best response curve 24 Reconnect the SMB cable between Analog Input board and the ADC board 1550 to J765 and connect the gain phase input cable to J2 on the ADC board 25 Set the controls on the gain phase analyzer as needed For the example gain phase analyzer the controls are set as shown in the following gain phase
10. SDI Option 1S Performance Verification Preliminary Setup SDI Analog Ref Input Eye Diagram Application Jitter Application Interchannel Timing Application SDI Output Adjustment Procedure Test Equipment Required System Adjustment Procedures Extended Adjustment Procedure Option 1S Adjustment Procedure Maintenance Servicing Preparation Inspection and Cleaning Repackaging the Instrument Removal and Replacement Instructions VM700T Rack Mounting Instructions Troubleshooting Procedures VM700T Video Measurement Set Service Manual 3 37 3 39 3 40 3 41 3 43 3 43 3 45 3 48 4 1 4 6 4 7 4 13 4 13 4 15 4 15 4 17 4 18 4 19 4 19 4 20 4 22 4 23 4 25 4 26 4 27 4 28 4 30 4 34 4 35 5 1 5 2 5 14 5 21 Table of Contents Troubleshooting Techniques 6 50 Isolating Operational Faults 6 51 Diagnostiese re abc e ere E RR 6 55 Troubleshooting the Power Supply and CRT Display 6 90 Troubleshooting Option 40 and Option 41 6 95 Troubleshooting Option 48 GPIB 6 99 Troubleshooting Option IS SDD
11. 0 5 for Bar and 0 5 IRE for no Zero Carrier and Horizontal Blanking Horizontal Blanking FCC Multiburst FCC Multiburst or NTC 7 Combination Table 1 79 Incidental Carrier Phase Modulation Measurement ICPM requires Zero Carrier Pulse and the quadrature output of the demodulator on channel C 1 26 Range Accuracy VM700T Video Measurement Set Service Manual Measurement specifications or NTC 7 Combination FCC orNTC 7 Composite Specification Table 1 80 Color Bar measurements Measurement Color Bar Amplitude Errors Color Bar Phase Errors Color Bar Chrominance to Luminance Gain Ratio 100 of nominal FCC Color Bars 180 from nominal FCC Color Bars 0 to 200 of nominal FCC Color Bars Table 1 81 Out of Service measurements Measurement Field Time Distortion Range 0 to 40 Accuracy 30 5 Test signal Field 9quare Wave Table 1 82 Waveform Distortion measurements Measurement Line Time Distortion 0 to 40 of Bar 10 296 FCC orNTC 7 Composite Pulse to Bar Ratio 1096 to 125 50 796 FCC orNTC 7 Composite Short Time Waveform 0 to 25 SD 0 5 SD NTC 7 Distortion IEEE 511 Composite Chrominance Nonlinear Gain Distortion 5 IRE to 35 IRE 0 4 IRE NTC 7 20 IRE chroma Combination Chrominance Nonlinear Phase Distortion Chrominance to Luminance Intermodulation 2T K Factor Table 1 83 VIRS measurements Measurement VIRS
12. Possible channel selection combinations hardware A B Figure 3 1 Analog input board A1 block diagram Differential Amplifier differential amplifier combines the differential output of the switching matrix and produces a single ended video output signal which is connected by coaxial cable to the filter switch board After being filtered if filtering is needed the video signal returns to the analog input board for offset gain and dither processing 3 4 VM700T Video Measurement Set Service Manual Theory of Operation An acquisition description supplied by application software causes the acquisi tion controller board to dynamically apply dynamic offset programmable variable gain and dither to the input video Dynamic Offset Generator Data bits from the acquisition controller board drive the dynamic offset generator and Offset Amplifier DAC and provide a dynamic offset range of 1 28 to 1 27 volts in 10 mV steps This offset is summed with the video signal to keep the signal centered in the dynamic range of the analog to digital converter ADC The video signal with offset applied is buffered by the offset amplifier and passed to the variable gain amplifier Variable Gain Amplifier variable gain amplifier consists of a resistive divider range switch followed by an amplifier with continuously variable voltage controlled gain The control voltag
13. CAUTION The following Cable Meter adjustment step requires three signals to N complete a 525 line 143 MHz NTC7 combination signal a 525 line 270 Mb 100 color bars signal and any 525 line 360 Mb television signal Do not perform this adjustment unless you have all three signals or you will misadjust the instrument 3 Perform the following steps to adjust the Cable Meter a Touch the Cable soft key NOTE Performing the cable meter adjustment requires two cable lengths 3 meters and 100 meters If you are using a cable clone to simulate 100 meters use 3 meters of cable with the cable clone as shown in Figure 5 11 b If you are using a cable clone for this adjustment connect a 525 line 143 Mb NTC7 combination signal from the digital television signal generator to the cable clone input Connect the cable clone output to the SDI Ch A input Be sure the SDI Ch A loopthrough is terminated using a 75 2 high frequency terminator If you are using 100 m of cable for this adjustment connect a 525 line 143 Mb combination signal from the digital television signal generator to the SDI Ch A input using a standard length cable 1 m length Be sure the SDI Ch A loopthrough is terminated using a 75 high frequency terminator 22 CE 3 meter cable Cable clone 92 lt Totalleng
14. Replaceable parts list cont Fig amp index number 37 38 39 40 41 42 43 44 45 46 41 48 49 50 51 52 53 54 54 55 56 57 58 59 60 61 62 64 10 6 Tektronix part number 337 3448 00 211 0507 00 220 0625 00 671 1922 02 441 1814 01 337 3972 00 212 0040 00 337 3660 00 337 3661 00 174 0844 01 407 3613 00 211 0661 00 343 0088 00 119 4258 04 11 0507 00 10 0409 00 10 0458 00 12 0189 00 NN 134 0245 00 337 3653 00 211 0661 00 407 4290 00 211 0504 00 337 3670 00 337 3669 00 337 3532 00 348 1583 00 211 0516 00 Serial no effective B020100 B030422 Qty 12 12 Name amp description Mfr code SHIELD ELEC CRTVM700T 5Y400 SCREW MACHINE 6 32 X 0 312 PNH STL POZ TK0435 NUT SHEET SPR 6 32 STLCLIP ON TYPE 78553 CIRCUIT BD ASSY DISPLAY A14A1A1 80009 CHASSIS CRT VM700T 0 260 SHIELD EMI 337 3648 00 337 3660 00 337 3661 00 80009 ASSEMBLED SCREW MACHINE 8 32 X 0 375 FLH 100 TK0435 DEG STLPOZ SHIELD ELEC 7 46 LBE CU CLIP ON TOP 30817 SHIELD ELEC 6 46 L BE CU CLIP ON LEFT 30817 CA ASSY SP ELEC 8 22 AWG 16 18 L RIBBON 9M860 BRACKET CA HSG CABLE HOUSING 0 260 BRACKET VM700T SCR ASSEM WSHR 4 40 X TK0435 0 25 PNH STL POZ MACHINE CLAMP CABLE 0 062 DIA PLASTIC 80009 POWER SUPPLY IN 115 230 47 63 HZ OUT 5V 40A 80009 15V 15V 3A 12V2 5A 5 2V 8A VAR FAN OUT 9 29V A15 S
15. SDI Output lt Analog Ref SDI Option Interface gt AES EBU Digital Audio LTC Tine Code gt bus ChA ChB ChA 12 A13 ChB GPIB Port VM700T Video Measurement Set Service Manual Audio Option Analog video to ADC Video to filter switch Filter switch Filtered video Filter select and control bus Datta and control bus 2 Frarre line and sarrple check 11 Main interconnect left and right 19 GPIB Option Alarmsignals 15 Power supply Printer 16 OPS fail ON OFF Overtenp O Power Figure 9 1 VM700T Video Measurement Set simplified block diagram ChAIn 5 1619 J550 2 6 1765 Trace Rotation ChAOuG 9 ADC E 2 ChB In G Touchscreen Filter Switch 1 Analog Input Video In Jiu J995 ChB Out G Isio 1922
16. Table 1 39 Field Blanking timing measurements Table 1 40 Other Timing measurements Table 1 41 Amplitude and Phase measurements Table 1 42 Frequency Response measurements Table 1 43 Waveform Distortion measurements Table 1 44 Low Frequency Error Table 1 45 Noise measurements Table 1 46 Incidental Carrier Phase Modulation Table 1 47 Bar Line Time Table 1 48 Bounce Table 1 49 Burst Frequency Table 1 50 Chrominance to Luminance Gain and Delay Table 1 51 Chrominance Frequency Response Table 1 52 Chrominance Noise Table 1 53 Chrominance Non Linearity Table 1 54 ColorBar Table 1 55 SMPTE color bar nominal values VM700T Video Measurement Set Service Manual 1 11 1 11 1 11 1 11 1 11 1 12 1 12 1 12 1 12 1 13 1 13 1 13 1 13 1 13 1 13 1 14 1 14 1 14 1 14 1 14 1 15 1 15 1 15 1 16 1 16 1 17 1 17 1 18 1 18 1 18 1 19 1 19 1 20 1 20 1 20 1 20 1 20 1 20 1 21 Table of Contents Table 1 56 Table 1 57 Table 1 58 Table 1 59 Table 1 60 Table 1 61 Table 1 62 Table 1 63 Table 1 64 Table 1 65 Table 1 66 Table 1 67 Table 1 68 Table 1 69 Table 1 70 Table 1 71 Table 1 72
17. mV Diagram F2 197 scanning 270Mb 525 line Auto detect Adjust eye crossing to 0 15 UI 0 2 0 0 0 2 0 4 0 6 0 8 1 0 1 2 Unit Intervals Filter 1 Khz DC OffsetiO0 5 mv Rise Fall Adjusted on Cable Len Bel 8281 22 meters Mode Waveform Cursors Rescale Eye Units 2 Figure 5 13 Adjusting the eye crossing horizontal position t Touch the Horz Pos 270 Mbit soft key to save the adjustment A wait message will appear Replace the 270 Mb signal on the SDI Ch input with a 525 line 360 Mb television signal v Check that the readout text in the upper right corner of the display reads 360 Mb w Touch the Horz Pos 360 Mbit soft key X Turn the front panel knob to the left eye crossing to approximately 0 15 UI 0 4 ns on the horizontal scale See Figure 5 13 y Touch the Horz Pos 360 Mbit soft key to save the adjustment A wait message will appear VM700T Video Measurement Set Service Manual 5 29 Adjustment Procedure ab ac ad ae af Press the VM700T front panel Menu button Touch the Waveform soft key and then deselect the Falling Edge and Non Transitn soft keys leave only Rising Edge selected Touch the Calibrate soft key and then touch the Delay4 soft key Turn the front panel knob to center the displayed rising edge of the signal See Figure 5 14 Touch the Delay4 soft key to save the adjustment A wait message will appear
18. 2 Perform the following steps to replace the I O board a Guide the board onto the card cage track and slide it into the card cage see Figure 6 4 Align the circuit board connector pins with the connector on the main interconnection board and press firmly to seat the connector Replace the circuit board retaining screw Replace the circuit board center support and screw Replace the cover panel refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 9 Maintenance Figure 6 3 Removing the left card cage center support Figure 6 4 Installing the I O board in the card cage VM700T Video Measurement Set Service Manual 6 10 Maintenance Option 40 and Option 41 As you face the front of the VM 700T in its operating position the Audio Audio Boards Removal Processor A12 and Audio Analog A17 boards are located in the left side card and Replacement cage with the I O board A20 and if installed the GPIB Interface Option A19 board You may use these procedures to remove and replace both boards To remove these boards you must first remove the left side cover panel to gain access Then remove the retainers and screws holding the boards in the card cage If you are removing only one of the boards first remove the flat cable between the boards at connector J9 Otherwise leave the flat cable connected and remov
19. 2 Perform the following steps to replace the VGA Connector board a b Reconnect the VGA ribbon cable to the connector on the circuit board Position the VGA Connector board on the mounting plate against the inside surface of the rear panel under the fan housing Align the holes in the circuit board with the holes in the rear panel mounting plate and install and tighten the attaching hardware Replace the cover panels refer to Cover Panel Removal and Replace ment on page 6 8 VM700T Video Measurement Set Service Manual 6 43 Maintenance VM700T Rack Mounting Instructions Unpackaging Power Requirements Changing the Line Voltage Range and Fuse 6 44 When unpackaging the VM 700T Video Measurement Set for installation keep the shipping carton and packaging material If returning the VM 700T for repairs should become necessary you will then have packaging available that will provide adequate protection for shipment The VM 700T will operate with line frequencies of 50 Hz or 60 Hz over two line voltage ranges The low voltage range is from 90 VAC to 132 VAC 115 VAC nominal The high voltage range is from 180 VAC to 250 VAC 230 VAC nominal WARNING For your protection and to avoid damage to the measurement set shut the power off before removing or replacing any circuit boards connectors or jumpers The voltage range selection switch and fuse holder are located on the lower left corner of
20. 5 Weighting filter as per CCIR 468 4 recommendation VM700T Video Measurement Set Service Manual 1 29 Specification Table 1 86 Tektronix automatic audio test measurement specifications Measurement Range Accuracy includes flatness Insertion Gain Error 6 dB 0 2 dB Sweep Gain Min and Max 12 dB 0 1 dB THD N lt 0 03 to 70 10 1 digit Crosstalk into channel 1 dB Test Level 6 dBu lt 66 dB to 0 dB 0 dBu lt 60 dB to 0 dB 6 dBu lt 54 dB to 0dB SNR weighted 2 dB Test Level 6 dBu 10 dB to gt 90 dB 0 dBu 10 dB to gt 90 dB 6 dBu 10 dB to gt 84 dB ANSI Crosstalk into channel 0 to 10 dB 0 20 ANSI SNR weighted 2 dB Test Level 6 dBu 10 dB to gt 90 dB 0 dBu 10 dB to gt 90 dB 6 dBu 10 dB to gt 84 dB Max Compandor Error rise fall 6 dB 0 2 dB Gain Difference 12 dB 0 2 dB Phase Difference 180 to 180 il 1 Assumes insertion gain is within 6 dB 2 The measurement range specification assumes that the input level is within 6 dB of the 0 33 test level in the audio configuration The actual O 33 test level range is 6 dBu to 14 dBu 3 The weighting filter is a 15 kHz sharp cutoff low pass filter 1 30 VM700T Video Measurement Set Service Manual Specification Audio Analyzer Specifications Table 1 87 Frequency and Noise specifications Measurement Specification Comments Level Maximum Allowable Input 430 24 5 V rms Re
21. For information on how to return defective instrument modules to Tektronix for repair refer to Customer Service on page 6 3 Table 6 3 lists a series of instrument faults or failures related possible causes and suggested corrective actions Run the complete set of diagnostic test to determine if suspected modules pass or fail the testing before attempting any module exchanges You can use the information in the table along with the results of the diagnostic tests to characterize faulty VM 700T operation as a repair guide VM700T Video Measurement Set Service Manual 6 51 Troubleshooting Procedures Table 6 3 VM700T symptoms and corrective actions Symptom No display blank screen Possible cause Faul Faul Loose Cables ty power supply ty CRT Corrective action Check power supply Refer to Troubleshooting the Power Supply Connecta VGA monitor to the rear panel VGA connector and check for a display If the VGA signal is good replace the CRT display assembly Refer to Removing and Replacing the CRT Assembly Check for loose AC line cord CRT connector or power supply connections To gain access to the CRT connector refer to Removing and Replacing the CRT Assembly To gain access to power supply connections refer to Removing and Replacing the Power Supply Blown mains line fuse Check fuse on rear panel Refer to Troubleshooting the Power Supply Faul ty CPU
22. NOTE The VM700T and Option 15 must be warmed for at least 20 minutes before you perform the Option 15 performance verification procedures VM700T Video Measurement Set Service Manual SDI Option 1 Verification SDI Analog Ref Input The amplitude range specification for the SDI Analog Ref input is 6 dB with respect to 1 video Perform the following procedure to check the amplitude range of the SDI Analog Ref input 1 VM700T Video Measurement Set Service Manual Connect an NTSC black burst signal to the Option 15 Analog Ref input Terminate the signal using two 75 feedthrough terminators in series with one 50 feedthrough terminator provides a 0 5 signal Connect a 270 Mb 525 line 10046 color bars signal to the Option 1S SDI Ch A input Terminate the SDI Ch A input using a 75 2 high frequen cy terminator Set the digital television signal generator for a vertical delay of 262 lines on the 10046 color bar signal Press the Source A button to select channel A for display and then press the VM700T front panel Measure button Touch the SDI IC Timing soft key Press the front panel Menu button and then touch the Relative Analog soft key Check the measurement reading m VM700T firmware version 980422 and below 16 mSec to 17 m 700 firmware version 990512 and above 16 to 17 Remove the three terminators from the signal on th
23. The Picture Monitor produces the visual display of the VM 700T It is has vertical and horizontal deflection circuitry to drive the trace on the raster scan CRT a video amplifier the high voltage circuitry and the CRT in a complete assembly A simplified block diagram is shown in Figure 3 12 Video Amplifier Video Amplifier amplifies the incoming video signal to levels necessary to drive the CRT cathode A input circuit provides impedance matching and current drive to the output video amplifier The output video amplifier drives the CRT cathode As the input video signal is increasing in amplitude the inverted video signal drives the cathode negative with respect to its 55V reference level thereby causing the beam current to increase 12 V and 5 V Supplies The incoming 12 V is filtered to provide the 12 V supply A second 12 V 12 V1 is obtained through R295 That voltage is applied to a 5 V zener diode to supply a 5 V source Vertical Deflection vertical deflection circuit provides the drive current to the vertical deflection yoke free running oscillator circuit produces a ramp signal and an amplified vertical deflection signal The basic frequency of the oscillator is set to 60 Hz by the adjustment of the VERT HOLD potentiometer The length of the ramp signal and consequently the vertical synchronization is set by the V Sync signal When the V Sync is received the vertical ramp is terminated and a new one
24. 30 Hz 100 Hz 1 kHz 5 kHz 12 kHz 20 kHz Amplitudes 10 dBu 21 dBu 40 dBu 49 dBu 51 dBu 55 dBu 59 dBu 61 dBu 65 dBu 70 dBu 6 Setthe sine wave generator for each of the frequencies and amplitudes you have selected to test 7 At each frequency check that the measured level is accurate to the limits shown record the level for each frequency 8 Verify that any differences between the measured levels recorded for each frequency are within the flatness specification given in Table 4 3 4 16 Nov 1994 VM700T Video Measurement Set Service Manual Audio Option 40 Verification Procedure Check Distortion and Distortion Measurement Accuracy This procedure verifies that residual THD N is 0 03 or less and then checks the THD N accuracy of the audio option by reading a known signal Specification Checked THD N accuracy is 10 of the reading 1 digit for harmonics at input levels of 20 dBu or greater in a 33 Hz to 22 kHz bandwidth Option 40 Distortion 1 Check residual THD N Measurement Accurac Apply Signal between 20 dBu 30 dBu in amplitude from sine wave generator to the VM700T Audio Option 40 See Figure 4 7 for a cabling diagram The generator should be set at 500 output resistance To Option 40 audio input connector p OOo Figure 4 7 Option 40 cable connections distortion measurement accuracy check
25. A control signal used to hold off the 2 034 MHz When the signal is low the 2 034 MHz is not generated The signal is generated only when diagnostics are run or when a new control word is written for changing gain or attenuation The DAC is an 18 bit D A converter Serial digital data sent by the DSP and a clock signal that is replicated by the DSP are applied to the DSP A shift register realigns the 24 bit data from the DSP so that valid data is shipped to the 18 bit DAC The DAC expects leading not trailing zeros so the shift register shifts the data six bits for proper alignment This DAC circuit is used in diagnostics discussed later The output of the DAC is a current signal is converted to a voltage signal VM700T Video Measurement Set Service Manual Theory of Operation Floating Power Supply Grounds The mainframe interconnector provides 5 V and ground from the VM 700T The 5 V powers two low noise high accuracy switching supplies One supply provides 5 volts at 1 ampere the second switching supply provides 15 V and 15 V at 330 mA This floating power supply isolates the analog circuitry from possible noise sources in the VM 700T power supplies The and 15 V supplies are used to provide regulated and 5V to the analog board through three terminal regulators These and 5 volt analog supplies power the A D converter and the DAC Several different grounds are used in the instrument The grounds ar
26. Analog ground m Clamp levels for channels A B and C m TEMPSENSE from a thermistor m REF output from the precision voltage reference VM700T Video Measurement Set Service Manual Theory of Operation The Genlock Board A2 Sync Stripper Crystal Oscillator The genlock board sends a constant frequency sampling strobe to the analog to digital converter ADC board The NTSC and PAL television standards are supported by both the genlock board and application firmware A block diagram of the genlock board is shown in Figure 3 2 The sampling strobe may be generated by one of the following three methods or modes The strobe may be phase locked to the incoming video signal synchronous sampling mode to force 910 NTSC or 1135 PAL samples per line The strobe may be phase locked to an internal crystal oscillator running at 20 25 MHz asynchronous sampling mode This method of generating the sampling strobe avoids errors that could be caused by unstable signals typically found in video cassette recorders VCR When timing measurement precision is most important or when greater timing resolution is desired the strobe may be exactly 20 25 MHz 20 25 MHz sampling mode This mode of operation eliminates the small timing errors inherent in phase locked loop systems In addition the genlock board sends line and frame sync strobes to the ADC board The sync stripper removes all luminance and chrominance information from
27. Install the seven board retaining screws Connect the wire at J10 Connect the flat 10 conductor cable between J111 on the ADC board and J6 VM700T Video Measurement Set Service Manual Maintenance 5 O Power 7 bus cable y gel onthe VM700T top view 18 board 8 on the A2 board k 22 212 22222 J10 A2 J6 Ji Figure 6 16 Removing the Genlock board e Install the power bus cable at its five connectors f Connect the interconnection ribbon cable from the Acquisition Memory board to J8 of the Genlock board Install the card cage retainer refer to step 4 on page 6 17 h Install the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 27 Maintenance ADC Board Removal and 6 28 Replacement Removing and replac
28. Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu Calibrate TOUCH PANEL INTERFACE az Reprint 8 Abort Menu Input your selection Figure 5 2 VM700T startup menu 6 Inthe startup menu use the large control knob to highlight the T in the Calibrate Touch Panel Interface line Press the Select Line button to make the selection to calibrate The first touch screen calibration instructions are then displayed as shown in Figure 5 4 7 Usethe large control knob to set the current setting to 8 This setting provides the best centering for a connected VGA monitor 8 Check the horizontal and vertical centering of the display If display positioning is not satisfactory off center or horizontal folded back adjust the appropriate control Horiz or Vert Centering located beneath the side retainer plate on the A5 CPU board board right side of the VM700T see Figure 5 3 to align the display on the CRT VM700T Video Measurement Set Service Manual 5 11 Adjustment Procedure lt
29. Remove the circuit board retaining screw from the appropriate circuit board NOTE It may also be necessary to remove or loosen the circuit board retaining screw immediately above the circuit board you are removing If you are removing only one of the audio option boards disconnect the flat cable between them at J9 Unplug the circuit board using the ejector tab to release the board from the main interconnection board Remove the board from the card cage Perform the following steps to install the Audio boards a Guide the audio boards onto the card cage track and slide it into the card cage connector see Figure 6 4 Align the circuit board connector pins with the main interconnection board connector and press firmly to seat the connector Replace the circuit board retaining screw Replace the circuit board center support and screw If you disconnected the flat cable at J9 replace it now otherwise verify that the cable is seated correctly in the connectors Replace the carrying handle cover and screws The VM 700T with Option 41 includes 37 pin connector located on the instrument back panel Pin assignments for the connector are listed in Table 6 2 Table 6 2 Audio Option 41 connector pin assignments 1 Audio input Signal Signal Shield 1 Left 1 2 3 1Right 21 22 20 2 left 4 5 6 2Rght 24 25 23 3 Left 7 8 9 3 Right 27 28 26 For single ended input connect single ended inp
30. b Runthe Audio Analyzer measurement and verify that residual THD N is 0 03 or less An applied signal of 8 dBu to 10 dBu yields optimal reading while a 20 dBu signal yields a worst case reading 2 Check THD N Measurement Accuracy a With 600 Q output resistance selected connect the outputs of two sine wave generators in parallel to the left channel input of the Audio Option See Figure 4 7 for a cabling diagram b Set one sine wave generator for a 2 VRMS output at 1 KHz VM700T Video Measurement Set Service Manual 4 17 Audio Option 40 Verification Procedure Setthe second sine wave generator for a 0 02 V 20 mVRMS at 3 kHz These two signals add across the termination resistance to produce a 1 kHz signal with a 1 third harmonic distortion d Runthe Audio Analyzer measurement and check for a THD N reading of 0 9 to 1 1 3 Move the input from the generators to the right channel and repeat step 2 part d Check Frequency and Phase Measurement Accuracy This procedure requires an accurate frequency sine wave generator or a digital counter to accurately set the frequency The phase measurement requires that both channels have the same signal applied through equal length cables Specifications Checked This procedure checks the following parameters m Frequency accuracy 1 Hz or 0 0146 1 digit whichever is worse for inputs of 60 dBu or greater in the frequency range of 20 Hz to 20 kHz
31. 10 Bit ADC The 10 Bit ADC block is used to generate the samples for the eye diagram and for the jitter waveform When fed the raw SDI signal and clocked by the output of the High Performance Clock Recovery block the ADC generates Eye information When fed the control voltage from the jitter demodulator it generates the jitter waveform Wander Detector The Wander Detector block uses a high precision oscillator to provide the time base for precise measurement of minute differences in the interval between TRS marks This timing information is sent down the analog data path for further processing by the instrument software SDI Regenerator The SDI regenerator takes the signal from the equalizer for use as the SDI signal to be output It does not regenerate the clock NOTE The signal from the SDI Ch A input to the SDI regenerator is interrupted whenever an analog application is run AES Audio Receiver The AES audio receiver recovers the external audio serial data stream It outputs a serial data stream that is converted to parallel data by the audio video MUX VM700T Video Measurement Set Service Manual Theory of Operation Analog Sync Detector The analog sync detector recovers line and frame Sync from the Analog Reference input signal LTC Receiver The LTC Receiver block translates the LTC signal into registers that can be read by the CPU Modified Acquisition modified Acquisition Memory board contains all the an
32. Amplitude accuracy at 67 5 MHz 3 Amplitude flatness at550 MHz 4 of 50 kHz reference Checking Eye Diagram Tektronix 56 50301 amplitude accuracy and frequency response Digital television signal generator Television signal generator Coaxial cable BNC connectors Terminations SMPTE 259M SDI signals 270 Mb 525 line 100 color bars 143 Mb 525 line NTC7 combination 360 Mb 525 line 10 step SDI signal jitter Amplitude range of 0 to 15 ns 10 at 2 ns Frequency range of 50 Hz to 10 MHz Variable vertical signal timing of 262 lines Nominal NTSC video signal synchronized with a serial digital test signal 3 75 impedance Belden 8281 1 meter length 75 precision high frequency 26 dB to 300 MHz BNC connectors 50 precision SMA connectors 50 feedthrough BNC connectors 2 75 Q feedthrough BNC connectors Serial digital television test signal source Tektronix TG2000 Signal Generation Platform DVG1 generator module with Option 51 Analog television signal source Tektronix TG 2000 Signal Generation Platform BG1 module Signal interconnections Tektronix part number 012 0159 00 Signal termination Tektronix part number 011 0163 00 Signal termination Tektronix part number 015 1022 00 Checking the Analog Ref Tektronix part number input 011 0049 01 Checking the Analog Ref Tektronix part number input 011 0055 01 SMA to BNC adapter SMA female to BNC male T
33. J418 A10A2 Keyboard CnCIn G J915 y 1148 1540 ChC Out G Jao ExtSyncIn s J210 A2 Geniock X EE 10 10 A10 Ext Sync Out 6 Frot Pana J 933 no gt 110 J6 A21 J8 VGA 123 HoH n SDI Option 5 Interface SDI Ch A E Green um Pi COMO m 10 SDI Ch B 18 A20 CPU VO Y 16 17 19 1 soo amp Yellow J10 5 Je Printer T Analog Ref 1 1200 AES EBU fh 3 58 Digital Audio S LTC Tirre Code S 11 Main Interconnect left and right J 246 H2 V to Display Monitor 256 254 1244 124255 J25 25 1252 16 2 H H H 4 ON OFF W245 J140 LE 2 8 Figure 9 2 VIMI700T Video Measurement Set interconnection diagram 9 4 VM700T Video Measurement Set Service Manual See Replaceable Mechanical Parts This section contains a list of the replaceable mechanical components for the VM700T Video Measurement Set The replaceable modules are also included in this parts list as well as in the Replaceable Electrical Parts List Use this list to identify and order replacement parts Parts Ordering Information Replacement parts are available through your local Tek
34. Table 1 73 Table 1 74 Table 1 75 Table 1 76 Table 1 77 Table 1 78 Table 1 79 Table 1 80 Table 1 81 Table 1 82 Table 1 83 Table 1 84 Table 1 85 Table 1 86 Table 1 87 Table 1 88 Table 1 89 Table 1 90 Table 1 91 Table 1 92 Table 1 93 Table 1 94 Differential Gain and Phase 1 21 Frequency Response and Group Delay 1 21 Honzontal Blanking eee ene ur eos wale RES 1 21 Horizontal Timing ERR ERIS 1 21 Incidental Carrier Phase Modulation 1 22 JE 1 22 1 22 Level Meter Sunde etd deed ori ded Sie en ee 1 22 Liane Frequency eu isse e Lebe RR bid OC PRAE ewe x 1 22 Luminance Non Linearity 1 23 Multib tst ritis Dues EP 1 23 Noise Spectrum srein riese piere PR MERITIS 1 23 SCH EEG nere Ra px 1 23 short Time Distortion 32 eR REO np 1 23 Twobield 252 cese Ge Dent 1 23 TSD 1 24 Vertical Blanking ERES 1 24 RS 170A horizontal blanking interval timing 1 24 RS 170A vertical blanking interval 1 25 FCC horizontal blanking interval timing 1 25 FCC vertical blanking interval timing 1 25 Amplitude and Phase measurement
35. ail E 7 2 SLOT 2 num LE 4 21 d ME dU ee 71 A SLOT 3 Video from gt e Analog Input num Board IE Jp Eoi esi ecees SLOT 4 V FILTER E 4 FILTER SLOT ASSIGNMENTS 7 basee C 71 1 NTSC BW LIMIT 510 5 2 IEEE LOW PASS Y 3 CHROMA BANDPASS 4 DIFF STEP FILTER lt lt 5 LF NOISE SS 2 Figure 3 4 Filter switch board A4 block diagram VM700T Video Measurement Set Service Manual 3 15 Theory of Operation CPU Board A5 System Bus The CPU and CPU I O boards are the complete central processing core for the VM700T The CPU board incorporates Flash EPROM program memory nonvolatile memory for data and user programmed routines the front panel interface and the display driver hardware The CPU I O board provides the interface between two RS232 serial ports one parallel printer port and the central processor The CPU board microprocessor runs at 40 MHz A floating point unit FPU processes floating point instructions The microprocessor and the FPU sit on a CPU bus that includes the 32 data lines 32 address lines and control lines from the microprocessor other buses on the CPU board are 8 bits wide Figure 3 5 is a simplified block diagram of the CPU board showing the major funct
36. 15 16 17 18 19 20 21 22 23 24 25 5 8 Change the TV standard parameter from PAL to NTSC by pressing the XY Arrow hard key Change the filter selection from No Filter to NTSC Band Width Limiting Filter by pressing the Move Expand hard key until the filter displays NTSC BW Lim Return the leveled sine wave generator to 50 kHz do not change the output level setting Let the display stabilize Adjust the NTSC BP filter 50 kHz Level adjust on the Filter Switch board so that the change in amplitude Delta Amp is within 0 0246 of the reference level stored in step 4 See Figure 5 1 on page 5 5 for the adjustment locations Reset the leveled sine wave generator for 3 6 MHz do not change the output level setting Let the display stabilize Adjust the NTSC BP Filter Flatness adjust on the Filter Switch board so the change in amplitude Delta Amp is within 0 02 of the reference level stored in step 4 Change the Filter parameter from NTSC BW Lim to Chroma BP by pressing the Move Expand hard key Don t change the settings on the leveled sine wave generator Let the display stabilize Adjust the Chroma Filter Level adjust so that the change in amplitude Delta Amp is within 0 02 of the reference level stored in step 5 Change the TV standard parameter to PAL by pressing the XY Arrow hard key Change the leveled sine wave generator frequency to 4 43 MHz but do not change the out
37. 20 dB to 80 dB 1 0 dB 20 dB to 60 dB Signal to Noise 2 0 dB 60 dB to 70 dB Table 1 34 SCH Phase Measurement SCH Phase Sync Relative Timing Absolute mode accuracy 58 10 ns 59 Burst Relative Phase Table 1 35 TwoField Measurement Range Absolute mode accuracy Field Time Distortion 0 to 35 10 596 Table 1 36 Vertical Blanking Measurement Range Absolute mode accuracy Equalizing Pulse Width 80 ns to 1 us 10 ns Broad Pulse Width 80 ns to 1 us 10 5 Vertical Blanking Field 1 19 lines to 30 lines NA Vertical Blanking Field 2 19 lines to 30 lines NA 1 14 VM700T Video Measurement Set Service Manual Specification Table 1 37 VITS ID Performance Measurement Requirement VITS Recognition Supplemental information Recognizes and displays the name of recognized signals in the vertical interval of both Field 1 and Field 2 lines 15 through 20 VITS test signals recognized are 8 Fields Seq VIRS FCC Multi Burst Pedestal Luminance Bar NTC 7 Combination Sin X X Auto Mode Table 1 38 Line Blanking timing measurements Measurement Range Accuracy Colour Burst Duration 6 cycles to 13 cycles 10 cycles nominal 0 1 cycle Front Porch Duration 0 5 us to 3 hs 1 5 hs nominal 20 ns Line Blanking 9 us to 16 us 12 hs nominal 50 ns Line Sync Rise Time 120 ns to 300 ns 15 ns Fall Time 300 ns to 1 us 30 ns Line Sync 1 4 us to 6 6 us 10 ns 4 7 us nominal Sy
38. 23 24 25 Again to speed up the response to the frequency change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 55 of the reference level stored in step 4 Change the TV Standard parameter from PAL to NTSC by pressing the XY Arrow hardkey Change the filter selection from No Filter to the NTSC bandwidth limiting filter by pressing the Move Expand hardkey until the filter displays NTSC BW Lim Return the leveled sine wave generator to 50 kHz do not change the output level To speed up the response to the frequency change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 5 of the reference level stored in step 4 Reset the leveled sine wave generator for 3 6 MHz do not change the output level To speed up the response to the frequency change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 5 of the reference level stored in step 4 Change the Filter parameter from NTSC BW Lim to Chroma BP by pressing the Move Expand hardkey Don t change the settings on the leveled sine wave generator To speed up the response to the filter change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 5 of the reference level s
39. A second relay selects either the output of or the source 3L 3L to apply to the CH1 CH1 inputs going to the Audio Analog board The relays are selected by the input selection signals Input commons are connected together at the input and applied to the input to the Audio Analog board Filters provide some protection to the Audio Analog board from electromagnetic interference that may accompany the input signal VM700T Video Measurement Set Service Manual Theory of Operation Option 48 GPIB Interface Board 19 Figure 3 17 shows the installed location of the A19 circuit board in a fully optioned instrument The GPIB Interface Board A19 contains a GPIB processor a GPIB controller Dual Port RAM and additional circuity to handle communication between the GPIB processor and the VM 700T processor and communicate with remote devices through the GPIB bus Figure 3 18 shows the functional blocks and bus interconnections of the GPIB board TO ac Do ual A19 GPIB 1l9 0000000000000 Front 00000 00 Interface board ooooooocooooo o 22 Right side of the measurement set Figure 3 17 GPIB board location in the measurement set The GPIB processor tracks the state of the GPIB handles attention messages and performs protocol conversions It is a separate
40. Absolute mode accuracy Relative mode accuracy Luminance Level 0to 700 mV 23 5 mV 0 2 Chrominance Level excluding gray and 0 to 700 mV 1 0 of nominal 0 2 black Chrominance Phase 180 05 0 1 VM700T Video Measurement Set Service Manual 1 11 Specification Table 1 22 Differential Gain and Phase Measurement Differential Gain Minimum Maximum and Peak Differential Phase Minimum Maximum and Peak Relative mode accuracy 0 03 Absolute mode accuracy 0 03 Table 1 23 Frequency Response and Group Delay Measurement Range Absolute mode accuracy Relative mode accuracy Frequency Response to 5 MHz 40 dB 1 0 dB 0 3 dB to 6 MHz 40 dB 12 0 dB 0 6 dB Group Delay to 5 MHz 1 0 us 20 ns 5 ns to 6 MHz 1 0 us 40 ns 10 ns Table 1 24 Horizontal Blanking Measurement Blanking Start Blanking End Blanking Width Table 1 25 Horizontal Timing Measurement Burst Level Horizontal Sync Rise and Fall Time Horizontal Sync Width Burst Width Sync to Burst Start Sync Level 1 12 Absolute mode accuracy 50 ns 50 ns 50 ns 0 1 us to 4 2 us 6 8 us to 12 2 us 6 9 us to 16 4 us Range Absolute mode accuracy 80 mV to 600 mV 1 80 ns to 1 us 10 ns 1 us to 8 us 10 ns 1 4 hs to 3 us 25 ns 5 us to 8 hs 25 ns 75 mV to 600 mV 0 5 VM700T Video Measurement Set Service Manual Specification Table 1 26 Incidental C
41. CPU Diagnostic menu Figure 6 35 as P A or C power up auto reset or custom mode respectively The menu choices for each of the diagnos tics Main Bd CPU Main Bd Display Main Bd Fr Pnl Infc and I O Board are all the same at this point The diagnostic selected determines which is to be interactively run Power Up mode runs the power up diagnostics as at normal power up with an abbreviated go no go test of the circuitry Auto Reset Mode runs all the power up diagnostic tests available for the given diagnostic These Auto Reset tests provide more extensive tests that exercise the circuitry for several seconds at each test The Custom choice permits you to select a single diagnostic test or build a selected set of diagnostic tests to run This mode allows access to any or all of the available low level diagnostic tests Low Level Diagnostic Interface Main Bd CPU Diagnostic Select an OVERALL RUN MODE from the list below Key Selection P POWER UP Mode AUTO RESET Mode C CUSTOM Mode Reprint Q Abort Menu Input your selection Figure 6 35 Low level diagnostic OVERALL RUN MODE menu VM700T Video Measurement Set Service Manual 6 61 Troubleshooting Procedures Custom Run Mode Choices The Custom Mode menu shown in Figure 6 35 permits configuration of the diagnostic testing sequence You can select the Power Up mode the Auto Reset mode or a Custom run mode
42. Calibration DAC The digital signals from the opto isolators are synchronized to the clock signal After the signals are synchronized they go to a counter decoder circuit Two of the signals determine the state of operation diagnostics mode dumping data to the DACS or receiving data from the A D converter The Control Register is a 24 bit register three 8 bit shift registers that holds the control word that controls operating states on the analog board The serial control word is clocked into the shift registers The control bits from the relay control register are buffered by relay drivers to drive the state controlling relays The master oscillator is a integrated circuit oscillator generating a signal at 18 432 MHz The 18 432 MHz signal divided by 3 and reapplied to the A D converter Inside the A D converter the 6 144 MHz input clock is divided by 2 to 3 072 MHz and supplied as an output The 3 072 MHz clock is also provided as an inverted output by the A D converter The 3 072 MHz clock is applied to a multiple divide by two divider where it is divided by 64 to supply the 48 KHz that is the effective sampling rate That 48 kHz is applied to the L R input of the A D converter The 48 kHz and the 3 072 clock are also sent off the analog board The 18 432 MHz signal is also divided by 8 to produce a 2 034 MHz signal used by the digital to analog converters This signal clocks the control word to the control registers
43. Reads the revision bits and checks for range Readable and writeable bits are tested with walking 1 and walking 0 sequences but bits that are read only are tested for resistance to writing Ignored bits are checked to always read 0 Sample dropping If the audio hardware revision number is less than 8 this testis labeled N_A and skipped Otherwise the loopback mode is used to route output data from the DAC into the audio data register The DAC generates long sequences of known values toggling at known intervals These are sampled by the audio data register into DSP shared memory and analyzed by the CPU microprocessor VM700T Video Measurement Set Service Manual 6 97 Troubleshooting Procedures NOTE The Audio Analog board tests require an operating Audio Processor board A12 because they involve synchronized exchanges between a DSP program running on the audio processor microprocessor and an application running on the CPU microprocessor Table 6 12 Audio Analog board diagnostics Test name DAC calibration offset and gain ADC calibration offset and gain Description Self calibrates the ADC and calibrates the output of the DAC againstthe chopper Gain is the ratio of DAC to chopper output Offset is the difference between the signal midpoint ofthe DAC and that of the chopper Checks for completion of the ADC internal self calibration and calibrates the ADC against the chopper Gain is the ratio of acquired signal am
44. See Figure 6 9 b When the screw heads extend through the slotted holes lock the card cage retainer in position by sliding it to the right c Tighten the retaining screws d Install the cover panel refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 17 Maintenance 6 18 Acquisition Memory Board Removal and Replacement As you face the front of the VM 700T in the operating position the Acquisition Memory board A18 is located in a card cage on the right side To remove this board you must first remove the right side cover and the card cage retainer You must also disconnect four cables from the circuit board Required Tools Use the following tools to remove the Acquisition Memory circuit board m Flat blade screwdriver 3 5 or 4 inch blade W Pozidriv screwdriver 1 X Procedure Use the following procedure to remove and replace the Acquisition Memory board 1 Perform the following steps to remove the Acquisition Memory board a Remove the right side cover panel refer to Cover Panel Removal and Replacement on page 6 8 b Remove the card cage retainer refer to step 1 on page 6 16 The Acquisition Memory board occupies the top slot in the right side card cage see Figure 6 10 To remove this board you must first disconnect the ribbon cables shown on the right side of Figure 6 11 d Spread the cable ejector tabs to disconnect each cable
45. TTL 1 200 V 1 Voltage equivalent for levels voltage discharged from a 100 pF capacitor through a 100 resistance Observe the following precautions to avoid damage m Minimize handling of static sensitive components Transport and store static sensitive components or assemblies in their original containers on a metal rail or on conductive foam Label any package that contains static sensitive components or assemblies m Discharge the static voltage from your body by wearing a wrist grounding strap while handling these components m Nothing capable of generating or holding a static charge should be allowed on the work station surface m Keep the component leads shorted together whenever possible Pick up the components by the body never by the leads m Do not slide the components over any surface Servicing static sensitive assemblies or components should be done only at a static free work station Avoid handling components in areas that have a floor or work surface covering capable of generating a static charge Use a soldering iron that is connected to earth ground Use only special antistatic suction or wick type desoldering tools VM700T Video Measurement Set Service Manual Maintenance Customer Service For service parts module exchange returns or technical support in the United States call the Tektronix Customer Service line between 8 00 AM and 5 00 PM Pacific Time Monday through Friday at t
46. Test List Figure 6 32 VM700T diagnostic menus overview cont 6 58 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Low Level Diagnostics Access to the diagnostics menu is available during power up by holding in the Menu front panel button in when the power is turned on Press and hold the Menu button while turning on the power After the VM 700T beeps twice to acknowledge the startup mode release the Menu button The VM 700T then initializes directly into the Low Level diagnostics mode The diagnostic operation begins with the Low Level Diagnostic Interface VM700T Startup Menu shown in Figure 6 33 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu A Calibrate TOUCH PANEL INTERFACE Reprint 8 Abort Menu Input your selection Figure 6 33 VM700T startup menu In the VM700T Startup Menu highlight the D Low Level Diagnostics Menu and press the Select Line button again This displays the Low Level Diagnostics menu shown in Figure 6 34 VM700T Video Measurement Set Service Manual 6 59 Troubleshooting Procedures 6 60 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection LOW LEVEL DIAGNOSTIC
47. These cursors allow precise location of 10 50 and 90 percent points on any transition You can expand the waveform display around any vertical or horizontal point Since the data is digitized the display remains bright at all expansion factors The axes automatically expand with the waveform so all units are correct as displayed The Vector mode provides the normal vectorscope display You can rotate or expand the vectors the rotation angle and gain values are displayed numerically on the screen A unique Find Colorbars feature searches the video signal for color bars and displays the vectors if it finds a color bars test signal You can use the Select Line choice in both Waveform mode and Vector mode to quickly specify any line for display or automatic measurement if an appropriate video test signal is being measured VM700T Video Measurement Set Service Manual Operating Information Measure Mode Measure mode provides graphic displays of measurements such as noise spectrum group delay and K factor for adjustment or closer analysis of the measurement You can make relative to reference measurements against a stored reference to minimize or eliminate signal source errors Signal averaging can be used to reduce the effects of random noise in measurements where averaging is appropriate Picture Mode Picture mode permits you to quickly verify the signal source You can select any line on the picture to view in either the wave
48. acquisition memory controls acquisition patterns Figure 3 8 shows a block diagram for the controller circuitry 32 data lines and the required control and address lines from the system bus are buffered on this board Many of the data and address lines are buffered on the board a second time before being used to drive multiple devices The majority of the control logic and high speed logic functions are incorporated into the controller ASIC application specific integrated circuit The controller now has new functionality for DVM and clamp gating The controller handles CPU interfacing DVM and clamp counter gating control bus routing control DVM counting and some of the buffers that handle data flow Address decoding is handled by the same decoder as for the Acquisition section of the board This block controls the dynamic gains offsets input selections and dither The dither counter is implemented in a PAL and octal D flip flop The output signals from this block are fed directly to the Analog boards in the top compartment of the instrument They perform the following actions W enables the controller board DVM block loads four control registers within the mode control DVM selection blocks m latches 12 as 8 4 bits of data into the calibration DAC located on the analog input board loads 8 bits of data into each register of the bias and clamp level octal DAC located on the analog input board Th
49. begins The RAMP OUT amplified to drive the vertical deflection yoke The vertical height of the display is set by the adjustment of the Vert Size potentiom eter The DC level adjustment of the vertical deflection circuit produces an offset that centers the display vertically Vertical linearity of the raster is adjusted with the Vertical Linearity potentiometer VM700T Video Measurement Set Service Manual 3 29 Theory of Operation 3 30 Horizontal Deflection High Voltage 412 V and 45 V Supply 12 V Brightness Focus Horizontal H Sync Deflection 45V 100V Horiz Horiz Position Horiz Sync Horiz Video Amplifier 550 V Video In Video Out 12 V Contrast Vertical Deflection Vertical V Sync Vertical Vert Position Vert Linearity Vert Hold Vert Size Figure 3 12 Picture Monitor simplified block diagram Blanking Amplifier Blanking between vertical sweeps is produced by the blanking amplifier In the output of the blanking amplifier the BRIGHTNESS adjustment sets the level of CRT beam current between blanking pulses The horizontal deflection circuit provides the drive current to the deflection yoke H Sync is applied a PLL phase locked loop circuit that produces the horizontal deflection signal The frequency of the loop is synchronized to the incoming H Sync signal after setting the correct frequ
50. but none on the CRT continue with these checks 2 Make sure that 12 V is present on pin 7 of the CRT display connector on the back of the display module If 12 V is not present remove the 10 pin drive connector to see if the 12 V comes up If it does the CRT display may be loading the power supply Change to CRT display assembly and check again to see if the display returns 3 With an oscilloscope probe pins 6 horizontal sync 8 video and 9 vertical sync of the CRT display connector for valid drive signals 4 Adjust the brightness and contrast controls on the bottom of the CRT display unit to see if they affect the display For blank screen and lighted POWER SUPPLY FAIL LED symptoms follow this procedure 1 Switch the instrument power off at the rear panel switch 2 Disconnect the CRT 12 V power connector P3 at the power supply and switch instrument power on to see if the display monitor was loading the power supply If the POWER SUPPLY FAIL LED is no longer lit with the 12 V cable disconnected replace the CRT display module VM700T Video Measurement Set Service Manual Troubleshooting Procedures Troubleshooting Option 40 and Option 41 Audio The purpose of the troubleshooting techniques described here is to isolate an audio option fault to one or both of the audio boards You can use the audio diagnostics refer to Audio Option Diagnostics on page 6 97 to help isolate the fault After isolation the
51. is set to 3 81 dBm 2 Connect channel A of the VM700T to the leveled sine wave generator and terminate the channel A loop through output connection in 75 VM700T Video Measurement Set Service Manual Adjustment Procedure 3 Press the Measure hard key and move to the VM700T Diagnostics directory by pressing the Diags soft key if necessary In the Diagnostics directory run the sine wave measurement application by pressing the Measure Sinewave soft key 4 Once the measurement application has initialized turn averaging by pressing the Average hard key until the Average hard key light is on When the display stabilizes press the Freeze hard key The Delta Amp reading should remain at 0 If the Delta Amp reading changes press the Freeze key again as many times as needed until the Delta Amp reading remains at This is now the reference to which all other measurements are compared 5 Setthe leveled sine wave generator for 4 43 MHz do not change the output level setting 6 speed up the response to the frequency change toggle the Average hard key off then back on again after the display has re stabilized 7 Check that the change in amplitude is within 0 5 of the 50 KHz reference level stored in step 4 If the amplitude is in tolerance skip to step 8 If it isn t turn off Averaging so you can see response changes Adjust C57 Mid Frequency on the ADC board to bring the flatness at 4 43 MHz into specifi
52. mately 3 5 V peak just over 2 V rms The positive half and negative half of the differential signal are applied to operational amplifiers that form an instrumentation amplifier This is normally a unity gain stage but it has selectable gain of 10 dB and 20 dB The attenuator preceding can be 0 no attenuation 10 dB or 20 dB The differential input signal is converted to a single ended signal and common mode voltage is suppressed or cancelled 400 Hz Notch Filter DAC Output The signal enters on the left and is applied to the contact arm of a relay that switches the notch filter in or out of the Channel 2 signal path The filter is normally out When the relay is energized the 400 Hz notch filter is inserted in the signal path VM700T Video Measurement Set Service Manual 3 39 Theory of Operation Notch Filter Operation DAC Output The notch filter circuitry has a bandpass filter at 400 Hz The output of the bandpass filter is combined with the input signal The gains are set 2 1 for a resulting output equal to the input signal minus the bandpass circuit output forming a notch at 400 Hz The output of notch filter goes to the A D converter The incoming signal current from the DAC is applied to the summing junction of a high speed operational amplifier This circuit converts the incoming current to a signal voltage and applies it to the CAL side of the NORM CAL relay Calibration Signals There are two calibration signal
53. with the upper 8 bits masked in software DSP X data RAM Same as above DSP Y data RAM Same as above Sign extend buf Checks that the 32 bit data correctly represents 24 bit sign extended data where the up per 8 bits are the same as the sign bit Shared bus timing The 68020 writes a long sequence of data into DSP X memory and reads it During this write and read the DSP runs code that accesses its Y and P memories The test passes if the sequence gets in and out of the memories with no errors Timing is checked for 3 cases 1 Audio interrupts to DSP disabled audio data register not accessed 2 Audio interrupts to DSP enabled audio data register not accessed 3 Audio interrupts to DSP enabled audio data register accessed DSP host port Verifies the major modes ofthe DSP host interface These modes are used in audio ap plication software This test checks the 68020 s ability to initialize the DSP host port tests the host port handshake flag bits and tests data transfer from the 68020 to the DSP through the host port Audio data reg If the audio hardware revision number is less than 8 this testis labeled N A and skipped Otherwise the loopback mode is used to route output data from the DAC into the audio data register This test writes long walking 1 walking 0 sequences to verify each audio data register bit Interrupt reg Checks interrupt register bits Tests the run bit to see if it stops and starts code on the DSP
54. 0 nominal 2T Pulse 0 to 10 Kf 30 3 Kf B1 CCIR Rec 569 K factor 0 Kf nominal Bar Tilt 0 to 40 B2 CCIR Rec 567 End Points 0 nominal Bar Tilt 0 to 40 0 2 2 CCIR Rec 567 P eak to P eak 0 nominal Line Time Distortion 0 to 40 of bar 0 2 CCIR Rec 560 Bar Tilt Rec 569 0 to 40 of bar 0 2 B2 CCIR Rec 569 Field Time Distortion 0 to 35 0 5 Field 9quare Wave Chrominance Luminance 50 0 2 GlorG2 CCIR Rec 569 Intermodulation 0 nominal Luminance Non linear 0 to 5096 0 4 D1 m Rec 569 Distortion 0 nominal VM700T Video Measurement Set Service Manual 1 17 Specification Table 1 44 Low Frequency Error 0 to 25 0 nominal Standard CCIR Rec 569 Measurement Low Frequency Error reported as CCIR LF Error 50 550 Hz LF Error 10 1000 Hz LF Error Table 1 45 Noise measurements Measurement Range Accuracy Standard Unweighted SNR 567 26 dB to 60 dB 1 0 dB Measured on one quiet line per CCIR Rec 567 61 dB to 70 dB 52 0 dB Luminance Weighted SNR 567 26 dB to 60 dB 11 0 dB Measured on one quiet line per CCIR Rec 567 61 dB to 70 dB 52 0 dB Chrominance Weighted SNR 26 dB to 60 dB 1 0 dB Measured on one quiet line per CCIR Rep 637 2 61 dB to 70 dB 52 0 dB Periodic SNR 26 dB to 60 dB 1 0 dB Measured on one quiet line per CCIR Rep 637 2 61 dB to 70 dB 52 0 dB Unweighted SNR 569 26 dB to 60 dB 11 0 dB Measured o
55. 0596 00 200 3634 01 ECM 161 0066 00 011 0102 03 ORDER BY DESC 174 3726 00 070 9647 XX 070 9650 XX MSL 3 VM700T Video Measurement Set Service Manual Replaceable Mechanical Parts Replaceable parts list cont Fig amp index number Serial no Serial no effective Tektronix part number 210 0863 00 343 0136 00 31 161 0066 09 32 161 0066 10 33 161 0066 118 8792 00 174 2740 00 018 0225 00 070 9630 075 0705 119 6589 00 212 0518 00 348 0430 00 407 4893 00 discontd Qty Name amp description WSHR LOOP CLAMP 0 091 ID U W 0 5 W CLP STL CDPL CLAMP LOOP 0 25 ID P LASTIC OPTIONAL ACCESSORIES CA ASSY PWR 3 0 75MM SQ 250V 10A 99 INCH STR IEC320 RCPT EUROPEAN SAFETY CONTROLLED OPTION A1 CA ASSY PWR 3 1 0 MM SQ 250V 10A 2 5 METER STR IEC320 RCPT X 13A FUSED UK PLUG 13A FUSE UNI OPTION A2 CA ASSY PWR 3 1 0MM SQ 250V 10A 2 5 METER STR IEC320 RCPT AUSTRALIA SAFETY CONTROLLED OPTION A3 PRINTER EPSON SERIAL CA ASSY SP ELEC RS 232 4 28 AWG 72 INCH 25 POS FEMALE D SUB X 25 POS MALE D SUB CIRCUIT BD ASSY SERIAL INTERFACE CARD W MANUAL FOR EPSON SERIAL PRINTER MANUAL TECH SERVICE MANUAL VM700T POWER LINE CONDITIONER for use with Option A1 and A2 European and UK Power Cords INSTRUCTION EUROPEAN EMC POWER LINE CONDITIONER VM700T FILTER ASSEMBLY POWER SUPPLY LINE FILTER ADAPTER VM700T SCREW MACHINE 10 32 X 0 312 PNH STL CD
56. 13 Line Voltage 1004 nverter Secondary Switch Rectifier Switching Rectifiers 45 Va Circuit 52Va HV RET Housekeeping Supply HOUSEKEEPING gt 15 12V amp 15V gt 15V Power Primary Regulators Pulse Width Modulator 2 ure 15V RET CURRENT SENSE 15C9 15CS 12CS E SD OVERCURRENT AQ IUNDERVOLTS JOVERVOLTS a PSFAILLED Alarm Logic _ UNDERVOLTS OVERTEMP LED POWER FAIL LINE 9EN9E Tl m POWER OFF 444 V Fan we 42V Drive lt FAN RET Figure 3 13 Simplified block diagram of the power supply 3 32 VM700T Video Measurement Set Service Manual Theory of Operation Input Power Rectifier Input Power Rectifier receives the mains AC voltage and rectifies it to provide the drive power to the inverter switching circuitry A line voltage switch sets the supply to operate on a nominal voltage of either 115 VAC or 230 VAC Input surge current and overvoltage protection components are included in the input rectifier circuit to prevent major component damage in the event that incorrect line voltage is applied to the AC input Housekeeping Power second power supply provides the housekeeping or keep alive power source Supply supply provides power to the logic circuitry that controls the power supply STBY ON logic circuitry One of the sensing signals LINE SENSE to the power supply
57. 5 CPU board block diagram 3 16 Figure 3 6 CPU I O board block diagram 3 18 Figure 3 7 Acquisition circuitry block diagram 3 21 Figure 3 8 Controller section block diagram 3 23 Figure 3 9 Dither generator 64 step dither waveform 3 26 Figure 3 10 Front panel board block diagram 3 27 Figure 3 11 Keypad board A10A2 block diagram 3 28 Figure 3 12 Picture Monitor simplified block diagram 3 30 Figure 3 13 Simplified block diagram of the powersupply 3 32 Figure 3 14 Audio Processor block diagram 3 34 Figure 3 15 Audio Analog block diagram 3 38 Figure 3 16 Audio Analog block diagram 3 44 Figure 3 17 GPIB board location in the measurement set 3 45 Figure 3 18 Simplified block diagram of the GPIB interface option board 3 46 Figure 3 19 GPIB rear panel arrangement 3 47 Figure 3 20 Option 15 block diagram 3 49 VM700T Video Measurement Set Service Manual V Table of Contents Vi Figure 4 1 VM700T Startup Menu Figure 4 2 Instrument run modes menu Figure 4 3 Configure director
58. 8 Gain X X X X X X 27 1 2 VM700T Video Measurement Set Service Manual Filter Slot n for slots 0 X X through 5 Test depends on miscellaneous control logic on the A18 board independent of the hardware components indicated in Figure 6 55 The timing data path depends on the presence of the ADC board but does not rely on the ADC itself being operational 6 83 Troubleshooting Procedures Auto Reset Running All Diagnostics Viewing Stored Diagnostic 6 84 Information If a malfunction causes the VM 700T to reinitialize during normal operation the 700 tries to initialize in Auto Reset mode This mode forces execution of all diagnostics both low level and high level regardless of the state of the Diagnostics Selection file If all diagnostic routines in the Diagnostics Selection file are set to Not Selected or if the Power Up diagnostics are set to Quick Start no high level diagnostics run at power up If the VM700T does not complete system initialization because of a fault the diagnostics are not available to assist in isolating the problem In this case you can force Auto Reset mode to ensure that all diagnostic routines run at power up To force Auto Reset mode perform the following steps 1 Power off the VM 700T Press and hold the Menu button as you turn the power back on After the VM700T beeps twice release the Menu button to display the VM700T Startup Menu see Figure 6 40 o
59. Alarm Logic circuitry can issue a shutdown signal SD to the Pulse Width Modulator PWM to stop the power supply from operating The Alarm Logic circuitry also drives the Over Temp LED and PS Fail LED front panel indicators as feedback to the user of the existing problem Fan Drive separate Fan Drive circuit provides a temperature related drive voltage to the fan As the temperature rises the fan is driven faster to compensate for the rise The temperature sensing element for the voltage control is mounted on the 5 V power supply heat sink VM700T Video Measurement Set Service Manual 3 33 Theory of Operation Option 40 Audio Measurements This section describes the operation of the VM700T Video Measurement Set audio option boards The discussion provides the background information needed for fault isolation to the board level and board replacement it does not include a component level description component level circuit repair is beyond the scope of this manual Audio Processor Board A12 The following paragraphs discuss the Audio processor board Refer to Figure 3 14 as you read the discussion 68020 Data Bus Program X Data Memory Memory 16K 64K 64K Words Words 24 7 gt lt To Audio Analog Board Audio Processor emun jue Interface From Reset Control Register Register Audio Analo Figure 3 14 Audio Processor block diagram 3 34 VM700T Video Measurem
60. BD ASSY KEY A10A2 FOR REPLACE MENT SEE A10 SCREW MACHINE 6 32 X 0 312 PNH STL POZ CIRCUIT BD ASSY FRONT PANEL A10A1 FOR REPLACEMENT SEE A10 SCR ASSEM WSHR 6 32 X 0 312 P NH STL POZ MACHINE BRACKET KEY BD 407 3922 00 amp 337 3662 00 SHIELD ELEC 4 96 CU CLIP ON RIGHT MODULAR SUBASSY W TOUCH PANEL A14 STD MODULAR SUBASSY W TOUCH PANEL OPT 74 PANEL CONDCT ETCHED CONVEX TYPE 0927 SCREW TPG TF 10 16 X 0 5 HEX HD STL ZN PL WASHER FLAT WASHER SHLDR 0 5 DIA W 0 203 DIA ID 0 105 THK STL NI GROMMET PLASTIC GRAY U SHAPE 0 48 ID VM700T Video Measurement Set Service Manual Mfr code 0 ROS TK1907 86928 86928 85471 02697 85471 02697 85471 02697 85471 02697 0 05 80009 73743 78189 9M860 80009 80009 TK0435 TK1163 0 05 93907 0435 93907 80009 30817 80009 80009 80009 3 099 5 400 0588 0 25 Mfr part number 331 0508 06 211 0517 00 ORDER BY DESC ORDER BY DESC 378 0322 00 2 004 803 70 378 0323 00 2 004 803 70 378 0325 00 2 004 803 70 378 0324 00 2 004 803 70 ORDER BY DESC 671 0111 00 12157 50 1202 00 00 0541C 174 1163 01 672 1299 08 672 1299 09 ORDER BY DESC 366 2159 01 333421500 821 12790 024 ORDER BY DESC 821 12790 024 407 4289 00 97 0605 02 X 657 0098 03 657 0099 03 440 3786 01 ORDER BY DESC ORDER BY DESC ORDER BY DESC NA 10 5 Replaceable Mechanical Parts
61. CalDAC adjustment Measure Sinewave and Measure Squarewave described in the Verification and Adjustment sections of this manual In nvramg Executable Files VM700 Diagnostics ADC Acquisition Adc Gain Diagnostic Diagnostic Adjustment AnalogInput Cal Dac Controller Diagnostic Adjustment Diagnostic DiagsLoop FilterBoard GPIB Diagnostic Diagnostic Genlock Measure Measure Diagnostic Sinewave Squarewave Measure Warm Rehoot Video Previous Leave Selection Directory Figure 6 51 High level diagnostics menu 3 Select the soft key of a diagnostic you want to run An initial Diagnostic Menu is shown in Figure 6 52 GPIB is the example Except for the name it is the same for all the high level diagnostic choices 6 74 VM700T Video Measurement Set Service Manual Troupleshooting Procedures NOTE The GPIB diagnostic can be started through the GPIB interface itself execute GPIB Diagnostic but this is not recommended As soon as the GPIB diagnostic starts the interface ceases to talk to the controller To halt the GPIB diagnostic and return to remote control press one of the front panel hard keys Upon exiting the diagnostic the VM700T reboots and an SRQ is asserted A serial poll after the reboot returns the power on status byte 65 There are two run mode choic
62. Check that the Spectrum Cursor 1 amplitude readout is 2 4 to 8 4 dB Check that the Timing p p readout is 1600 to 2600 ps Check that the Alignment p p readout is 1600 to 2600 ps VM700T Video Measurement Set Service Manual 4 31 SDI Option 1 Verification 4 Perform the following steps to check the Jitter application at 270 Mb and 0 5 MHz a Adjust digital television signal generator for a jitter frequency of 0 5 MHz and a jitter amplitude of 1 ns on the signal output b Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 0 5 MHz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 8 4 to 14 4 dB d Check that the Timing p p readout is 800 to 1400 ps e Check that the Alignment p p readout is 800 to 1400 ps 5 Perform the following steps to check the Jitter application at 270 Mb and 5 MHz a Adjust the digital television signal generator for a jitter frequency of 5 MHz and a jitter amplitude of 1 ns on the signal output b Press the VM700T front panel Menu button Touch the Rescale soft key and then touch the Cursors Units soft key d Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 5 MHz as read in the readout e Check that the Spectrum Cursor 1 amplitude readout is 8 4 to 14 4 dB f Check that the Timing p p readout is 700 to 1800
63. Copy button flashes as long as the copy remains in the spooler To delete the copy from the spooler press the Configure button and select the Cancel Copy soft key This soft key only appears when a copy is pending in the spooler To print the spooled copy a suitable printer must be attached to one of the measurement set serial ports or to the parallel printer port You also have to set the Communications configuration file parameters to those needed for the attached printer The action of the control knob depends on its assignment for the current mode of operation For example in Waveform mode rotating the control knob affects horizontal or vertical movement of the display or horizontal or vertical expansion of the display depending on the selections of the Move Expand button and the left right up down button In Auto mode rotating the control knob scrolls through the list of measurements When a user configurable parameter is selected for changing you can rotate the control knob to make the change For informa tion on the specific functions of the control knob in each mode refer to the relevant sections of the user documentation m Display and Graticule Intensity Control To change the intensity of either the display or the graticule hold down the appropriate button Display or Graticule and rotate the control knob VM700T Video Measurement Set Service Manual Operating Information m Select Line Button The Select Line bu
64. Data Buffers When the address buffer is enabled the sequencer static RAM can be read and written by the microprocessor from the data buffer before starting the sequencer VM700T Video Measurement Set Service Manual Theory of Operation Address Register The normal input to static is 16 bits from sequencer address register The four TRIG bits the 16 bit counter CARRY bit and 11 bits out of 32 from the output of static RAM comprise the 16 bit input to the register The TRIG bits are the output of trigger RAM The 11 address bits are the 11 LSBs from the output of the sequencer static RAM that are also fed through an address latch to the dynamic settings static RAM as its normal input nine of these address bits are used in current hardware the other two are reserved for future expansion Static RAM The 32 bit word output of the static RAM memory block goes to a number of circuits when the sequencer is running Eleven bits of the output are fed to an address latch The same 11 bits are also routed to the address register as the program counter Sixteen bits of the output are fed as data to the 16 bit counter while two more bits provide counter control Three other of these bits provide signalling to the acquisition section of the board 16 Bit Counter Sixteen of the 32 bits output by the sequencer static RAM are used as data by the 16 bit counter The two control bits determine the count direction and whether the coun
65. Diagnostic Build a new CUSTOM TEST SEQUENCE by selecting test from those listed Key Selects Unselects Video ASIC Video RAM Video Interrupt Int l Brite DAC Ext l Brite DAC Int l RAM DAC Ext RAM DAC m Reprint 8 Abort Menu Select All Un Sel All Done Selecting Selection s NONE Figure 6 37 Build CUSTOM TEST SEQUENCE menu for display When the menu first appears there are no selections made as indicated in the figure To add a test to the list rotate the large control knob to highlight the choice then press the Select Line button The selected choices are indicated by opening and closing angle brackets around the key letter and shown in the selections list You can select all the choices in the list by highlighting the and selecting it All the choices can be unselected by highlighting the and selecting it After you have made the test selections you want in the custom list highlight the and press Select Line button This also returns to the next higher level menu where the choice to run the tests in the custom list you have just made is available When you run the tests all the selected major test headings and the test results are shown along with the sub test that run as part of the diagnostics You can use the other added choice of editing the current test list if you want to make a change in the custom test list withou
66. Eye Diagram application Table 1 100 SDI Jitter application Table 1 101 SDI Wander application Table 1 102 SDI Interchannel Timing application Table 1 103 SDI Audio Video Timing application Table 1 104 SDI Ch Input Table 1 105 SDI Ch B Input Table 1 106 LTC Input Table 1 107 SDI Output Table 1 108 Analog Ref Input Table 1 109 AES Audio Input Table 1 110 Environmental specification Table 2 1 Audio Option 41 connector pin assignments Table 2 2 Status indicators Table 3 1 Signals used by VM700T RS 232C ports Table 4 1 Test equipment required for verification Table 4 2 Test equipment required for verification procedures Table 4 3 Accuracy and flatness specifications Table 4 4 Example test signals for level and flatness test Table 4 5 Accuracy and flatness specifications Table 4 6 Example test signals for level and flatness test Table 4 7 Test equipment required for Option 1S verification Table 5 1 Test equipment required for verification and adjustment Table 5 2 Gain phase analyzer setup Table 5 3 Gain phase analyzer setup for ADC Table 5 4 Test equipment
67. Frame modes NOTE In the following steps you will check the readout of the Jitter timing and Jitter Alignment measurements Use the value which appears most frequently If two values appear with equal frequency use the larger value If you are using a Tektronix TG2000 Signal Generation Platform with a 1 module you must use Output 2 on the DVG to perform this check 1 Perform the following steps to check the Jitter application at 270 Mb and 50 Hz a 4 30 Connect a 270 Mb 525 line 100 color bars signal to the SDI Ch A input Terminate the SDI Ch A input loopthrough using a 75 high frequency terminator Adjust the digital television signal generator for a jitter frequency of 50 Hz and a jitter amplitude of 2 ns on the signal output Press the 700 front panel Measure button and then touch the SDI Jitter soft key Press the VM700T front panel Menu button Select Rate Frame if necessary using the Rate soft key Select Filter 10 Hz if necessary using the Filter soft key Touch the Cursors Units soft key Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 50 Hz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 2 4 to 8 4 dB Check that the Timing p p readout is 1600 to 2600 ps VM700T Video Measurement Set Service Manual SDI Option 1 Verification 2 Perform
68. PL POZ BUMPER PLASTIC POLYURETHANE BLACK BRACKET ADAPTOR LINE CONDITIONER BOX 0 050 AL VM700T VM700T Video Measurement Set Service Manual Mfr code 85480 5Y 400 2W733 TK2541 80126 80009 80009 80009 80009 TK2548 80009 93907 2K262 TK1943 Mfr part number C191 343 0136 00 ORDER BY DESC ORDER BY DESC ORDER BY DESC 118 8792 00 174 2140 00 018 0225 00 070 9630 XX 075 0705 00 119 6589 00 ORDER BY DESC ORDER BY DESC 407 4893 00 10 13 Replaceable Mechanical Parts Replaceable parts list Fig amp index Tektronix Serial no Serial no number part number effective discontd Qty amp description Mfr code Mfr part number 10 5 1 671 4136 00 B030100 B030209 1 CIRCUIT BD ASSY SDI BD TESTED 389 2417 00 80009 671 4136 00 WIRED VM700T 671 4136 01 8 030210 B030411 1 CIRCUIT BD ASSY SDI BD TESTED 389 2417 00 80009 671 4136 01 WIRED VM700T 671 4136 02 8030412 030849 1 CIRCUIT BD ASSY SDI BD TESTED 389 2417 00 80009 671 4136 02 WIRED VM700T 671 4136 03 B030850 B030919 1 CIRCUIT BD ASSY SDI BD TESTED 389 2417 00 80009 671 4136 03 WIRED VM700T 671 4136 04 8 030920 1 CIRCUIT BD ASSY SDI BD TESTED 389 2417 00 80009 671 4136 04 WIRED VM700T 2 174 3779 00 B030100 1 CA ASSY SP ELEC AQ CONTROLLER 34 32 23633 174 3779 00 AWG 2 6 L RIBBON 2 X 17 HIGH DENSITY RCPT X 2 X 17 HIG 3 174 3850 00 8030100 1 CA ASSY SP ELECTRICAL A
69. Quick Start operation of the VM 700T and is the factory setting for shipment S1 S2 53 54 55 56 57 58 Closed Q Figure 6 50 Normal Boot switch setting Diagnostic LED The diagnostic LED located on the CPU board near the boot switch is used to troubleshoot CPU kernel problems if the VM 700T fails to boot As the boot steps increment the LED number also increments If an error occurs the LED will flash alternately between E and a number That number indicates the failed area of the boot diagnostics A P is displayed when the boot up diagnostics all pass VM700T Video Measurement Set Service Manual 6 73 Troubleshooting Procedures Running the High Level Diagnostics You can run individual user selectable diagnostics on demand either by pressing the Measure button during normal instrument operation or by powering the instrument up with the Measure button held in The high level diagnostic test all run in the same manner To run a specific diagnostic during normal instrument operation do the following steps 1 Press the Measure button 2 Press the Diags soft key The contents of the VM 700T Diagnostics directory are displayed as shown in Figure 6 51 They include the user selectable diagnostics available on power up listed in the Diagnostics Selection file the DiagsLoop routine described later in this section and the routines AdcGain Adjustment
70. Relative Burst Phase Burst Amplitude of sync Burst Amplitude 96 of Bar Range 0 to 3609 0 to 5096 100 180 25 to 200 of Sync 10 to 80 of Bar 10 IRE to 80 IRE when Baris not used Accuracy 0 39 0 4 0 3 0 3 1 0 0 4 0 4 IRE Test signal FCC NTC 7 Composite FCC NTC 7 Composite FCC NTC 7 Composite FCC NTC 7 Composite Horizontal Blanking Horizontal Blanking Sync Amplitude 96 of Bar 2096 to 8096 of Bar 20 IRE to 80 IRE when Baris not used 0 3 0 3 IRE Horizontal Blanking Blanking Level 0 to 9096 of Maximum Carrier 10 290 Horizontal Blanking Sync Variation Blanking Variation 0 to 5096 of Maximum Carrier 0 to 5096 of Bar when Zero Carrier is not used and 0 to 50 IRE when Zero Carrier and Bar are not used 0 to 5096 of Maximum Carrier 0 to 5096 of Bar when Zero Carrier is not used and 0 to 50 IRE when Zero Carrier and Bar are not used Table 1 78 Frequency Response measurements 0 to 9096 of Maximum Carrier 20 to 13096 of Bar Measurement Multiburst Flag Amplitude Multiburst Packet Amplitudes when Zero Carrier is not used and 20 to 130 IRE 0 3 for Zero Carrier 0 3 for Bar and 0 3 IRE for no Zero Carrier and no Bar 0 3 for Zero Carrier 0 3 for Bar and 0 3 IRE for no Zero Carrier and no Bar 0 5 for Zero Carrier no Bar when Zero Carrier and Bar are not used 0 to 100 of Flag 1 of Flag
71. Service Manual Specification Option 1S SDI Specification The specifications for Option 1 are the same as those listed for the VM700T Video Measurement Set except where listed below The following specifications are only valid when Option 1S is installed in a VM700T Table 1 99 SDI Eye Diagram application Characteristic Performance requirement Eye Diagram Measurements Supplemental information Measurements performed on SDI Ch A input signals only Amplitude Accuracy 10 C to 35 C ambient 5 for signals between 600 mVp p and 1 Vp p Full temperature range 10 for signals between 600 mVp and 1 Vp p 20 to 80 Rise Time Accuracy 100 ps for rise times between 400 ps and 1 5 ns Signal Aberrations 5 for 800 mVp p step with 2400 ps rise time Noise Floor Amplitude 10 mV tangential noise Timing 100 ps tangential noise DC Offset Accuracy Filter Performance 10 Hz filter 1 kHz filter VM700T Video Measurement Set Service Manual 10 mV 2 of reading from 1 V to 1 V 3 dB at10 Hz 3 dB at1 kHz 1 37 Specification Table 1 100 SDI Jitter application Characteristic jitter Measurements Maximum Amplitude 143 Mb s Performance requirement Supplemental information Measurements performed on SDI Ch A input signals only 3 ns pk to pk for frequencies of 0 5 MHz and above Max jitter ns 1500 jitter frequency kHz for frequencies below 0 5 MHz 210 Mb
72. Setup Reference Black VIRS Chrominance Reference Amplitude 45 IRE to 160 IRE 80 IRE chroma 0 to 360 1 0 NTC 7 Combination 50 IRE 30 2 IRE NTC 7 Combination 0 to 10 Kf 0 3 Kf FCC 7 Composite 20 to 130 of Bar 0 2 0 5 IRE when VIRS 20 IRE to 130 IRE when is notused Bar is not used 0 to 20096 of burst ampli 1 0 1 when burstis VIRS tude 0 to 8096 of Bar when burstis not used and 0 IRE to 80 IRE when burst and bar are not used not used and 1 IRE when burst and bar are not used VM700T Video Measurement Set Service Manual 1 27 Specification Table 1 83 VIRS measurements cont VIRS Chrominance Phase Relative to Burst VIRS VIRS Luminance Reference 30 to 100 of Bar 0 2 0 2 IRE VIRS 30 IRE to 100 IRE when bar is not used Table 1 84 Signal to Noise Ratio measurements Measurement Range Accuracy Test signal Unified Unweighted SNR 26 dB to 60 dB 1 0 dB Quiet Line 61 dB to 70 dB 2 0 dB Unified Luminance Weighted SNR 26 dB to 60 dB 1 0 dB Quiet Line 61 dB to 70 dB 2 0 dB NTC 7 Unweighted SNR 26 dB to 60 dB 1 0 dB Quiet Line 61 dB to 70 dB 2 0 dB NTC 7 Luminance Weighted SNR 26 dB to 60 dB 1 0 dB Quiet Line 61 dB to 70 dB 52 0 dB Periodic SNR 26 dB to 60 dB 1 0 dB Quiet Line 61 dB to 70 dB 52 0 dB 1 28 VM700T Video Measurement Set Service Manual Specification Audio Option 40 Option 41 and Op
73. Table 6 13 SDI Option 1S diagnostic test descriptions Cont Test name SDI Digital P aths Channel A Signal Lock Channel A Hsync Channel A Data Path Channel B Signal Lock Channel B Hsync Channel B Data Path SDI Eye Path Description This group checks the operation of the digital data paths on the SDI board and consists ofthe following tests Three bits of information are generated by the front end to inform the rest of the system and the software aboutthe status of the incoming signal The first of these indicates that there is a signal present and is generated at 061 19 for Channel A U 162 19 for Channel B The second bit originates at pin 4 of the same part but is read by the software at the other side of U160 for Ch A and U161 for Ch B If both of these bits is asserted high then the diagnostic will conclude that a valid signal is present on the corresponding channel When this is the case the Channel A B Signal Lock test will show pass and the next 2 tests will be performed Otherwise all three tests for that channel will be flagged as N A If a valid signal is detected then the output of U62 3 for Ch 1 or U163 3 for Ch 2 is sampled through a 33 ohm resistor R777 or R820 to determine if the deserializer chip the Gennum 9000 has detected HS YNC errors If so this test FAILS and the data path testis not performed flagged N A If there are no HSYNC errors then the data path test is conduct
74. Verification Procedure Setthe second sine wave generator for 0 02 V 20 mV rms at 3 KHz These two signals add across the termination resistance to produce a 1 kHz signal with a 1 third harmonic distortion d Runthe Audio Analyzer measurement and check for a THD N reading of 0 9 to 1 1 e Move the generator signals to the right channel input and repeat step 2 part d 3 Repeat step 2 for channels B and C substitute the appropriate channel when channel A is called for Check Frequency and Phase Measurement Accuracy This procedure requires an accurate frequency generator or a digital counter to set the frequency The phase measurement requires that both channels have the same signal applied Specifications Checked This procedure checks the following parameters m Frequency accuracy 1 Hz or 0 01 1 digit whichever is worse for inputs of 60 dBu and greater in the frequency range of 20 Hz to 20 kHz m Channel phase difference 1 for inputs of 40 Hz to 20 kHz 2 for inputs of 20 Hz to 40 Hz at levels of 40 dBu and greater Option 41 Frequency 1 Asin Figure 4 9 connect the sine wave generator output to the Audio Accuracy and Channel board 2 Setthe sine wave generator for frequency and amplitude in the specified frequency and amplitude range of the Audio option 20 Hz to 20 kHz amplitude of 60 dBu or greater NOTE Use a test signal level of at least 60 dBu and test at leas
75. address Bits from the control register RUN and STOP can switch the trigger RAM input from data latch output normal operation to address latch output Switching the trigger RAM input to the output of the address latch allows the CPU microprocessor to access the trigger RAM The microprocessor then writes a 4 bit pattern into the trigger RAM through a 4 bit enable buffer The 13 bits 10 bits of data plus over range FRAME and LSYNC are sent to the trigger RAM and and to the data acquisition sections of the board The trigger RAM performs the actual word recognition When the micropro cessor writes an appropriate 4 bit wide pattern into the trigger RAM from a 4 bit enable buffer the four output bits change when certain ranges of input data identified by bit pattern occur The output is four bits of the 16 bit input to the sequencer Input data that could be programmed to trigger sequences may include such things as sync tape dropout or zero carrier pulses Sequencer outputs drive the dynamic settings circuitry and send control bits to the data acquisition board These control bits cause the program counter on the data acquisition board to jump to preset addresses As with the word recognition circuitry the sequencer static RAM is loaded with program information from the CPU microprocessor bit from a control register SRUN enables address and data buffers of the system bus to have access to static RAM Sequencer Address and
76. adjustable gain and adjustable response It has low distortion with 150 output loading and operates between the 5 V and 5 2 V supplies Its low impedance output directly drives the A D Converter An RC compensation network corrects for the small rolloff of the anti aliasing filter at 5 MHz The amplifier includes a limiter that restricts the output voltage to be between 1 V and 1 V to protect the A D converter input from excessive signal levels or power up transients A D Converter A D converter is 12 bit monolithic converter that operates from 14 mega samples per sec to 20 25 megasamples per second It has a dynamic voltage input range of 0 5 V centered around its VREF output The VREF output is held at ground reference by the feedback to the 2 5 V power source so the input voltage range is centered around ground The architecture of the A D converter delays the output by 3 clock cycles The differential clock input of the converter is driven by an ECL source that is capacitively coupled to the clock input The TTL level outputs of the A D converter are divided down to ECL levels through a resistive divider network and applied to buffers A 1 3 V reference for the ECL buffer amplifiers is derived from the A D converter s balanced power supply Buffer buffer is composed of 12 ECL buffers one for each output line from the A D converter They are located close to the A D Converter to minimize loading on the conve
77. after removing the CPU NVRAM or file system NVRAM plug in modules from the CPU board the other is to clear the file system of user files if the VM700T is being transferred to another user or work location The backup battery for the CPU NVRAM and file system NVRAM is on the CPU board If the memory SIMM is removed from the CPU board the stored memory is lost and the memory cells will be in random states Clearing the memory restores factory default settings for the file system and CPU so that the VM700T can be booted up Use the following procedure to clear the CPU NVRAM or the file system NVRAM 1 Access the Utilities menu following the procedure on the preceding page 2 From the Utilities menu see Figure 6 41 use the front panel knob to select N and then press the Select Line button This displays the NVRAM utilities menu with the following two choices F Clear FILE SYSTEM C Clear CPU 3 Use the front panel knob to select F to clear the file system NVRAM or select C to clear the CPU and then press the Select Line button Each NVRAM selection has its own screen explaining what is done and what the resulting state of the file system will be after clearing The Clear File System Utility screen is shown in Figure 6 42 and the Clear CPU Utility screen is shown in Figure 6 43 NOTE If you clear the CPU NVRAM you must recalibrate the touch screen 4 Press the Menu
78. analyzer setups in Table 5 3 Table 5 3 Gain phase analyzer setup for ADC Control Setting A max 8 4 dB Aldiv 30 mdB Function GainP hase Sweep Log Osc Level 300 mVolts Start Freq 100 kHz Stop Freq 20 MHz Marker 5 8 MHz Output Dual Input Ref 75 Q 0 dB Input Test 1 Meg 20 dB 26 Check that the frequency response is flat with 1 division 30 mdB up to 5 8 MHz on the gain phase analyzer VM700T Video Measurement Set Service Manual Adjustment Procedure 27 28 29 30 31 32 33 34 35 36 If the frequency response is not flat within 30 mdB adjust C57 the MID FREQ adjustment and R22 the HIGH FREQ adjustment as needed to obtain the correct response See Figure 5 1 on page 5 5 for the adjustment locations Disconnect both gain phase test cables from the VM700T Connect the sine wave generator and a terminator to the inputs of channel A Set the sine wave generator for a frequency of 43 297 kHz at a level of 3 81 dBm Select Measure mode on the VM700T Then touch the Measure Sinewave soft key The measured reading is the reference used to compare the rest of the measurement to It should be approximately 500 mV peak to peak Set the sine wave generator for a frequency of 4 424959 MHz at a level of 3 82 dBm Check to see that the measured amplitude is within 0 02 of the reference level measured in step 30 If it is not adjust C57 MID FREQUENCY
79. and it operates in one of these modes whenever it is on The manual modes are Waveform Vector Picture and Measure the automatic mode is Auto The power on default mode is Waveform The manual modes perform the specified operation and provide a graphic display with digital readouts and status information Auto mode makes measurements automatically and provides a tabular listing of the measurement results You can get measurement results reported in either mode Parameters such as clamping sync source and the displayed line system line are common for all the manual modes of operation VM700T Video Measurement Set Service Manual Operating Information NOTE Manual mode parameters do not carry over to Auto mode You must set parameters for both the Auto mode and the manual modes The parameter files are reached through the directory and file structure accessed by the Configure button Freeze Source Selection and Average Functions The second row in the keypad contains the Freeze button the input channel selection buttons grouped as SOURCE A B and C and the Average button Freeze Button When you select Freeze signal acquisition is halted The display can be moved expanded or contracted as described below under Control Knob but the display is not updated m Source Selection Button For all operational modes one of the input sources is always selected For some of the manual modes an input source can be inverte
80. application The Measure mode button operation changes so that the measurement choices shown in the Measure menu will be only those relevant to the selected signal source type analog or digital When the 700 is set to Digital Mode the Auto mode button provides direct access to the SDI Format Monitor application VM700T Video Measurement Set Service Manual 2 9 Operating Information Option 15 adds a new soft key to the Measure mode screen and changes the name of one of the existing soft keys The new SDI soft key changes the measurement set to Digital Mode and displays the SDI applications The original Video soft key is renamed to Analog Video The Analog Video soft key changes the measurement set to Analog Mode and displays the analog measurement applications User Programmable Functions Hardcopy Remote Operation You can define a sequence of operations as a new function For example you can create a function that makes the measurements on a transmitter demodulator video output You can label this function DEMOD build it to make all the measurements and provide a printout of the results You can also call another function from within a function to produce a set of measurements You can use a printer that supports PostScript or 24 pin Epson graphics through the standard RS 232C interface to hard copy the on screen information You can used most types of ASCII printers to print the results of Automatic measure ments using
81. board A5 Check the CPU board Diagnostic LED Refer to the diagnostic LED display on page 6 73 Replace the CPU board Refer Removing and Replacing the CPU Board This action requires a complete reprogramming for the replacement CPU Glitches and spikes in Waveform mode VM 700T displays the re initializing message or hangs Faulty ADC board A3 Replace ADC board Refer to Removing and Replacing the ADC Board Faulty acquisition memory Replace the acquisition memory board Refer to board A18 Removing and Replacing the Acquisition Memory Board Faulty analog inputboard Replace the analog input board Refer to Removing and Al Replacing the Analog Input Board Faulty genlock board A2 Replace the genlock board Refer to Removing and Replacing the Genlock Board Faulty ADC board A3 Replace the ADC board Referto Removing and Replacing the ADC Board Faulty acquisition memory Replace the acquisition memory board Refer to 18 Removing and Replacing the Acquisition Memory Board Faulty Flash SIMM onthe Replace the Flash SIMM on the CPU board This will CPU board require a complete reprogramming ofthe CPU board Faulty memory on the Replace the memory SIMM on the CPU board CPU board Faulty CRT touch panel Replace the CRT touch panel Refer to Removing and Replacing the CRT Touch Panel Faulty frontpanel A10A1 Replace front panel keypad board assembly Refer to or keypad board 1104
82. button to clear the selected NVRAM or press any other button to abort the utility VM700T Video Measurement Set Service Manual 6 67 Troubleshooting Procedures Low Level Diagnostic Interface CLEAR FILE SYSTEM UTILITY WARNING Clearing File System NVRAM will destroy 11 user files setups data etc Diagnostic Selection file and the Diagnostic Errors file The instrument will revert to its Default NVRAM File System All diagnostics in the Diagnostics Selection file will be enabled and the Diagnostic Errors file will be deleted Press MENU BUTTON to clear NVRAM any other button to abort Figure 6 42 Clear File System Utility menu Low Level Diagnostic Interface CLEAR CPU NVRAM UTILITY WARNING Clearing CPU NVRAM will destroy TOUCH PANEL INTERFACE calibration Optional Hardware presence status Low Level Diagnostics configuration Low Level Diagnostics Error Log Low Level Diagnostics NVRAM Map The DIAGNOSTICS INTERFACE will revert to its factory default settings and ERROR LOGGING will be disabled until instrument power is cycled or the instrument is otherwise reset Press MENU BUTTON to clear NVRAM any other button to abort Figure 6 43 Clear CPU NVRAM Utility menu Calibrating the Touch 700 is shipped from the factory with its touch screen fully calibrated Screen Although it will seldom be necessary the
83. center support and screw Replace the carrying handle cover and screws CPU Board Removal and As you face the front of the VM 700T in the operating position the CPU board Replacement A5 is located in a card cage on the right side To remove this board you must first remove the right side cover and the card cage retainer You must also disconnect one or more cables from the board The following procedures explain how to remove the CPU board Required Tools Use the following tools to remove the CPU circuit board m Flat blade screwdriver 3 16 or inch blade W Pozidriv screwdriver 1 X VM700T Video Measurement Set Service Manual 6 15 Maintenance Procedure Use the following procedure to remove and replace the CPU board 1 Perform the following steps to remove the right side card cage retainer a Remove the right side cover panel refer to Cover Panel Removal and Replacement on page 6 8 b After removing the right side cover panel loosen but do not remove two screws on the front of the card cage retainer see Figure 6 0 c Slide the retainer carefully to the left until the screw heads clear the slots and then remove the retainer to expose the CPU board for removal 2 Perform the following steps to remove the CPU board a The CPU board occupies the bottom slot of the right side card cage see Figure 6 10 Use the cable ejector tabs on the front panel interconnec tion cable to disconnect that cable
84. chart shown in Table 5 2 3 Disconnect the cable connecting the Analog Input board to the ADC board 1550 to J765 and remove it from the VM700T Table 5 2 Gain phase analyzer setup Control Setting A max 200 mdB 30 mdB Function GainP hase Sweep Log Osc Level 300 mVolts Start Freq 100 kHz Stop Freq 20 MHz Marker 8 MHz Output Dual Input Ref 15 Q 0 dB Input Test 1 Meg 20 dB 4 Connect an SMB to BNC adapter to a 75 Q BNC cable attach a 75 0 feed through termination and connect it to the test channel input connector of the gain phase analyzer 5 Connect a second SMB to BNC adapter to a 75 Q BNC cable and connect the BNC end of the second cable to the dual output connector of the gain phase analyzer 6 Connect the two cable adapters on the ends of the BNC cables together using the cable removed from between the Analog Input and ADC boards Normalize the cables and the gain phase analyzer to remove the cable effects from the measurement see the gain phase analyzer operator s manual for the procedure to normalize the cables 7 Disconnect the SMB cable and the SMB to BNC adapter from the BNC cable going to the output of the gain phase analyzer and connect that cable to the VM700T channel A input terminate channel A with a 75 termina tion VM700T Video Measurement Set Service Manual 5 15 Adjustment Procedure 8 Connect the input of the gain phase analyzer to J
85. choices m The output of the DAC used during diagnostics m The output a high speed solid state switching device This device selects either ground or a high precision 5 V reference and is chopped at 120 Hz The symmetrical square wave developed by the switching is applied to the selected analog input through a coupling capacitor Capacitive coupling shifts the DC level of the signal to 2 5 V When the chop signal is not running the output is at ground Calibration Channel Selection A set of relay contacts determine the channel and side of the differential channel input that the calibration signal is applied to The calibration selections signals drive this set of relays In the unenergized state channel 1 gets the calibration signal The unselected channel is grounded Other relays switch the sense of the calibration signal so that both sides of the balanced differential inputs may be calibrated using the single ended calibration signal During calibration the noninverting input is calibrated first grounding the inverting input When that half is finished the relays switch to apply the calibration signal to the inverting input to calibrate that side Option 40 A D Converter Input Clamp CH 2 and CH 1 Amplifier 3 40 The channel 1 and channel 2 circuits are identical only the channel 2 circuit is discussed here The channel 2 signal is applied to a clamp circuit at the input of the amplifier This clamp circuit protects t
86. d 1032PHS screws Bar nut To 10 32 PHS screws Shallow rack mount 10 32 PH9 Barnut Screws r Rear rack rail Bar nut Figure 6 29 Mounting stationary rack sections VM700T Video Measurement Set Service Manual 6 47 Maintenance Installation Removal from the Rack Rack Adjustments Rack Slide Maintenance Knurled retaining screw Figure 6 30 shows how to install and remove the instrument from the rack After installation the rack slides may bind if they are not properly adjusted To adjust the slides slide the instrument out about 10 inches slightly loosen the screws holding the slides to the front rails and allow them to seek an unbound position Re tighten the screws and check the tracks for smooth operation by sliding the instrument in and out of the rack several times To fasten the instrument securely in the rack tighten the knurled retaining screw The rack slides do not require lubrication The dark gray finish on the rack slides is a permanent lubricated coating To install 1 Pull the intermediate track sections to the fully extended position Q Knurled retaining screw 2 Insertthe instrument chassis sections into the intermediate sections 3 Press the stop latches and push the instrument toward the rack until he latches snap into the holes 4 Again press the stop
87. diagnostic test indicates a hardware problem that requires servicing The VM700T may function for local operation but may be faulty for remote operation if a GPIB Diagnostic test fails Refer to Diagnostic Selection File on page 6 78 to configure the Diagnostic Test Selection file to either run or skip the GPIB diagnostic when running the high level diagnostics The main test titles are as follows VM IPC Register VM Program RAM VM Shared RAM VM Private RAM VM Cen Ctl Reg VM Gpib Chip GP Program RAM GP Shared RAM GP Private RAM GP Spurious Ints GP Int From VM GP Clk Tick Int GP Get Int Each of these main tests have a number of subtests Refer to Appendix B of the VM700T GPIB Interface Programmer Manual for the complete test list if you need to further troubleshoot the GPIB board VM700T Video Measurement Set Service Manual 6 99 Troubleshooting Procedures Troubleshooting Option 15 SDI 6 100 No Signal From the SDI Ch A Input The purpose of the troubleshooting techniques described here is to isolate an SDI option fault to one or both of the SDI boards After isolation the faulty board s may be exchanged to make a repair Before You Troubleshoot If you suspect that Option 1S is not operating properly perform the following steps before you perform the troubleshooting procedures 1 Verify that the VM700T is set to Mode Digital NOTE The VM700T must be set to Mode Digital before you can access any Op
88. each of the rear panel features m Line Voltage and Switching Module The module includes the connector and filter for line input voltage the line fuse and the main power switch m Line Voltage Selector The switch selects either 115 or 230 VAC line input voltage CAUTION If you intend to operate the measurement set from a line voltage other than the voltage configured at the factory you must replace the installed fuse with a fuse of the correct rating See the label on the measurement set rear panel for fuse rating information Operating the measurement set with the wrong fuse can result in severe damage m Exhaust Fan The fan circulates cooling air to internal components The fan opening must be free of obstructions for proper ventilation VM700T Video Measurement Set Service Manual Operating Information m Signal Inputs These are the connections for Channel A B and C signal inputs to the measurement set m External Sync This input allows you to connect the measurement set to an external sync source m RS 232 Ports These ports are the serial interface from the measurement set to a printer for printing displayed data screens and logging information The RS 232 ports also enables you to access the measurement set remotely using a terminal or a PC Refer to the VM 700T RS 232 Interface Programmer Manual for information on configuring the measurement set for remote access and the remote control commands C
89. either channel eye rise fall flags etc This multiplexing is performed by four muxes that are implemented in a PLD U35 Several of these bits are available as inputs to more than one of these 4 muxes The supermux tests exploitthis redundancy For each supermux test we set up the mux selector to route the same bitto as many ofthe flag bits as possible and then we examine the flag bits in the acquired data to verify that the same state is acquired in all the flag bits Even though this description is grouped under one paragraph the tests themselves had to be broken out into separate groups because the diagnostic framework has a time limit forthe completion of each test These groups and the bits checked within each are as follows Fsyncs Checks frame sync A and B on Flags 3 2 1 and 0 Lsyncs Checks line sync A and B on Flags 3 2 1 and 0 Blanking Bits Checks horiz vert blanking bits on Flags 3 2 1 and 0 Eye Flags Checks the eye rise flag on Flags 3 and 2 6 112 VM700T Video Measurement Set Service Manual Options This section provides a brief summary of the available options for the VM700T Video Measurement Set at the time of printing of this manual The Standards options refers to the television standard either Option 01 NTSC or Option 11 PAL for which measurements are made The application options make the appropriate measurements for the installed television standard Standard Options Option 01 and Option 11 When o
90. elsewhere in this manual m Refer to Theory of Operation on page 3 1 for descriptions of the electrical operation of the VM700T Video Measurement Set from a functional circuit block perspective m Refer to Diagrams on page 9 1 for an instrument level block diagram and interconnection diagram m Replaceable Mechanical Parts on page 10 1 for the list of replaceable parts accompanied by exploded view drawings of the instrument VM700T Video Measurement Set Service Manual 6 49 Troubleshooting Procedures Troubleshooting Techniques 6 50 The following procedure is designed to assist in isolating problems which in turn expedites repairs and minimizes down time 1 Ensure that the malfunction actually exists This is done by running the diagnostics to ensure that the instrument is operating as intended by Tektronix Refer to Diagnostics beginning on page 6 55 for a description of the diagnostic tests and information on using diagnostics for troubleshooting module problems 2 Determine and evaluate all trouble symptoms This is accomplished by isolating the problem to a general area such as a replaceable module CAUTION Use extreme care when probing with meter leads or probes because of the high component density and limited access within the instrument The inadvertent movement of leads or a probe could cause a short circuit or transient voltage capable of destroying components 3 Determine the nature o
91. faults requires replacing the faulty module Other faults may be caused by one or more defective system modules In either case the VM 700T diagnostics routines can assist in isolating the fault to field replaceable modules These routines can also evaluate each of the instrument s major hardware components to provide a high degree of confidence that measurement results produced by the instrument are correct The best way to repair multiple module faults is to replace one module at a time checking for correct operation after each replacement until you have located and replaced the faulty module Interconnecting Cables Signals and power supply voltages are passed through the instrument by a system of interconnecting cables The connector holders on these cables have numbers that identify terminal connectors A triangular key symbol is used to identify pin 1 on the circuit board to assist in aligning the correct pins on the mating connector Isolating Operational Faults This section presents a series of operational fault symptoms and suggests corrective actions The most efficient way to use the information involves a two step approach 1 Compare the failure symptoms you are experiencing with the symptoms presented in Table 6 3 2 Run the 700 built in diagnostics routines to assist in isolating the failure Following these steps will assist you in isolating any VM700T fault to a field replaceable module such as a circuit board
92. from the circuit board e Unplug the circuit board using the ejector tab to release the board from the main interconnection board When the circuit board 15 loose slide it out of the card cage 2 Perform the following steps to replace the Acquisition Memory board a Guide the board onto the top right side card cage track and slide it into the card cage connector b Align the circuit board connector pins with the main interconnection board connector and press firmly to seat the connector c Reinstall each of the cables to the Acquisition board ensuring that they are firmly seated in the board connectors see Figure 6 11 d Install the card cage retainer refer to step 4 on page 6 17 e Install the cover panel refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual Maintenance 2 on the A18 Acquisition board J4 on the A18 Acquisition board J1 on the A18 board VM700T top view J3 on the A22 SDI board Opt 1S only J6 on the A18 board Figure 6 11 Acquisition Memory board A18 cables Option 1S SDI Boards The Option 1S hardware consists of an SDI board A22 an SDI Rear Panel Removal and Interface assembly A23 and interconnecting cables As you face the front of Replacement the VM700T in the operating position the SDI board is located in a card cage on the right side To remove thi
93. fuse type and rating specified for this product Avoid Exposed Circuitry Do not touch exposed connections and components when power is present Do Not Operate With Suspected Failures If you suspect there is damage to this product have it inspected by qualified service personnel Do Not Operate in Wet Damp Conditions Do Not Operate in an Explosive Atmosphere Keep Product Surfaces Clean and Dry Provide Proper Ventilation Refer to the manual s installation instructions for details on installing the product so it has proper ventilation VM700T Video Measurement Set Service Manual xiii General Safety Summary xiv Symbols and Terms A A Terms in this Manual These terms may appear in this manual WARNING Warning statements identify conditions or practices that could result in injury or loss of life CAUTION Caution statements identify conditions or practices that could result in damage to this product or other property Terms on the Product These terms may appear on the product DANGER indicates an injury hazard immediately accessible as you read the marking WARNING indicates an injury hazard not immediately accessible as you read the marking CAUTION indicates a hazard to property including the product Symbols on the Product The following symbols may appear on the product A WARNING Protective Ground CAUTION Do Not Use on High Voltage Earth Terminal Refer to Manual 120 V Power
94. in Figure 3 20 is discussed below Digital Signal Path The digital signal path is comprised of the following blocks as shown in Figure 3 20 Equalizer For SDI signals the equalizer actively compensates for the distortions that occur when the SDI signal travels down a length of cable The equalizer amplifies the signal and reshapes the waveform to make the edges fairly distinct Clock Recovery This block is a phase locked loop that creates a regular clock from the irregular data transitions that are contained within the SDI stream Deserializer The deserializer takes the SDI data stream from the equalizer and the clock recovered from the clock recovery circuitry to convert the serialized data into 10 bit parallel data The alignment of the serial data is determined from the embedded TRS marks Since they are the only data patterns where all 10 bits are either zeros or ones they provide a clear indication of how the data words are aligned in the SDI data stream Line and Frame Synthesizer This block examines the 10 bit parallel data stream to identify the TRS marks that indicate line and frame transitions For line transitions the synthesizer sets the line bit according to the H bit in the TRS XYZ word For frame transitions the synthesizer sets the frame bit according to the V bit in the TRS XYZ word The V bit is deglitched by requiring eight consecutive XYZ words four lines with the V bit having the new value before actually set
95. inches 115 6 mm Height 2 67 inches 67 8 mm withoutthe feet attached Weight 2 105 13 5 oz 1 29 kg Shipping weight Approximately 3 lbs 1 36 kg 1 8 VM700T Video Measurement Set Service Manual Specification Table 1 14 Power Line Conditioner Environmental Characteristics Characteristic Temperature Operating Non operating Description 5 C to 50 41 F to 1229 1 30 C 54 F hr max gradient non condensing derated 1 C or 1 8 F per 1 000 ft or305 m above 5 000 ft or 1524 m altitude 20 C to 60 C 4 to 140 F 30 C 54 F hr max gradient Humidity Operating 20 to 80 relative humidity non condensing Max wet bulb temperature 29 4 C or 84 9 F derates relative humidity to 4696 at 40 C or 104 F Non operating 8 to 8096 relative humidity non condensing Max wet bulb temperature 40 or 1049 derates relative humidity to 54 at50 C or 122 F Altitude Operating 2000 meters maximum Non operating Up to 40 000 ft 12 190 m Shake Shock Tektronix Class 5 Random Vibration Non operating Test For Laboratory Benchtop Instruments 10 minutes of vibration in each of the 3 major axes including the following levels 0 0175 g2 Hz from 5 to 100 Hz 3 dB octave from 100 to 200 Hz 0 00875 g2 Hz from 200 to 350 Hz 3 dB octave from 350 to 500 Hz 0 006132 at 500 Hz Overall level of 2 28 GRMS Tektronix Class 5 Random Vibration Operat
96. leave the input unterminated 2 Set the controls of the VAC for NTSC LUM and 700 0 mV 3 On the measurement set press the Measure key the Diags soft key if not already in Diagnostics mode and the Measure Squarewave soft key 4 Check the measurement set for a reading of 700 mV 2 1 mV NOTE If the voltage measured in step 4 is out of the specified limits go to Adjust the Calibration DAC on page 5 9 in the Adjustment Procedure section 5 Move the test signal and select the appropriate channel to repeat the check for channel B and channel C 6 Disconnect the VAC from the measurement set VM700T Video Measurement Set Service Manual 4 7 Performance Verification 4 8 Measure Sinewave This procedure is to be used as a check for proper measurement set system level adjustment It checks the frequency response flatness over the instrument s operating range Test Equipment Required Leveled sine wave generator 75 output impedance output flat within 10 025 dB 0 3 to 6 MHz Example HP 3336C with option 005 Termination 75 precision BNC Tektronix 011 0102 01 or equivalent Coaxial cable 75 high quality noise free 1 meter length Tektronix 012 0074 00 Procedure Measure Sinewave 1 Connect the leveled sine wave generator output to the measurement set channel to be tested start with channel A Terminate the channel loop through output connection in 75 Set the leveled
97. lines 15 through 20 VITS test signals recognized are GCR 8 Fields Seq VIRS FCC Multi Burst Pedestal Luminance Bar NTC 7 Combination Sin X X Table 1 72 Vertical Blanking Measurement Range Absolute mode accuracy Equalizing Pulse Width 80 ns to 1 us 10 ns Serration Pulse Width 80 ns to 1 us 10 ns Auto Mode Table 1 73 RS 170A horizontal blanking interval timing Measurement Color Burst Width Measurement Range Accuracy specifications 6 cycles to 13 cycles 0 1 cycles Horizontal Blanking Front Porch Duration 0 5 us to 2 us Horizontal Blanking Horizontal Blanking Width 6 us to 30 us Horizontal Blanking Horizontal Sync Rise and Fall Time 80 ns to 120 ns 10 to 30 ns Horizontal Blanking 120 ns to 300 ns 20 ns 300 ns to 1 0 us 30 ns Horizontal S ync Width 1 us to 8 us Horizontal Blanking SCH Phase Horizontal Blanking Sync to Setup 5 us to 18 us Horizontal Blanking Sync to Start of Burst 4 us to 8 us 140 ns Horizontal Blanking 0 5 cycles 20 ns 1 24 VM700T Video Measurement Set Service Manual Specification Table 1 74 RS 170A vertical blanking interval Measurement Equalizing Pulse Width Serration Width Vertical Blanking Width Table 1 75 FCC horizontal blanking interval timing Measurement Range Accuracy Test signal Breezeway Width 0 2 us to 3 5 HS 25 ns Color Burst Width 6 cycles to 13 cycles 0 1 cycles Horizontal Blanking Fr
98. logic circuitry is developed from the secondary of the house keeping supply transformer Inverter Switching Circuit This circuitry comprises the Pulse Width Modulator the Switching Transistor Drivers the Switching Transistors and the Secondary Rectifiers and Filters Secondary outputs of the power transformer are full wave rectified and filtered to provide 5 V 5 V 416 5 V and 16 5 V The 16 5 V and 16 5 V are further regulated to produce the 15 V and 15 V supplies to the VM 700T and the 12 V display module power The source voltage for the Fan Drive circuit is also provided by the 12 V supply 12 V and 15 V Regulators 12 V and the and 15 V regulators are similar in operation The 12 V regulator is operating with more head room than the and 15 V regulators and the circuitry is modified to adjust for that difference Each regulator is a combined operational amplifier and FET current pass element with a feedback loop to the operational amplifier from the output voltage Alarm Sensing Alarm Sensing circuitry looks at the various supply voltages to check for undervoltage overvoltage overcurrent and power fail conditions The status of these conditions are the signals fed to the Alarm Logic circuitry Alarm Logic of the alarm sensing outputs is monitored by the Alarm Logic circuitry That circuitry also monitors the temperature sense signals Depending on the state of the sense signals the
99. panel connector at J933 and the ground wire attached to the standoff to remove the Keypad board assembly VM700T Video Measurement Set Service Manual Maintenance Figure 6 21 Removing the retaining screws from the Keypad board 2 Replace the Keypad board assembly by performing step 1 in reverse order orient the connector with its key facing the center of the board see Figure 6 22 Any other connector orientation is incorrect and can cause component failure when the instrument powers on T CAUTION When reinstalling connector J933 on the Keypad board assembly VM700T Video Measurement Set Service Manual 6 35 Maintenance Figure 6 22 Orienting connector J933 for installation on the Keypad board CRT Touch Panel Use the following procedure to remove and replace the CRT touch panel 1 Perform the following steps to remove the CRT touch panel a Remove the CRT bezel refer to CRT Bezel on page 6 32 b Remove the Keypad board assembly refer to Keypad Board Assembly on page 6 34 NOTE It is not necessary to remove the ground wire on the Keypad board assembly if you are removing just the CRT or CRT touch panel c Remove the four nuts that hold the touch panel and then lift the CRT touch panel away from the CRT to remove the touch panel see Figure 6 23 2 Replace the CRT touch panel by performing step 1 in reverse order CRT Assembly Use the following procedure to
100. procedure are given in the example column The examples given are based on the test equipment that many customers and the Tektronix service centers have installed for supporting the VM700 family of video measurement sets Substitute test equipment may be used if available Refer to the Minimum Specification column to determine the key specifications needed to verify the accuracy of the VM700T Video Measurement Set Audio option VM700T Video Measurement Set Service Manual 4 13 Audio Option Verification Procedure Table 4 2 Test equipment required for verification procedures Equipment Minimum specification Purpose Example Sine wave generator Frequency accuracy 30 0196 level flatness 20 Hz to 20 kHz 0 05 dB level accuracy 20 Hz to 20 kHz 0 2 dB residual distortion 0 001096 100 dB Required for all Option 40 and Option 41 verification proce dures TEGAM 565010 two are needed to check distortion measurement accuracy Adapter cable three banana plug to one male XLR 2 re quired XLR connectors must be wired to current AES recommenda tions pin 1 ground pin 2 hot pin 3 cold Connects sine wave generator to adapter cable supplied with VM 700T Option 40 E Z Hook 5023 xx or equivalent Female XLR to male mini XLR adapter cable 2 required Dual female XLR to single male XLR connector Supplied with VM 700T Option 40 XLR connectors must be wired to current AES recommenda t
101. ps g Check that the Alignment p p readout is 700 to 1800 ps 6 Perform the following steps to check the Jitter application at 270 Mb and 9 9 MHz a Adjust the digital television signal generator for a jitter frequency of 9 9 MHz and a jitter amplitude of 1 ns on the signal output b Press the VM700T front panel Menu button Touch the Cursors Units soft key d Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 9 9 MHz as read in the readout e Check that the Spectrum Cursor 1 amplitude readout is 8 4 to 17 4 dB f Check that the Timing p p readout is 700 to 1800 ps g Check that the Alignment p p readout is 700 to 1800 ps 4 32 VM700T Video Measurement Set Service Manual SDI Option 1 Verification 7 Perform the following steps to check the Jitter application at 143 Mb and 3 MHz a e f Replace the 270 Mb signal on the SDI Ch A input with a 143 Mb 525 line NTC7 combination signal Leave the SDI Ch A input terminated with the high frequency terminator Adjust the digital television signal generator for a jitter frequency of 3 MHz and a jitter amplitude of 1 ns on the signal output Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 3 MHz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 14 to 22 dB Check that the Timing p p readout is
102. remove and replace the CRT assembly 1 Perform the following steps to remove the CRT assembly a Remove the CRT bezel refer to CRT Bezel on page 6 32 b Remove the right side card cage retainer refer to step 1 on page 6 16 6 36 VM700T Video Measurement Set Service Manual Maintenance Figure 6 23 Removing the CRT assembly retaining screws c Remove the Keypad board assembly refer to Keypad Board Assembly on page 6 34 NOTE It is not necessary to remove the ground wire on the Keypad board assembly if you are removing just the CRT or CRT touch panel d e g Remove the CRT touch panel refer to the preceding procedure Position the instrument on its right side and remove the four screws holding the CRT assembly to the VM 700T chassis see Figure 6 23 Slide the CRT assembly out of the chassis enough to remove the 10 wire connector at the rear Remove the CRT assembly from the VM 700T chassis and set it aside 2 Replace the CRT touch panel by performing step 1 in reverse order VM700T Video Measurement Set Service Manual 6 37 Maintenance Power Supply Interconnect Board VGA Board and Cooling 6 38 Fan Removal and Replacement This section describes how to remove and replace the power supply the main interconnect board and the cooling fan Required Tools Use the following tools to remove the display and control compo
103. removed 2 Remove the panel by sliding it carefully to the rear of the instrument and out of the grooves in the chassis frame see Figure 6 2 3 Replace the cover panel by guiding it into the chassis grooves sliding it all the way to the front of the instrument and installing the screws Figure 6 2 Removing a cover panel VM700T Video Measurement Set Service Manual Maintenance l O Board Removal and To remove the I O board A20 you must first remove the left side cover panel Replacement and the retainers and screws holding the boards in the card cage Required Tools Use the following tools to remove the I O board m Flat blade screwdriver 3 16 or inch blade W Pozidriv screwdriver 1 X Procedure Use the following procedure to remove and replace the I O board 1 Perform the following steps to remove the I O board a Remove the left side cover panel refer to Cover Panel Removal and Replacement on page 6 8 Remove the retaining screw from the card cage center support and remove the center support from the card cage see Figure 6 3 Remove the circuit board retaining screw from the I O board NOTE It may also be necessary to remove or loosen the circuit board retaining screw immediately above the circuit board you are removing d Unplug the I O board using the ejector tab to release the board from the main interconnection board and remove the board from the card cage
104. required for Option 1S adjustment Table 5 5 SDI Eye Diagram application gain and offset value limits Table 5 6 Jitter application adjustment value limits LL Table 5 7 Cable meter adjustment value limits VM700T Video Measurement Set Service Manual 4 6 4 14 4 15 4 16 4 20 4 21 4 25 5 1 5 15 5 18 5 21 5 23 5 24 5 26 Xi Table of Contents xii Table 6 1 Static susceptibility 6 2 Table 6 2 Audio Option 41 connector pin assignments 6 12 Table 6 3 VM 700T symptoms and corrective actions 6 52 Table 6 4 User selectable diagnostics 6 80 Table 6 5 Diagnostic test number to hardware components tested CROSS referenc san either xe pue d ER ede ears 6 83 Table 6 6 Typical communication setup parameters 6 87 Table 6 7 VM700T RS 232 connector pin outs 6 88 Table 6 8 Typical RS 232C null modem cable wiring 6 89 Table 6 9 Power supply trouble indicators 6 92 Table 6 10 Power supply voltages 6 93 Table 6 11 Audio Processor board diagnostics 6 97 Table 6 12 Audio Analog board diagnostics 6 98 Table 6 13 SDI Option 1S diagnostic test descriptions 6 107 Table
105. respectively The following Camera Testing measurements are available with Option 21 of the VM700T Video Measurement Set measures the color fidelity of a camera s output CCD or tube cameras m Defects identifies defective cells CCD devices CCD cameras only VM700T Video Measurement Set Service Manual 7 1 Options Component Measurements Option 30 m Detail measures the artificial sharpening transitions added to the video in both the horizontal and vertical directions as a percentage of transition amplitude CCD or tube cameras Fixed Pattern Noise identifies unwanted signal non uniformities correlated to CCD cells CCD cameras only m Frequency Response measures the degradation in waveform amplitude as the frequency of modulation increases CCD or tube cameras Measures aliasing components for CCD cameras m Gamma measures the input to output light transfer characteristic of an imaging or display device CCD or tube cameras m Geometry and Registration measures geometric distortions in camera imaging elements CCD or tube cameras m Shading measures variation in camera output luminance levels when light input is constant CCD or tube cameras Vertical Smear measures the camera s ability to handle excess light CCD cameras only Option 30 Component of the VM 700T Video Measurement Set gives you access to the following 12 measurements Bowtie measures timing and
106. s 1 ns pk to pk for frequencies of 1 5 MHz and above Max jitter ns 1500 jitter frequency kHz for frequencies below 1 5 MHz 1 2 ns pk to pk for frequencies of 1 25 MHz and above typical Max jitter ns 1500 jitter frequency kHz for frequencies below 1 25 MHz typical 360 Mb s 0 9 ns pk to pk typical frequencies of 1 33 MHz and above Max jitter ns 1200 jitter frequency kHz for frequencies below 1 33 MHz Frequency Response of J itter Waveform and Spectrum displays 143 Mb s 210 Mb s 360 Mb s Timing amp Alignment itter Readout Accuracy 143 Mb s 270 Mb s 360 Mb s 1 38 3 dB to 0 5 MHz 3 dB to 5 dB at3 MHz 3 dB to 5 MHz 3 dB to 6 dB at 10 MHz 200 ps 2096 of actual for components from 50 Hz to 1 MHz 200 ps 20 3096 of actual for components from 1 MHz to 3 MHz 200 ps 20 of actual for components from 50 Hz to 1 MHz 200 ps 46096 30 of actual for components from 1 MHz to 10 MHz 3 dB at 8 MHz typical 100 ps 5 of actual for components from 50 Hz to 1 MHz typical 100 ps 5 of actual for components from 50 Hz to 1 MHz typical VM700T Video Measurement Set Service Manual Specification Table 1 101 SDI Wander application Characteristic Performance requirement Supplemental information Wander Measurements Measurements performed on SDI Ch A input signals only Frequency Range 143 Mb s 20 ppm 270 Mb s 20 ppm 360 Mb s 20 ppm Frequenc
107. selection 8 Turn the knob to select 270MB 525 line and then touch the Accept Input soft key 9 Touch the Update amp Exit soft key to exit the configuration file ta Figure 5 10 Loosening the right side cover VM700T Video Measurement Set Service Manual Adjustment Procedure Adjustment Procedure Perform the following procedure to adjust the Option 1S hardware NOTE The VM700T and the Option 1S hardware must be warmed up for at least 20 minutes before you perform any adjustments 1 Perform the following steps to adjust the SDI Eye Diagram application gain and offset a b Remove all signal cables and terminators from the Option 1S inputs Press the VM700T front panel Measure button and then touch the Diags soft key Use the front panel knob to scroll through the on screen selections and then touch the SDI Calibration soft key Touch the Eye soft key should be highlighted and then touch the Calibrate soft key Check that the displayed New Data values are within the limits shown in Table 5 5 If the displayed values are within the required limits touch the Accept Data soft key Table 5 5 SDI Eye Diagram application gain and offset value limits Measurement Eye circuit gain Eye sampler offset New data value limits 1 460 to 1 590 40 000 to 105 000 VM700T Video Measurement Set Service Manual 5 23 Adjustment Procedure 5 24 CAUTION The following
108. selection mux Audio sample present Super mux IC Y y To CPU board Acq Ctrlr board Figure 3 20 Option 1S block diagram VM700T Video Measurement Set Service Manual 3 49 Theory of Operation 3 50 Analog Digital The analog digital MUX selects between the Channel A analog data stream and the digital data stream Audio Video MUX The audio video MUX selects between the analog or digital data stream and the audio data stream It also has the capability to insert the external audio data stream in place of the SDI chrominance samples of the data stream for A V timing measurements of external audio Flag Selection MUX The SDI board has many status lines that can be multi plexed onto the six flag lines into the Acquisition Memory board The flag selection MUX controls this mapping Analog Data Path The analog signal path is comprised of the following blocks as shown in Figure 3 20 High Performance Clock Recovery This block performs the same function as the regular clock recovery function block but it has been calibrated and has a far greater jitter tolerance Jitter Demodulator The jitter demodulator converts timing variations in the recovered clock into an analog voltage Various filters can be selected for the output that goes to the 10 bit ADC Analog Peak Detectors This block tracks the analog control voltage from the jitter demodulator The detectors have rapid charging and slow decay
109. separation crosstalk 100 dB 1 20 Hz to 20 kHz Input connectors Option 40 Two mini XLR Switchcraft requires Switchcraft TA3M mini XLR plug Two mini XLR to XLR female adapters and two mini XLR male plugs are supplied Option 41 One male DB 37 connector One DB 37 female connector is supplied Input impedance 50 balanced differential 1 Noise limited source impedance for both channels is lt 600 Multitone Analyzer Specifications Table 1 93 Multitone Analyzer measurement specifications Description Specification Level of Individual Tones R elative to Multitone RMS Level Multitone 1 19 9 dB Multitone 2 18 9 dB Multitone 3 13 8 dB Multitone 4 15 9 dB Reference Frequency for Multitone Recognition Multitone 1 422 Hz Multitone 2 562 Hz Multitone 3 656 Hz Multitone 4 150 Hz Comments VM700T Video Measurement Set Service Manual 1 33 Specification Table 1 93 Multitone Analyzer measurement specifications cont Description Minimum Amplitude of R eference Tone for Multitone Recognition Input Range Window C D E AUTO RANGE Minimum Multitone Recognition Time first time Measurement Update Rate After Recogni tion Maximum Frequency Error for M ultitone Recognition Level Measurement Accuracy Specification Comments 10 dBu 20 dBu 30 dBu 40 dBu 50 dBu 50 dBu 1 second 5 readings per second Within 10 of reference frequency Same as A
110. several data buffers One data buffer holds the interrupts the interrupt enables and the channel data indicator The channel data indicator 1s used to indicate which channel data is held in the audio data register That register is only big enough to hold one sample so it will contain either left channel data or right channel data 1 for left O for right A second data buffer is a read only buffer that holds the board version number Software reads these bits to determine the hardware version installed in the VM700T Other bits held in the data buffers indicate when a calibration is taking place and show which audio option is installed Option 40 or Option 41 VM700T Video Measurement Set Service Manual 3 35 Theory of Operation Reset Register The reset register hold the reset bit as the last bit in the 32 bit interrupt register When the audio processor resets it sets the RESET line low to reset the DSP This line stays low until the audio processor forces it high to start the DSP DSP Processor and l O Interface Oscillator Communication Ports Audio Data Register CPU Access Disable Static RAM 3 36 The DSP is the heart of the Audio Measurement System The DSP has a 16 bit address bus and a 24 bit data bus Devices on the DSP bus include address decoders and buffers used to provides the extra drive needed to drive the memory load 18 memories A buffered oscillator running at 27 5 MHz provides the drive needed
111. signals The SDI Ch B input cannot perform the electrical measurements in the following applications SDI Eye Diagram SDI Jitter and SDI Wander Although you can use this input to measure a signal under test the primary function intended for this input is to enable you to use a digital reference signal to make comparative timing measure ments with the signal under test on the SDI Ch A input The Analog Ref input is a loopthrough BNC input for an analog timing reference signal black burst The remaining loopthrough connector must be terminated in 75 when not used in a loopthrough mode The only function intended for this input is to enable you to compare your analog timing reference signal with a digital timing reference and or a signal under test The timing comparison between an analog reference signal and a serial digital signal will never be a perfect match however you will be able to see resolution to within 1 us The SDI Output is a buffered BNC monitor output that can be set to output one of the following signal sources SDI channel A input SDI channel B input currently selected SDI input channel indicated by front panel LED or none no output You select the signal source in the Source Selection Digital configuration file NOTE You may not be able to use the SDI Output signal effectively as a signal repeater when it is set to output the signal on the SDI channel A input The output of the SDI channel A signal can be in
112. simplified block diagram Figure 9 2 VM700T Video Measurement Set interconnection diagram Figure 10 1 Figure 10 2 Figure 10 3 Figure 10 4 Figure 10 5 Figure 10 6 Front assemblies and power supply Circuit bands 5255 beds thong dd bende Chassis assembly ecs set paren ow hee eta Ps Cabinet and Option 1S creutt boards Circuit board fuse locations Table Input characteristics ccs e Re deca SEN eae Table 1 2 Digitizer 55 eR ee PES Table 1 3 Synchronization yeer eene bere pente ins OEE DERE DEES EAS Table 1 4 Physical characteristics Table 1 5 Power requirements Table 1 6 Environmental specification Table 1 7 Certifications and compliances Table 1 8 Safety standards sisse re rnein EE hb Table 1 9 Safety certification compliance Table 1 10 Rear panel signal connectors Table 1 11 Optional power cords Table 1 12 AC Electrical Characteristics Table 1 13 Power Line Conditioner Mechanical Characteris
113. sine wave generator for 50 kHz at an output level of 500 mV into 75 Q NOTE If the example leveled sine wave generator is being used the output level should be set for 3 81 dBm Press the Measure hardkey then if necessary display the measurement set Diagnostics directory by pressing the Diags soft key In diagnostics run the sine wave measurement application by pressing the Measure Sinewave soft key After the measurement application has initialized turn Averaging on by pressing the Average hardkey until the Average hardkey light is lit When the display stabilizes press the Freeze hardkey The Delta Amp reading should remain at 0 If the Delta Amp reading changes press the Freeze key again as many times as needed until the Delta Amp reading remains at This is now the reference to which all other measurements are compared Set the leveled sine wave generator for a frequency of 4 43 MHz do not change the output level To speed up the response to the frequency change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 5 Delta Amp of 0 5 or less of the 50 KHz reference level stored in step 4 Set the leveled sine wave generator for 5 8 MHz do not change the output level VM700T Video Measurement Set Service Manual Performance Verification 10 11 12 13 14 15 16 17 18 19 20 21 22
114. the frame decoder Phase Locked Loop PLL The PLL takes in a reference clock at the PAL or NTSC line rate frequency and outputs a frequency of 8 times the color subcarrier frequency 8Fsc PLL is not used in 20 25 MHz sampling mode The phase comparator compares the reference clock to the output of the PLL feedback circuit and generates a correction voltage to keep the two synchronized The feedback circuit outputs a window centered on the leading edge of the reference clock If the reference clock falls outside the window the PLL 15 unlocked and the coarse correction circuitry activates to quickly bring the reference clock back into the window The loop filter smooths and integrates the correction voltage which is then used to drive the voltage controlled oscillators VCO Two VCO generate the 8Fsc clock one for PAL and the other for NTSC Control logic enables one VCO at a time The output of the selected VCO is divided to the line rate frequency and fed back to the phase comparator Divide by 2 divide by 2 counter divides the 8Fsc VCO output frequency to four times the Frequency Divider color sub carrier frequency 4Fsc and ensures a 50 duty cycle output Frame Decoder frame decoder examines the composite sync signal from the sync stripper to determine the location of vertical sync The odd field detection modes output a pulse on each odd numbered field The all field detection mode outputs a pulse on every field a
115. the rear panel of the VM 700T The VM 700T is shipped from the factory set for 115 VAC operation If this setting must be changed to 230 VAC simply set the voltage range selection switch to the 230 V position to operate in the high voltage range The 6 A slow blow fuse provides the proper protection in the low voltage range and must be replaced with a 3 A slow blow fuse for operation in the high voltage range NOTE If you wish to use Password protection for your user definable configura tion DIP switch settings on the A5 CPU board must be changed Refer to the VM700T Option 01 NTSC and Option 11 PAL User Manual Configuring the VM700T for a detailed description of how Password operates VM700T Video Measurement Set Service Manual Maintenance Rack Mounting 700 fits in a standard 19 inch rack and is shipped with the necessary hardware for rack mounting Spacing between the front rails of the rack must be at least 17 3 4 inches to allow clearance for the rack slides Rack slides conveniently mount in any rack that has a front to rear rail spacing between 15 1 2 and 28 inches Six inches of clearance between the rear panel of the VM 700T and the rear rack panel is required for connector space and to provide adequate air circulation The rack slides consist of two assemblies one for each side of the rack Each assembly consists of three sections as shown in Figure 6 27 The stationary section of each rack slide a
116. to perform the adjustments to the VM700T Option 15 hardware Table 5 4 Test equipment required for Option 15 adjustment Equipment Minimum specification Example Adjusting the Cable Meter Tektronix TG 2000 Signal Genera and the SDI Eye Diagram tion Platform with a DVG1 module horizontal position Digital television signal 143 Mb 525 line NTC7 combination generator signal 270 Mb 525 line 10096 color bars signal 360 Mb 525 line any television signal Clock generator Wave shape square wave duty factor 40 to 6096 Frequency 67 5 MHz 5 ppm Amplitude 350 to 850 mV p p 20 to 80 rise fall time lt 1 ns Jitter lt 150 ps measured from 10 Hz to 10 MHz Oscilloscope 100 MHz bandwidth Adjusting the 18 MHz refer Tektronix 2465 10 ns div two input channels ence oscillator Clock source 1 MHz Adjusting the 18 MHz refer WWV 1 MHz ence oscillator Cable clone or Simulate 100 meters of Belden 8281 Adjusting the Cable Meter 9C75A37B Cable Clone or 100 meters of cable cable 100 meters of Belden 8281 cable Coaxial cable 3 75 Q impedance high quality noise Signal connections Tektronix part number free 1 meter length Adjusting the Cable Meter 012 0074 00 BNC female to BNC Adjusting the Cable Meter Tektronix part number female connector 2 012 0074 00 Termination 75 Q high frequency 26 dB to 300 Tektronix part number MHz BNC connector 011 0163 00 Alignment tool Non metallic flat blade Adjust potentiomet
117. touch screen can easily be recalibrated To calibrate the touch screen 1 Switch off power to the VM 700T at the front panel 2 Press and hold the Menu button while turning on the power After the VM700T beeps twice to acknowledge the startup mode release the Menu button The VM 700T then initializes directly into the Low Level Diagnos tics Interface with the VM700T startup menu as shown in Figure 6 40 on page 6 66 3 In the startup menu use the large control knob to highlight the T in the Calibrate Touch Panel Interface line 6 68 VM700T Video Measurement Set Service Manual Troubleshooting Procedures 4 Press the Select Line button to make the selection to calibrate The first touch screen calibration instructions are then displayed as shown in Figure 6 44 5 Follow the written directions You can press AUTO to abort the calibration process and returns to the VM 700T startup menu Press any other button to store the setting in NVRAM and brings up the next touch screen calibration menu 6 After you make the adjustment requested and store the current setting a second set of instructions are displayed as shown in Figure 6 45 Follow the directions given in the screen TOUCH PANEL INTERFACE CAL DISPLAY Use the knob to adjust horizontal position and squareness of the screen border lines Press AUTO button to abort or any other to accept and store current setting Current Setting 8 F
118. with shipping tape or an industrial stapler VM700T Video Measurement Set Service Manual 6 5 Maintenance Removal and Replacement Instructions 6 6 AN A Locating the Major Standard Assemblies WARNING This instrument contains hazardous voltages Before removing covers or performing disassembly reassembly procedures always shut off instrument power at the rear panel switch and disconnect the power cord from electrical mains Failure to do this may result in dangerous electrical shock CAUTION To prevent static discharge damage observe the precautions listed in Preventing Electro Static Damage on page 6 2 This section includes removal and replacement procedures for the following assemblies Cover panel page 6 8 m I O board page 6 9 m Option 40 and Option 41 audio boards page 6 11 Option 41 connector installation page 6 12 m Option 48 GPIB Interface board page 6 14 m CPU board page 6 15 B Acquisition Memory board page 6 18 m Option 15 SDI board page 6 19 m Analog Input board page 6 23 m Genlock board page 6 26 m ADC board page 6 28 m Filter Switch board page 6 30 m Display and control components page 6 32 Power supply Interconnect board VGA board and cooling fan page 6 38 As you face the front of the VM 700T in its operating position the CPU A5 is located in the right side card cage along with the Acquisition Memory A18 The I O board and any of the hardware option boards are
119. 0 27 200 3634 01 28 161 0066 00 29 011 0102 03 30 348 0080 01 174 3726 00 070 9647 XX 070 9650 XX 159 0005 00 10 12 Serial no effective B010100 B030100 B010100 B030100 B010100 B030100 B010100 B030100 B010100 B030100 B010100 B030100 Serial no discont d B029999 B029999 B029999 B029999 B029999 B029999 Qty Name amp description Lor gt CABINET COVER RACK MOUNT TOP amp BOTTOM CABINET COVER RACK MOUNT TOP amp BOTTOM SCR ASSEM WSHR 6 32 X 0 312 P NH STL POZ CAB SIDE ASSY LEFT RACK MOUNT CAB SIDE ASSY LEFT RACK MOUNT SCR ASSEM WSHR 6 32 X 0 312 P NH STL POZ CAB SIDE ASSY RIGHT RACK MOUNT CAB SIDE ASSY RIGHT RACK MOUNT SCR ASSEM WSHR 6 32 X 0 312 PNH STL POZ HANDLE CARRYING VM700T SCREW MACHINE 10 32 X 0 5 PNH POZI STAINLESS STEEL PASIVATED THUMBSCREW 10 32 X 1 15 0 375 OD SST RING RETAINING E XTERNAL U O 0 187 DIA SFT WASHER FLAT 0 19 ID X 0 438 OD X 0 031 POLTHN SL SECT DWR EXT 12 625 L W O HARDWARE NUT PL ASSEM WA 8 32 X 0 3445 TL RACK MOUNT SIDE COVER SLIDE DWR EXT 20 0 X 1 69 PAIR R amp L 15 INTER CABINET TOP PORTABLE VM700T SCR ASSEM WSHR 6 32 X 0 312 PNH STL POZ CAB SIDE ASSY RIGHT PORTABLE CAB SIDE ASSY RIGHT PORTABLE SCR ASSEM WSHR 6 32 X 0 312 PNH STL POZ CABINET SIDE LEFT PORTABLE W HANDLE CABINET SIDE LEFT PORTABLE W HANDLE SCR ASSEM WSHR 6 32 X 0 312 PNH ST
120. 0 family of video measurement sets Substitute test equipment may be used if available Refer to the Minimum Specification column to determine the key specifications needed to verify the accuracy of the VM700T Video Measurement Set If you do not have the required test equip ment you can return your instrument to a Tektronix service center for the accuracy verification Table 4 1 Test equipment required for verification Test Equipment Video amplitude calibrator Minimum Specification Purpose Example Square wave 0 0 mV to Reference standard for Tektronix 067 0916 00 not 999 9 mV peak accuracy amplitude verification currently available for 0 0596 resolution 0 1 mV purchase Leveled sine wave generator 75 output impedance output Measure sine wave check Hewlett P ackard 3336C flat within 0 025 dB 0 3 filter flatness Sine wave generator with to 6 MHz option 0052 Telev Telev Coax Termi ision signal generator ision signal generator nation ial cable BNC connectors NTSC full field and burst NTSC test signal source Tektronix TSG 170A or capability accurate to 1 Hz equivalent PAL full field and burst capa PAL test signal source Tektronix TSG 271 or bility accurate to 1 Hz equivalent 75 impedance high quality Signal interconnections Tektronix part number noise free 1 meter length 012 0074 00 75 precision BNC Signal termination Tektronix part number connectors 0
121. 00 159 0145 00 159 0145 00 159 5011 00 159 5011 00 159 5021 00 159 5010 00 159 0145 00 159 0059 00 159 0193 00 159 0194 00 159 0205 00 159 0208 00 159 5011 00 159 5011 00 Name amp description USE 2 0A 125V FAST BLOW 0 1 X 0 1 X 0 24 UL EG CSA CERT USE 2 0A 125V FAST BLOW 0 1 X 0 1 X 0 24 UL EG CSA CERT USE 2 0A 125V FAST BLOW 0 1 X 0 1 X 0 24 UL EG CSA CERT USE 2 0A 125V FAST BLOW 0 1 X 0 1 X 0 24 UL EG CSA CERT USE THRM CHIP SELF RESETTING FUSE 1 25A OLD 2 5A TRIP AT 20 DWG C 15V MAX TGR USE WIRE LEAD 10A 60V FAST BLOW 5 SEC USE WIRE LEAD 15A 32V 10 SECONDS USE WIRE LEAD 15A 32V 10 SECONDS USE THRM CHIP SELF RESETTING FUSE 1 25A OLD 2 5A TRIP AT 20 DWG C 15V MAX TGR USE THRM CHIP SELF RESETTING FUSE 1 25A OLD 2 5A TRIP AT 20 DWG C 15V MAX TGR USE 15A 125V FAST BLOW 0 1 X 0 1 X 0 24 UL EG CSA CERT R451 015 USE SMD 7A 125V FAST BLOW 0 1 X 0 1X 0 24 UL EG CSA CERT USE WIRE LEAD 15A 32V 10 SECONDS USE WIRE LEAD 5A 125V USE WIRE LEAD 10A 60V FAST BLOW 5 SEC USE WIRE LEAD 5A 125V 0 125 SEC F R F R F R F R SE cn rn n n oO mmn mm nm 7m m USE WIRE LEAD 1A 125V 5 SECONDS USE WIRE LEAD 2A 125V 5 SEC SAFETY CON ROLLED USE THRM CHIP SELF RESETTING FUSE 1 25A OLD 2 5A TRIP AT 20 DWG C 15V MAX TGR USE THRM CHIP SELF RESETTING FUSE 1 25A HOLD 2 5A TRIP AT 20 DWG C 15V MAX T amp R m VM700
122. 00T startup menu PANEL CALIBRATION VALUES XSCALE YSCALE 471 XOFFSET 398 YOFFSET 292 231 Press Any Key to Continue Figure 5 6 Panel calibration values 11 If the power on display intensity is not satisfactory adjust the brightness level This adjustment is located on the bottom of the CRT display module NOTE The power up brightness level seldom needs adjustment in normal operation 12 Power off the VM700T and replace all cabinet covers and retaining screws 13 Hold the Auto button in and power on the instrument This runs the full set of diagnostics at power on Check that the instrument passes all diagnostic tests VM700T Video Measurement Set Service Manual 5 13 Adjustment Procedure Extended Adjustment Procedure Adjust the Frequency Response After a board exchange in the analog input section of the instrument the analog system may need readjustment This procedure first checks the overall system response If the verification checks fail the system may need readjustment The adjustments provided are to compensate the system frequency response after a board replacement they are not complete board level adjustments Use the adjustments only as necessary to return the instrument to specification NOTE This procedure requires precision test equipment to make the needed measurements for alignment If you do not have the required test equipment it is recommend that you have the a
123. 0T diagnostics menus overview 6 57 Figure 6 32 VM 700T diagnostic menus overview 6 58 Figure 6 33 VM700T startup menu 6 59 Figure 6 34 Low level diagnostics menu 6 60 Figure 6 35 Low level diagnostic OVERALL RUN MODE menu 6 61 Figure 6 36 Custom run mode menu 6 62 Figure 6 37 Build CUSTOM TEST SEQUENCE menu for display 6 63 Figure 6 38 Front Panel diagnostic selection buttons 6 64 Figure 6 39 Special power up boot modes 6 65 Figure 6 40 700 Startup menu 6 66 Figure 6 41 Diagnostic Utilities menu 6 66 Figure 6 42 Clear File System Utility menu 6 68 Figure 6 43 Clear CPU Utility menu 6 68 Figure 6 44 Touch screen calibration display 6 69 Figure 6 45 Touch screen calibration panel 6 69 Figure 6 46 Panel calibration values 6 70 Figure 6 47 Diagnostic configuration menu 6 70 Figure 6 48 Set diagnostics power up mode menu 6 71 Figure 6 49 Instrument run modes menu 6 72 Figure 6 50 Normal Boot switch setting
124. 0T processor has no means to see or handle interrupts to the GPIB processor LED status indicators for are on the rear panel of the GPIB interface board The LSTN TALK SREQ and CACT controller active bits are all derived from the various control and handshake lines coming from the GPIB controller Figure 3 19 shows the rear panel and status LED arrangement for the circuit board LSTN SREQ LOCK SYS CTL TALK REM CACT Figure 3 19 GPIB rear panel arrangement VM700T Video Measurement Set Service Manual 3 47 Theory of Operation Option 1S Serial Digital Measurements SDI Rear Panel Interface 3 48 Assembly SDI Board Option 1 is composed of three boards SDI Rear Panel Interface assembly the SDI board and a modified Acquisition Memory board The SDI Rear Panel Interface assembly contains the low distortion loopthrough circuitry for both the SDI Channel A and the Analog Reference inputs For the other signal connectors the purpose of the assembly is to provide physical connections for the signals into the measurement set The SDI board contains the analog and digital processing circuitry for the SDI applications The board s purpose is to perform a variety of conversions on the incoming signals so they can be acquired by the Acquisition Memory board The SDI Board is split between a digital signal path and an analog data path The circuit blocks of each data path shown
125. 11 0102 01 1 The example amplitude calibrator requires TEGAM TM500 or TM5000 series power module Theflatness accuracy required of the leveled sine wave generator is only to the bandwidth needed to perform the measurement set verification and adjustments It is not specified to be that flat over the entire bandwidth of the generator 4 6 VM700T Video Measurement Set Service Manual Performance Verification System Verification Procedures Measure Squarewave NOTE If the results yielded by the verification procedures in this section are within the limits specified further adjustment is not necessary and is not recommended Adjusting the measurement set unnecessarily for example to get better reading on a calibration result that is within limits can introduce errors into a functional instrument NOTE This equipment requires a 20 minute warm up period before starting the verification procedures The measurement set must be powered on for at least 20 minutes This procedure checks the amplitude accuracy of the instrument An externally applied precision reference signal is used to check the complete signal path through the measurement set Test Equipment Required m Video amplitude calibration fixture VAC Tektronix 067 0916 00 W Coaxial cable 75 Q high quality noise free 1 meter length Tektronix 012 0074 00 Procedure Measure Squarewave 1 Connectthe VAC to channel A of the measurement set
126. 2 Removing and Replacing the Keypad Board 6 52 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Table 6 3 VM700T symptoms and corrective actions cont Symptom CRT touch panel not oper ating NOTE If the touch panel is not functioning the VM 700T will either display the re initializing message or hang This is not the only problem that can cause this symptom see previous symptom Possible cause Touch panel out of calibra tion Corrective action Try to calibrate the touch panel Faulty CRT touch panel or cabling Replace the CRT touch panel Refer to Removing and Replacing the CRT Touch Panel Loose connections Check connections on back of front panel board Refer to Removing and Replacing the CRT Touch Panel Faulty front panel A10A1 or keypad board A10A2 Replace the front panel keypad board assembly Refer to Removing and Replacing the Keypad Board Faulty display memory module or CPU board Replace the display memory module on the CPU board Replace the CPU board for bad display memory circuit Noise at fixed intervals in Line Spectrum mode Faulty acquisition memory board A18 Replace the acquisition memory board Refer to Removing and Replacing the Acquisition Memory Board RAM test failure Analog gain out of specifi cation OVERTEMP status LED lit POWER FAIL Status LED lit Faulty RAM memor
127. 20 Serial Ports A 32 bit microcontroller is used for the front panel processor built in clock synthesizer generates the required system clock frequency for the front panel processor and the external interface circuitry The front panel is scanned for button presses knob rotation and touch screen touches These inputs are recorded and processed to provide the user control interface to the CPU A simplified block diagram of the CPU I O board is shown in Figure 3 6 This board handles the data flow between the CPU and the two serial RS232C ports and one parallel printer port The parallel printer ports has a dual purpose besides being the printer output port it acts as an input port when used to upload new firmware to the Flash EPROM PD lt 31 0 gt PORTO lt 31 0 gt Serial Port 0 Interface PORT 1 Parallel Port Interface Printer P Connector Address and CPU Data Buffers Bus Control A 32 Bit Counter Figure 3 6 CPU I O board block diagram There are two DB9 RS 232 serial communication ports Of the nine pins in the connector pins 6 and 9 are not connected The remaining pins are in the standard configuration for a DB9 RS 232 DTE serial connector as shown in Table 3 1 VM700T Video Measurement Set Service Manual Theory of Operation Table 3 1 Signals used by VM700T RS 232C ports DCD Data Carrier Detect Required for modem connections only This s
128. 20 mVolts to 880 mVolts 11 Check that Risetime and Falltime readouts are both 400 pSec to 800 pSec 12 Remove all cable and terminators from the VM700T VM700T Video Measurement Set Service Manual 4 35 SDI Option 1 Verification 4 36 VM700T Video Measurement Set Service Manual Adjustment Procedure The procedures in this section may be used if performing the Verification procedures determines readjustment is needed Additionally after a board exchange certain adjustments may be needed to compensate the overall system performance Follow the directions found in the adjustment procedures when readjustment is needed Test Equipment Required The test equipment to use for performing the system level adjustment procedures is shown in Table 5 1 Test equipment suggestions for use in doing the verification procedure are given in the example column The examples given are based on the test equipment that many customers and the Tektronix service centers have installed for supporting the VM700 family of video measurement sets Substitute test equipment may be used if available Refer to the Minimum Specification column to determine the key specifications needed to verify the accuracy of the VM700T Video Measurement Set The specific pieces of equipment required to perform a procedure are shown at the beginning of that procedure Note that the Gain Phase analyzer is required for the extended adjustment procedure on
129. 2C interface If this is successful the test passes All Low High Bits The SDI board can be forced to drive all 10 bits in the data acquisition to low or high via special test modes This group of tests exercises this ability External signals must be connected to both channels in order to have a source of data which is notall low or high so when we force all low or high we can do so under controlled conditions Force Low Data For this test the diagnostic asserts the FORCE LOW signal which is an input to pin 8 on U139 U140 U141 and U43 This causes these devices to drive their outputs to the low state The a data acquisition is done and the acquisition memory checked to make sure that all the bits in the data path are low If they are the test passes Otherwise a fail is flagged and for each non zero bit a message is generated on the console Force High Data The diagnostic forces all data bits from the SDI board to the high state by tri stating the data drivers in PALs U35 and U30 This allows R643 R647 R651 R655 R644 R648 R652 R656 R645 R649 R653 R657 R646 R650 R654 and R658 to pull the data path high After setting up this way the data is acquired and checked to make sure all bits are high If so the test passes Otherwise a test failure is flagged and for each data bit that is not high a message is generated to the console 6 110 VM700T Video Measurement Set Service Manual Troubleshooting Procedures
130. 4 00 13 354 0691 01 14 333 3521 00 15 671 0111 00 16 210 0405 00 17 210 0001 00 18 174 1163 01 19 672 1299 08 672 1299 09 20 212 0040 00 21 366 2159 01 22 333 4215 00 23 211 0658 00 ST eee 25 211 0507 00 2260 dosdesess 27 211 0658 00 28 407 4289 00 29 337 3662 00 30 657 0098 03 657 0099 03 31 Notused 32 440 3786 01 33 213 1014 00 34 210 1454 00 35 210 1456 00 36 348 0085 00 Serial no effective B010100 B010140 Serial no discont d B010139 Qty Name amp description C w CO r3 SCALE CRT FRAME FRONT FINISHED SCREW MACHINE 6 32 X 1 0 PNH STL POZ WASHER LOCK 6 SPLIT 0 031 THK STL CDPL WASHER FLAT 0 15 ID X 0 312 OD X 0 032 STL FILTER AIR F OAM O RING 0 196 OD X 0 070 ID ETHYLENE PROPYLENE FILTER AIR F OAM 2 O RING 0 196 OD X 0 070 ID ETHYLENE PROPYLENE FILTER AIR F OAM 4 O RING 0 196 OD X 0 070 ID ETHYLENE PROPYLENE FILTER AIR F OAM 3 O RING 0 196 OD X 0 070 ID ETHYLENE PROPYLENE PANEL FRONT VM700T ON OFF CIRCUIT BD ASSY ON OFF A16 NUT PLAIN HEX 2 56 X 0 188 BRS CD PL WASHER LOCK 2 INTL 0 013 THK STL CD PL CA ASSY SP ELEC 5 26 AWG 7 7 L RIBBON CIRCUIT BD ASSY FRONT PANEL A10 CIRCUIT BD ASSY FRONT PANEL A10 SCREW MACHINE 8 32 X 0 375 FLH 100 DEG STLPOZ KNOB TV GRAY SCROLL 1 243 ID X 1 4 OD X 0 42 H PANEL FRONT FRONT PANEL LEXAN VM 700T SCR ASSEM WSHR 6 32 X 0 312 P NH STL POZ MACHINE CIRCUIT
131. 40 X 0 25 PNH STL POZ MACHINE CABLE ASSY RF 75 OHM COAX 7 5 L CA ASSY RF COAX RFD 75 OHM RG174 RTANG SMB BOTH SIDES 500HM CIRCUIT BD ASSY GENLOCK A2 CIRCUIT BD ASSY GENLOCK A2 CIRCUIT BD ASSY GENLOCK A2 VM700T Video Measurement Set Service Manual TK0435 TK2469 2K262 80009 80009 93907 TK0435 9M860 TK2469 80009 80009 80009 Mfr part number 672 1413 00 ORDER BY DESC ORDER BY DESC ORDER BY DESC ORDER BY DESC 672 1344 04 672 1344 06 ORDER BY DESC 174 2008 00 ORDER BY DESC 671 3710 00 671 3770 01 821 12790 024 ORDER BY DESC ORDER BY DESC 174 0843 01 672 1460 01 672 1460 02 672 1460 03 10 7 Replaceable Mechanical Parts Replaceable parts list cont Fig amp index Tektronix Serial no Serial no number partnumber effective discontd Qty amp description Mfr code Mfr part number 0 25 PNH STL POZ MACHINE 29 Not used 30 343 1331 02 1 HOLDER PCB CIRCUIT BOARD 5Y400 343 1331 02 RETAINER RIGHT 0 050 ALUM 13 059 X 5 313W 31 211 0507 00 2 SCREW MACHINE 6 32 X 0 312 PNH STL POZ TK0435 ORDER BY DESC 32 Not used 33 671 3922 01 B010100 B010212 1 CIRCUIT BD ASSY ACQUISITION MEMORY A18 80009 671 3922 01 671 3713 00 B010213 B019999 1 CIRCUIT BD ASSY ACQUISITION MEMORY A18 80009 671 3713 00 671 4108 00 B020100 B020230 1 CIRCUIT BD ASSY ACQUISITION MEMORY A18 80009 671 4108 00 671 4108 01 B020231 B031021 1 CIRCUI
132. 5 PNH STL CD PL POZ CA ASSY SP RIBBON GENLOCK HDI 34 32 AWG 10 0 L 2X17 0 05X0 1CTR RCPT CTR PLZBOTH ENDS YAMA CA ASSY SP RIBBON HDI 60 30AWG 10 7 L 2X30 CTR PLZ 0 5X0 1CTR BOTH ENDS YAMAICHI OPTION BOARDS NOT SHOWN CIRCUIT BD ASSY AUDIO PROCESSOR A12 CIRCUIT BD ASSY AUDIO ANALOG A13 CIRCUIT BD ASSY TRIPLE INPUTAUDIO ANALOG A17 CIRCUIT BD ASSY INPUT SELECTOR A17A2 CIRCUIT BD ASSY GPIB A19 VM700T Video Measurement Set Service Manual Mfr code TK0435 80009 TK0435 5Y400 93907 05791 0 25 05791 73743 93907 TK1547 TK1547 80009 80009 80009 80009 Mfr part number ORDER BY DESC 337 3656 00 ORDER BY DESC 337 3739 00 ORDER BY DESC NY 6941 0440 1 375 00 351 0837 00 AL 6941 0440 1 375 22 12157 50 ORDER BY DESC 174 3657 00 174 3616 00 671 1787 05 671 1788 05 672 1348 06 671 2337 00 10 9 Replaceable Mechanical Parts Replaceable parts list cont Fig amp index Tektronix Serial no Serial no number number effective discontd Qty amp description Mfr code part number 10 3 0 441 2113 00 8010100 B019999 1 CHASSIS ASSY VM700T 80009 441 2113 00 441 2113 01 8020100 CHASSIS ASSY VM700T 80009 441 2113 01 1 407 3649 00 B010100 B019999 1 BRKTMTG CRTVM700T 0 260 407 3649 00 407 3649 01 8020100 1 BRKT MTG CRT VM700T TK1943 407 3649 01 2 212 0040 00 2 SCREW MACHINE 8 32 X 0 375 FLH STL POZ TK0435 ORDER BY D
133. 550 on the Analog Input board through the SMB cable SMB to BNC adapter and BNC cable just normalized 9 Bypass the Filter Switch board by removing the cables from J922 and J923 on the Analog Input board and connecting the jumper removed from J924 between J922 pin 2 and J923 pin 2 10 Check that the frequency response for channel is flat within 30 mdB peak to peak one major division on the example test equipment display to 8 MHz NOTE If the frequency response for channel A meets the specification do not make any adjustment to attempt to improve the response curve of channel A 11 If the channel A frequency response is outside the limits specified in step 11 adjust R186 C922 and R555 for a flat response on the analyzer out to 8 018 669 64 Hz see Figure 5 1 on page 5 5 for adjustment locations The following steps describe the procedure a Set R186 and R555 at midrange b Adjust C922 to get the 6 MHz to 10 MHz portion of the response curve centered c Adjust R555 to flatten the response ripple and C922 to control peaking and rolloff of the response curve d Ifthe best result is rolled off adjust R186 to bring the response curve up If the response curve is peaked adjust R186 to roll it off Note that the response is specified only to 8 MHz so it is permissible to have peaking or roll off above 8 MHz to produce a flatter response curve from 0 to 8 MHz 12 Store a reference waveform of the channel A fr
134. 6 13 Notused 14 211 0661 00 15 Not used 16 Not used 17 Not used 18 Not used 19 174 2008 00 20 337 3515 00 21 671 3770 00 671 3770 01 22 211 0658 00 23 211 0661 00 24 174 1165 00 25 174 0843 01 26 672 1460 01 672 1460 02 672 1460 03 27 Notused Serial effective B010100 B010170 B010100 B010109 B010100 B010860 B030532 Serial no discont d B010169 B010108 B010859 B030531 Qty Name amp description fud CIRCUIT BD ASSY ADC A3 CIRCUIT BD ADC A3A1 CIRCUIT BD ASSY ADC FILTER A3A1A1 SCR ASSEM WSHR 4 40 X 0 25 PNH STL POZ MACHINE SCREW MACHINE 4 40 X 0 25 PNH STL CA ASSY SP ELEC 10 26 AWG 6 5 L RIBBON CA ASSY SP ELEC 10 18 AWG 14 05 L RIBBON CIRCUIT BD ASSY FILTER SW A4 CIRCUIT BD ASSY FILTER SW A4 CIRCUIT BD ASSY FILTER SW WO FILTERS A4A1 CIRCUIT BD ASSY CHROMA BANDPASS FILTER A4A1A1 CIRCUIT BD ASSY DIFF STEP FILTER 4 1 2 CIRCUIT BD ASSY LF NOISE FILTER A4A1A3 Mfr code 80009 TK0435 TK0435 9M860 00779 80009 80009 CIRCUIT BD ASSY IEEE LOWPASS FILTER A4A1A4 CRICUIT BD ASSY NTSC BW LIMIT FILTER A4A1A5 SCR ASSEM WSHR 4 40 X 0 25 PNH STL POZ MACHINE CABLE ASSY RF 75 OHM 3 751 0 SHIELD ELEC POLY MIDE CIRCUIT BD ASSY ANALOG INPUT A1 CIRCUIT BD ASSY ANALOG INPUT A1 SCR ASSEM WSHR 6 32 X 0 312 PNH STL POZ MACHINE SCR ASSEM WSHR 4
135. 6 10 6 11 6 13 6 13 6 14 6 16 6 17 6 19 6 21 6 22 6 24 VM700T Video Measurement Set Service Manual Table of Contents Figure 6 15 Removing the attachment screws from the Analog Input board s signal input connector plate 6 25 Figure 6 16 Removing the Genlock 6 27 Figure 6 17 Removing the ADC board 6 29 Figure 6 18 Removing the Filter Switch board 6 31 Figure 6 19 Locating the bezel retaining screws 6 33 Figure 6 20 Disconnecting the STBY ON circuit board 6 34 Figure 6 21 Removing the retaining screws from the Keypad board 6 35 Figure 6 22 Orienting connector J933 for installation on the Keypad 6 36 Figure 6 23 Removing the CRT assembly retaining screws 6 37 Figure 6 24 Removing the power supply retaining screws 6 39 Figure 6 25 Removing the Interconnect board assembly retaining screws 6 41 Figure 6 26 Removing the cooling fan 6 42 Figure 6 27 Construction of rack slides 6 45 Figure 6 28 Rail detail for mounting rack slides 6 46 Figure 6 29 Mounting stationary rack sections 6 47 Figure 6 30 Installing and removing the VM700T from the rack 6 48 Figure 6 31 VM 70
136. 60 119 2616 02 21 212 0010 00 4 SCREW MACHINE 8 32 X 0 625 PNH STL POZ TK0435 ORDER BY DESC 22 210 0458 00 4 NUT PL ASSEM WA 8 32 X 0 344 STL 73893 ORDER BY DESC 23 348 0014 00 4 FOOT CABINET BLACK PHENOLIC 0 75 ORDER BY DESC 24 212 0010 00 4 SCREWMACHINE 8 32X 0 625 PNH STLPOZ TK0435 ORDER BY DESC 25 348 0276 01 6 SHLD GSKT ELEK MESH TYPE 0 124 0D 7 442 80009 348 0276 01 26 252 0571 00 1 NEOPRENE EXTR CHAN 0 234X 0 156 85471 ORDER BY DESC 27 348 0150 00 1 GROMMETPLASTIC DK GRAYU SHAPE 0 661D OKBZ5 NA 28 351 0602 00 10 GUIDE CKT BOARD MAIN CHASSIS POLYAMIDE 80009 351 0602 00 29 351 0752 00 8 GUIDE LIGHT ACRYLIC GRATICULE TK1908 PER TEK DRAWING 30 407 3687 00 1 BRACKET AIR ALUMINUM 80009 407 3687 00 31 211 0507 00 1 SCREWMACHINE 6 32X 0 312 PNH STLPOZ TK0435 ORDER BY DESC 32 351 0817 00 5 GUIDE CKT BD NYLON 6 0 L 32559 DC 600 33 348 0089 00 3 BUMPER PLASTIC 0 312 DIA X 0 855 L BLACK 0 R05 348 0089 00 VINYL 34 426 2221 06 1 FRAME ASSEMBLY VM700T 80009 426 2221 06 35 333 4214 00 1 PANELREAR REAR PANEL 0 062 ALUM VM700T 1943 333421400 36 211 0507 00 6 5 6 32 X 0 312 P NH STL POZ TK0435 ORDER BY DESC 37 671 3976 00 1 VGA CONNECTOR ASSEMBLY A21 80009 671 3976 00 38 214 3903 01 2 SCREW JACK 4 40 X 0 312 EXT THD 4 40 INT 0 01 214 3903 01 THD 0 188 HEX STL 10 10 VM700T Measurement Set Service Manual Replaceable Mechanical Parts Replaceable parts list
137. 7 1 Optional accessories 7 5 Table 7 2 Optional power cords 7 6 VM700T Video Measurement Set Service Manual YS General Safety Summary To Avoid Fire or Personal Injury Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it To avoid potential hazards use this product only as specified Only qualified personnel should perform service procedures To avoid potential hazards use this product only as specified Use Proper Power Cord Use only the power cord specified for this product and certified for the country of use Use Proper Voltage Setting Before applying power ensure that the line selector is in the proper position for the power source being used Ground the Product This product is grounded through the grounding conductor of the power cord To avoid electric shock the grounding conductor must be connected to earth ground Before making connections to the input or output terminals of the product ensure that the product is properly grounded Observe All Terminal Ratings To avoid fire or shock hazard observe all ratings and markings on the product Consult the product manual for further ratings information before making connections to the product Do Not Operate Without Covers Do not operate this product with covers or panels removed Use Proper Fuse Use only the
138. 700 to 1400 ps Check that the Alignment p p readout is 700 to 1400 ps 8 Perform the following steps to check the Jitter application at 360 Mb and 15 kHz a c d Replace the 143 Mb signal on the SDI Ch A input with a 360 Mb 525 line 10 step signal Leave the SDI Ch A input terminated with the high frequency terminator Adjust the digital television signal generator for a jitter frequency of 15 kHz and a jitter amplitude of 2 ns on the signal output Check that the Timing p p readout is 1600 to 2600 ps Check that the Alignment p p readout is 1600 to 2600 ps 9 Perform the following steps to check the Jitter application at 360 Mb and 9 9 MHz a Adjust the digital television signal generator for a jitter frequency of 9 9 MHz and a jitter amplitude of 0 7 ns on the signal output Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 9 9 MHz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 9 to 18 dB Check that the Timing p p readout is 490 to 1320 ps Check that the Alignment p p readout is 490 to 1320 ps VM700T Video Measurement Set Service Manual 4 33 SDI Option 1 Verification Interchannel Timing Application 4 34 Perform the following procedure to check the SDI Interchannel Timing application 1 Perform the following steps to check the digital to analog mode of the SDI Interchannel
139. 70764200 BOULDER CO 80301 WESTFIELD PA 16950 LAKEWOOD OH 44107 4101 GRANTS PASS OR 97526 COLD SPRINGS KY 41076 INDIANAPOLIS IN 46239 KENILWORTH NJ 07033 1721 MILFORD IL 60953 VANCOUVER WA 98662 HILLSBORO OR 97123 CHICAGO IL 60609 DES PLAINES IL 60016 3049 SPOKANE WA 99204 KLAMATH FALLS OR 97601 PORTLAND OR 972143574 MT CLEMENS MI 48045 TUALATIN OR 97062 10 3 Replaceable Mechanical Parts Manufacturers cross index cont Mfr code Manufacturer 0 05 NORTH STAR NAMEPLATE INC 30817 INSTRUMENT SPECIALTIES CO INC 34641 INSTRUMENT SPECIALTIES CO INC TK1943 NEILSEN MANUFACTURING INC 06383 PANDUIT CORP 80126 PACIFIC ELECTRICORD CO TK1163 POLYCAST INC TK1908 PLASTIC MOLDED PRODUCT INC 02697 PARKER HANNIFIN CORP 3M099 PORTLAND SCREW COMPANY 0 25 Q amp D PLASTICS INC 06090 RAYCHEM CORP 23633 RICHEY ELECTRONICS INC 78189 SHAKEPROOF 86928 SEASTROM MFG CO INC 0 01 STAUFFER SUPPLY CO 060D9 UNITREK CORPORATION TK0588 UNIVERSAL PRECISION PRODUCT TK2469 UNITREK CORPORATION 80009 TEKTRONIX INC 0J R05 TRIQUEST PRECISION PLASTICS 5Y400 TRIAX METAL PRODUCTS INC 19136 WALDES TRUARC INC TK2548 XEROX CORPORATION 61857 SAN O INDUSTRIAL CORP 10 4 Address 5750 NE MOORE COURT EXIT 53 RT 80 BOXA 1111 STANLEY DR PO BOX 365 3501 PORTLAND RD NE 17303 RIDGELAND AVE 741 WEST REDONDO BEACH BOX 10 9898 SW TIGARD ST 4336 5 ADAMS 2360 PALUMBO DR P
140. 8 01 05 07 2001 1 CIRCUIT BD ASSY MOTHER A11 80009 672 1298 01 1 CIRCUIT BD ASSY BUS INTERCONNECT A11A1 1 CIRCUIT BD ASSY MAIN INTERFACE RIGHT A11A2 1 CIRCUIT BD ASSY MAIN INTERFACE LEFT A11A3 47 211 0661 00 6 SCR ASSEM 4 40 X TK0435 ORDER BY DESC 0 25 PNH STL POZ MACHINE 48 Not used 49 Not used 50 Not used 51 Notused 52 337 3658 00 1 9HIELD ELEC RIGHTALUMINUM 80009 337 3658 00 10 8 VM700T Video Measurement Set Service Manual Replaceable Mechanical Parts Replaceable parts list cont Fig amp index number 53 54 55 56 57 58 59 60 61 62 63 64 65 Tektronix part number 211 0507 00 337 3656 00 211 0507 00 Notused 337 3739 00 211 0101 00 361 1590 00 351 0837 00 361 1591 00 210 0405 00 211 0001 00 174 3657 00 174 3616 00 671 1787 05 671 1788 05 672 1348 06 671 2337 00 Serial no effective Serial no discont d Qty Name amp description 4 1 6 SCREW MACHINE 6 32 X 0 312 PNH STL POZ SHIELD ELEC LEFT ALUMIMUM SCREW MACHINE 6 32 X 0 312 PNH STL POZ SHIELD ELEC FILTER BOARD SCREW MACHINE 4 40 X 0 25 FLH 100 DEG STL CD PL POZ SPACER STANDOFF 0 250 DIA X 1 375 L W 4 40 X 0 250 DP TAPPED HOLE BOTH ENDS NYLON GUIDE CKT BD 3 935 X 1 35 X 0 55 PLASTIC SPACER STANDOFF 0 250 DIA X 1 375 L W 4 40 X 0 250DP TAPPED HOLE BOTH ENDS ALUMINUM W GOLD FINIS NUT PLAIN HEX 2 56 X 0 188 BRS CD PL SCREW MACHINE 2 56 X 0 2
141. AUTION Peripheral equipment operating on ac mains voltages must be properly grounded to prevent applying a floating voltage to the measurement set internal circuitry that can cause damage m Parallel Printer Port You can use this port to connect the measurement set to a Centronics compatible parallel printer Uploading firmware upgrades is also done through the printer port The firmware and uploading program are distributed on disk and uploaded from a personal computer through the parallel printer port You will need a computer to computer data cable for example and XT compatible LapLink cable to make the connection for uploading m VGA Output You can view the measurement set display on a standard monitor connected to the output connector Thesignal inputs and the external sync connector are loop through connections that must be terminated in 75O when they are not used Three 75Q terminations are provided as standard accessories VM700T Video Measurement Set Service Manual 2 17 Operating Information Equipment Video Signal Sources Required Most measurements supported by the measurement set are made using television video signals The video signals can be from either off the air broadcast or looped through programming signals connected to the rear panel Channel and External Sync inputs see Figure 2 11 Non loop through signals must have the signal output terminated with precision 75 2 termination three of whi
142. Absolute mode accuracy 10to 80 IRE 10 590 80 ns to 1 us 10 ns 3 us to 7 us 10 ns Burst Width 6 cycles to 13 cycles 0 1 cycle FCC 0 5 cycle RS 170A Sync to Burst Start RS 170A 4 us to 10 us 150 ns Sync to Burst End FCC 4 us to 10 us 25 ns VM700T Video Measurement Set Service Manual 1 21 Specification Table 1 59 Horizontal Timing cont Measurement Absolute mode accuracy Front Porch 0 1 hs to 3 5 us 10 ns FCC 10 ns RS 170A Sync to Setup 8 8 us to 13 0 us 10 ns Breezeway FCC 0 1 us to 5 us 25 ns Sync Level 20 IRE to 80 IRE 10 596 Table 1 60 Incidental Carrier Phase Modulation Measurement Range ICPM requires zero Carrier Pulse and the quadrature output of the demodulator on Channel C Table 1 61 Jitter J itter 2 Field 20 us J itter Long Time 20 us Table 1 62 K Factor Measurement Range 2T Pulse K Factor 0 to 10 Kf 10 to 5 Kpg Pulse to Bar Ratio 10 to 125 Pulse Half Amplitude Duration HAD 100 ns to 500 ns Table 1 63 Level Meter Absolute mode accuracy 1 0 Absolute mode 10 ns 10 ns Absolute mode accuracy 0 3 0 3 0 7 5 ns Measurement Absolute mode accuracy Level Meter 00141 35 Table 1 64 Line Frequency Measurement Range Absolute mode accuracy Line Frequency 3 0 1 Field Frequency 3 0 1 1 22 VM700T Video Measurement Set Service
143. Board A1 Loop Through Inputs Mode Control Clamped Input Amplifiers Clamp and Bias Generator Channel Selection The analog input board performs input selection and applies bias clamping offset gain and dither to the input video before digital conversion This board also contains a calibration DAC digital to analog converter that is automati cally switched into the signal path to ensure accuracy A block diagram of the module is shown in Figure 3 1 The three video channels and the external sync signals have independent high impedance loop through inputs The clamped input amplifiers are high input impedance devices to minimize loading of the loop through signals The mode control block passes or decodes instructions from the acquisition con troller board These instructions control the clamped amplifiers sync selection channel selection calibration DAC cal relay operation and the DVM selection The clamped input amplifiers there are three one for each channel can either DC couple or DC restore clamp the video signal Clamping is applied before channel selection to allow independent clamping of video signals that are synchronous but mis timed relative to each other The bias level for each channel is summed with the buffered video just before clamping The clamp and bias generator supplies the analog clamp and bias voltages to each clamped input amplifier Three dual DAC devices are used to provide the six outputs us
144. CREW MACHINE 6 32 X 0 312 PNH STL POZ TK0435 NUT PLAIN HEX 8 32 X 0 312 885 CD PL NUT PLASSEM WA 8 32 X 0 344 5 CD PL SCR ASSEM WSHR 8 32 X 0 500 PNH STL 0 01 CDPLT 20TORX DR MACHINE PLUG BUTTON 0 156THK X 0 375 DIA BLACK 28520 NYLON SHIELD ELEC CABLE 5Y400 SCR ASSEM WSHR 4 40 X TK0435 0 25 PNH STL POZ MACHINE BRACKET ELEC 407 3780 01 333 3532 00 337 366 80009 9 00 337 3670 00 ASSEMBLED SCREW MACHINE 6 32 X 0 250 PNH STL POZ TK0435 SHIELD ELEC CLIP ON CU BE 5 25 L 34641 SHIELD ELEC CLIP ON CU BE 9 0 L 34641 SHIELD ELEC BE CU CLIP 1 2 80009 SHLD GSKT ELE FINGER TYPE W MAGNEFIL 30817 ADHESIVE 6L X 0 343 BECU BRIGHT FINISH SCREW MACHINE 6 32 X 0 875 PNH STL CD 93907 PLPOZ VM700T Video Measurement Set Service Manual Mfr part number ORDER BY DESC ORDER BY DESC C8090 632 24 671 1922 02 441 1814 01 331 3972 00 ORDER BY DESC 97 0605 02 X 97 0605 02 X 174 0844 01 ORDER BY DESC ORDER BY DESC 343 0088 00 119 4258 04 ORDER BY DESC ORDER BY DESC 3059 ORDER BY DESC ORDER BY DESC 407 4290 00 ORDER BY DESC 337 3670 00 337 3669 00 337 3532 00 0097 0510 02 ORDER BY DESC Replaceable Mechanical Parts Replaceable parts list cont Fig amp index Tektronix number number 10 2 1 672 1473 00 2 211 0661 00 3 Not used 4 Notused 5 Notused 6 Notused 7 Notused 8 Notused 9 211 0008 00 10 174 1164 00 11 174 0837 00 12 672 1344 04 672 1344 0
145. CS POWERUP MODE Select a Powerup Mode from the list below The mode selected will be stored in Diag NVRAM and will be effective for NORMAL powerups ie Boot Switches in NORMAL position The current Powerup Mode setting is STARTUP MENU Key Selection 0 QUICK Skip Diagnostics start Instrument STARTUP MENU s n Goto VM700T Startup Menu P POWERUP 5 Do Diagnostics start Instrument L LOW LEVEL DIAGS 100 Loop on Low Level Diagnostics D HIGH LEVEL DEBUG reni or d Run Instrument in DEBUG MODE Reprint Abort Menu Input your selection Figure 6 48 Set diagnostics power up mode menu Bypassing the Boot Switch Power Up Mode The boot switch can be set to start in various power up modes for Factory Service use in troubleshooting and testing There is a diagnostic menu in the Low Level Diagnostic Interface select P in Figure 6 48 that can be used to override the boot switch setting for starting up the instrument from that menu That menu is the Instrument Run Modes Menu shown in Figure 6 49 Under normal operation the boot switch settings will remain in the factory default positions for shipment and the Instrument Runs Modes menu is not needed to override the boot switch VM700T Video Measurement Set Service Manual 6 71 Troubleshooting Procedures Low Level Diagnostic Interface knob moves cursor Select Line inputs
146. ESC 3 211 0507 00 3 SCREW MACHINE 6 32 X 0 312 PNH STL POZ TK0435 ORDER BY DESC 4 426 1629 04 1 FRAME CABINETOPENFR 8 75FULL 80009 426 1629 04 RACK FINISHEDVM700T 5 213 0760 00 4 SCREW TPG TF 8 32 X 0 875 SPCL TAPTITE FILH 93907 ORDER BY DESC STLT20TORX 6 426 2204 00 1 FRAME SECT CAB BOTTOM LEFTVM700T 0J7N4 426 2204 00 7 211 0507 00 1 SCREWMACHINE 6 32X 0 312 PNH STLPOZ TK0435 ORDER BY DESC 8 426 2203 00 1 FRAME 9ECTCAB BOTTOM RIGHTVM700T 0 7N4 426 2203 00 9 211 0507 00 3 SCREW MACHINE 6 32 X 0 312 PNH STLPOZ TK0435 ORDER BY DESC 10 426 2202 00 2 FRAME SECT CAB TOP RIGHT LEFT VM700T 0 7N4 426 2202 00 11 211 0507 00 7 SCREW MACHINE 6 32 X 0 312 PNH STL POZ TK0435 ORDER BY DESC 12 124 0430 00 4 STRIP TRIM CORNER W STEP 20 0 61153 124 0430 00 13 348 0632 00 4 SHLD GSKT ELEK FINGER TYPE 19 0 LLCNR LEFT 80009 348 0632 00 14 348 0633 00 4 SHLD GSKT ELEK FINGER TYPE 19 0L CNR RIGHT 80009 348 0633 00 15 343 1070 00 8 RTNRELEKSHLD STAINLESS STEEL 0J7N4 343 1070 00 16 386 6950 00 1 PANELREAR REAR PANEL 0 100 700 TK1943 386695000 17 211 0507 00 SCREW MACHINE 6 32 X 0 312 PNH STLPOZ TK0435 ORDER BY DESC 17a 211 0504 00 2 SCREW MACHINE 6 32 X 0 250 PNH STL POZ TK0435 ORDER BY DESC 18 213 0808 00 4 SCREW TPG TR 8 32 X 0 625 L TAPTITE FILH 93907 ORDER BY DESC STL POZ 19 200 2222 00 B010100 B029999 1 GUARD FAN 7912AD 81041 6 182 033 20 119 2616 02 1 FAN 24VDC 28A 6 7W W LEADS 17 0L VM700T 0 2
147. FO as well as latching whether a line or frame pulse or an over flow or under flow has occurred Reading the Min Max results resets the circuit to begin a new accumulation VM700T Video Measurement Set Service Manual Theory of Operation VIDEOINPUT 16 VIDEOCLOCK DATA BUS INTERFACE ACQUISITION CPU 22 lt gt CPU DATA DATA CONTROL IN MIN MAX CLOCK IN ACQUISITION CONTROL CPU CONTROL DATA CLOCK FIFO OCCUPANCY FIFO CONTROL CPU DSACKS f DSACKI CONTROL CPU CPU INTERFACE HANDSHAKE CPU RAM ADDRESS ADDRESS CONTROL RAM ADDRESS 16 MHZ XTAL CLOCK OUT CLOCK IN Figure 3 7 Acquisition circuitry block diagram VM700T Video Measurement Set Service Manual CONTROLIN FIFO DEMULTIPLEXOR ACQUISITION DATA IN ACQUISITION CLOCK 4 ACQUISITION DATA OUT d gt CLOCK IN OCCUPANCY OUT gt CONTROL IN STATIC RAM RAM DATA BUS CONTROL IN E gt ADDRESS 5 SIGNALS TO CONTROL SECTION 3 21 Theory of Operation 3 22 Controller Section Bus Buffers Controller ASIC Address Decoding Output Latches and Analog Input Board Interface Clamp Counters The controller portion of the board performs the following functions m controls the VM700T analog front end receives and processes digitized data from the ADC board and passes it to
148. Hz Tektronix TSG 170A or equivalent Coaxial cable 75 Q high quality noise free 1 meter length Tektronix 012 0074 00 m Termination 75 Q precision BNC Tektronix 011 0102 01 or equivalent Specification Checked Burst frequency accurate to 10 Hz using the internal frequency reference NOTE The frequency of the signal generator used must be accurate to 1 Hz to ensure a valid limit check reference on the burst frequency measurement Procedure Measuring the Burst Frequency 1 Disconnect all signal inputs from the measurement set 2 Press the Measure hardkey and touch the Video soft key if necessary to recall the Video measurement menu 3 Touch the Burst Frequency soft key With no signal applied the measure ment set displays a warning message that tells you to check the signal source because a signal cannot be found The burst frequency measurement starts automatically after 3 seconds the Loss of Sync indicator blinks VM700T Video Measurement Set Service Manual Performance Verification 4 Press the Menu hardkey and touch the Reference soft key in the menu display 5 Touch the Zero Set soft key to set the measurement reference for the internal oscillator 6 Connect the signal generator full field and burst to the channel A input terminate the loop through with a 75 Q BNC termination 7 Check that the burst frequency measurement is 0 10 Hz using the internal frequency reference NOTE
149. If the measurement result obtained is outside of the specification limits go to Adjusting the Genlock Voltage Controlled Oscillator on page 5 3 in the Adjustment Procedure section VM700T Video Measurement Set Service Manual 4 11 Performance Verification 4 12 VM700T Video Measurement Set Service Manual Audio Option Verification Procedure The procedures in this section are designed to verify the operation of the VM700T Video Measurement Set Audio Option 40 and Audio Option 41 Before performing these procedures we recommend that you run the audio option diagnostics to ensure that the Audio Processor and Audio Analog boards are working properly Refer to the VM700T Option 01 NTSC amp Option 11 PAL User Manual or the VM700T Video Measurement Set Service Manual for information on how to select and run the Audio Option diagnostics NOTE Performing the following procedures requires the fabrication of non standard adapters and cables These are used to connect a sine wave generator to the VM 700T audio option The following list of test equipment describes the cable ends needed except for the provided female XLR to male mini XLR adapter cable locating the components and fabricating the cables is the responsibility of the user Test Equipment Required The test equipment needed to perform the verification procedures is listed in Table 4 2 Test equipment suggestions for use in doing the verification
150. L DEVICES 28520 HEYCO MOLDED PRODUCTS 81041 HOWARD INDUSTRIES INC 7X318 KASO PLASTICS INC TK2647 INSTRUMENT SPECIALTIES CO INC TK0435 LEWIS SCREW CO 75915 LITTELFUSE INC 05791 LYN TRON INC 0 7N9 MCX INC 2X013 MCGUIRE BEARING COMPANY 13893 MICRODOT INC TK1547 MOORE ELECTRONICS INC Address P D S DIVISION 50 W ARLINGTON ST UNIT H 2682 W COYLE AVE CUSTOMER SERVICE DEPT PO BOX 3608 12700 SW HALL ZA 6136 NE 87TH AVENUE 2200 US HWY 27 SOUTH PO BOX 1980 NAMEPLATE DIVISION 571 346 ELIZABETH BRADY RD 4 THOMAS ST DIVISION COOPER INDUSTRIES INC PO BOX 14460 ATTN ALICIA SANFORD 516 18TH AVE P 0 BOX 40000 P BOX 4200 M S 16 207 475 NAUTILUS COURT S 312 EAST MAIN STREET 14701 DETROIT AVE PO BOX 376 111 INDUSTRIAL RD PO BOX 76500 PO BOX 39100 750 BOULEVARD PO BOX 160 DIVISION OF MSL INDUSTRIED INC P 0 DRAWER 287 11013 A NE 39TH C O TEMCO NW 1336 SE 51ST STREET 4300 SOUTH RACINE AVENUE 800 E NORTHWEST HWY SOUTH 6001 THOMAS MALLEN RD 2977 CENTURY COURT 947SE MARKET ST 50631 E RUSSELL SCHMIDT BLVD 19500 SW 90TH CT PO BOX 1030 VM700T Video Measurement Set Service Manual City state zip code YAKIMA WA 98902 ELK GROVE VILLAGE IL 60007 HARRISBURG PA 17105 3608 TIGARD OR 97223 PORTLAND OR 97220 RICHMOND IN 47374 HILLSBOROUGH NC 27278 IRVINE CA 92718 ST LOUIS MO 63178 ROCKFORD IL 611045181 HARTFORD CT 06151 BEAVERTON OR 9
151. L POZ CABINET ASSY BOTTOM PORTABLE E 5 CABINET ASSY BOTTOM PORTABLE SCR ASSEM WSHR 6 32 X 0 312 PNH STL POZ CABINET ASSY BOTTOM PORTABLE FOOT CABINET BOTTOM BLACK POLY CARBONATE SCREW MACHINE 6 32 X 0 312 FLH 100 DEG STLPOZ PAD CAB FOOT 0 69 X 0 255 X 0 06 PU COVER PROT 17 164 X 9 0 P LASTIC CA ASSY PWR 3 18 AWG 250V 10A 98 INCH STR IEC320 RCPT X NEMA 5 15P US SAFETY CONTROLLED TERMN COAXIAL 75 OHM BNC FOOT CABINET CHARCOAL GRAY POLYURETHANE CABLE ASSY ADAPTER RS 232 9 PIN FEMALE TO 25 PIN MALE MANUAL TECH USER OP 01 11 NTSC AND PAL MANUAL TECH PROGRAMMER RS232 FUSE CARTRIDGE 3AG 3A 250V 30SEC UL LISTED CSA CERT Mfr code 5Y400 5Y400 93907 80009 80009 93907 80009 80009 93907 80009 0 01 0588 2 013 86928 06666 13893 06666 5 400 93907 5 400 5 400 93907 5 400 5 400 93907 5 400 5 400 93907 5 400 TK1161 93907 85471 80009 0B445 80009 0 R05 80009 TK2548 TK2548 71400 Mfr part number 390 1021 03 390 1021 03 821 12790 024 390 1023 00 390 1023 00 821 12790 024 390 1022 00 390 1022 00 821 12790 024 367 0366 00 211 0755 00 213 0940 00 IRR 7100 18 2B ORDER BY DESC C 720 3 ORDER BY DESC C 1252 390 1020 04 821 12790 024 390 1025 01 390 1025 01 821 12790 024 390 1028 01 390 1028 01 821 12790 024 390 1021 03 390 1021 03 821 12790 024 ORDER BY DESC ORDER BY DESC ORDER BY DESC 348
152. Line button to enter the menu The recommended baud rate setting for most applications is 9600 baud If the display is not working this is the baud rate to try first for viewing the diagnostics information The VM700T is capable of 38800 baud If the display is working you can set the baud rate as high as your terminal or terminal emulation program will handle Be sure to set the baud rate of the terminal to match Low Level Diagnostic Interface knob moves cursor Select Line inputs selection DIAGNOSTICS CONFIGURATION MENU Key Selection P Set Diagnostics POWERUP MODE I Set Diagnostics INTENSITIES B Set Low Level Diagnostics BAUD RATE Reprint 8 Abort Menu Input your selection Figure 6 58 Diagnostics Configuration menu VM700T Video Measurement Set Service Manual Troubleshooting Procedures Connecting a Terminal or PC The VM 700T has two DB9 RS 232C DTE serial ports on its rear panel see Figure 6 59 These serial ports can be used to send graphics and reports to a printer for remote operation via a modem or for viewing diagnostics by direct serial connection to an RS 232C device such as a terminal Both serial port 9 pin male D connectors are located on the A20 CPU I O board and are accessible from the rear panel of the instrument as shown in Figure 6 59 Fan exhaust 5050906010 Para
153. Lines VM700T Video Measurement Set Service Manual uuu Service Safety Summary Only qualified personnel should perform service procedures Read this Service Safety Summary and the General Safety Summary before performing any service procedures Do Not Service Alone Do not perform internal service or adjustments of this product unless another person capable of rendering first aid and resuscitation is present Disconnect Power To avoid electric shock disconnect the main power by means of the power cord or if provided the power switch Use Caution When Servicing the CRT To avoid electric shock or injury use extreme caution when handling the CRT Only qualified personnel familiar with CRT servicing procedures and precautions should remove or install the CRT CRTs retain hazardous voltages for long periods of time after power is turned off Before attempting any servicing discharge the CRT by shorting the anode to chassis ground When discharging the CRT connect the discharge path to ground and then the anode Rough handling may cause the CRT to implode Do not nick or scratch the glass or subject it to undue pressure when removing or installing it When handling the CRT wear safety goggles and heavy gloves for protection Use Care When Servicing With Power On Dangerous voltages or currents may exist in this product Disconnect power remove battery if applicable and disconnect test leads before removing protective panels
154. Low Level Diagnostic Interface CPU Diagnostic Configure CUSTOM RUN MODE parameters as desired build edit sequence then select RUN to begin execution Key Selection S SEQUENCE Type CUSTOM 1 Advance Mode MANUAL 2 Result Display Mode SHOW ALL 3 Result Logging Mode B BUILD New Test Sequence Reprint Q Abort Menu Input your selection Figure 6 36 Custom run mode menu From this menu you can select how the diagnostic advances to the next test as Automatically Advance on Pass Advance on Fail or Manually You can select how the results are displayed from the choices of Show Show Main Results or Show Minimum Required Results How the results are logged is also selectable from a choice of Log the Main Results Log all the Test Results Log the Minimum Required Results and Disable Results Logging After you have built a custom test sequence the added choices of running the test sequence and editing the test sequence are added to the list of menu choices To build a custom testing sequence select B Build to display the entire list of diagnostics for the selected board In Figure 6 37 Display Diagnostics was the selected set of tests The other low level diagnostics have a different list of test choices as appropriate for the board being tested 6 62 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Low Level Diagnostic Interface Display
155. MA9 12 DATA 0 3 BUFFER SMA0 8 500 8 5 1128 2 16 sp1227 3 SD29 31 500 10 CONTROL DATA T DYNAMIC OE 16 BIT COUNTER ADDRESS LATCH RCO SMA13 fsck CONTROL DYNAMIC ADDRESS gt SETTINGS BUFFER 5 STATIC RAM OUTEUT LATCHES 11 2 32 AND ANALOG CONTROL Figure 3 8 Controller section block diagram VM700T Video Measurement Set Service Manual BOARD INTERFACE DATA BUFFER 3 23 Theory of Operation Status Counter ECL To TTL Conversion Data and Address Latches 3 24 onto the BCDp 2 Bus Trigger RAM Sequencer State Machine A triple timer counter counts status pulses from the acquisition section of the board The status pulses may be used by applications to indicate events occurring in an acquisition pattern The differential ECL signals from the ADC board D0 D9 FRAME OUT LINE OUT CKD and OVERRANGE are converted to single ended TTL outputs before being used by the Acquisition Controller board A TTL to ECL conversion of OLS and PSR to ECL levels is also done These signals Sync Reset and Async Set control the modes of the ADC board so that it either outputs all ones or zeros or does conversion operations The data from the ADC board are latched into data latches and clocked out by SCLK to resynchronize the data to the clock signal Controller ASIC loads an address latch with 10 bits of address Three additional bits BCD13 15 are added from to complete the
156. MPLIFIER IDC 10 28AW 06009 174 3850 00 G 050 RND L 17 50 2 X 5 FEMALE RCPT 0 10 X 0 1 4 174 3848 00 030100 1 CA ASSY RF RFD CRIMP 1 75 OHM L 7 50 5 060D9 174 3848 00 BOTH ENDS 414002 1 VM700T 15 5 174 3891 00 8030100 1 CA ASSY RF COAXIAL RFD 1 750HM RG179 7 25 060D9 174 3891 00 L BNC ACK PANEL MOUNT FRONT MOUNT STR KINGS 20 6 174 3849 00 B030100 1 CA ASSY RF DISCRETE SER VID 060D9 174 3849 00 OUT RFD CRIMP 1 75 OHM L 9 50 SMB AMP 414002 1 X BNC BULK 7 343 0549 00 8 030100 1 STRAP TIEDOWN E 0 098 W X 4 0 L ZYTEL 06383 8 672 1504 00 8 030100 1 CIRCUIT BD ASSY INPUT amp BNC 671 4237 00 80009 672 1504 00 WIRED VMUPG 15 9 386 4247 00 8 030100 1 PLATE ADAPTER ALUMINUM TV GRAY 80009 386 4247 00 10 211 0409 00 B030100 4 SCR ASSEM WSHR 4 40 X 0 01 211 0409 00 0 312 PNH STL CDPL T 10 TORX DR 11 333 4247 00 B030100 1 PANEL REAR ALVM700T 19 9AFETY CONTROLLED 1943 333 4247 00 12 159 5010 00 8 030100 1 FUSE SMD 7A 125V FAST BLOW 0 1 X 0 1X 0 24UL 75915 451007 REG C9ACERT 13 159 5011 00 B030100 1 FUSE THRM CHIP SELF RESETTING FUSE 1 25A 06090 5 0125 2 HOLD 2 5ATRIP AT 20 DWG C 15V MAX T amp R 10 14 VM700T Video Measurement Set Service Manual Replaceable Mechanical Parts Replaceable electrical parts list Component number 10 6 1 2 20 Tektronix part number 159 5014 00 159 5014 00 159 5014 00 159 5014 00 159 5011 00 159 0193
157. Manual Specification Table 1 65 Luminance Non Linearity Measurement Absolute mode accuracy Relative mode accuracy Luminance Non Linearity 0 to 100 0 2 Table 1 66 Multiburst Measurement Range Absolute mode accuracy Relative mode accuracy Reference Flag or Packet Amplitude 30 IRE to 130 IRE 1 NA Other Packets 0 5 1 25 2 0 3 0 3 58 40 dB to 6 dB 0 1 dB 0 03 dB 4 1 MHz Table 1 67 Noise Spectrum Measurement Absolute mode accuracy 50 4 dB 20 dB to 60 dB 1 0 dB 60 dB to 70 dB 20 dB to 80 dB 1 0 dB 20 dB to 60 dB 22 0 dB 60 dB to 70 dB Unweighted Signal to Noise Ratio 20 dB to 80 dB 5 MHz Low Pass Weighted Signal to Noise Ratio 5 MHz Low Pass and Unified Weighting Table 1 68 SCH Phase Measurement SCH Phase Sync Relative Timing Absolute mode accuracy 5 10 ns Burst Relative Phase 5 Table 1 69 Short Time Distortion Measurement Range Absolute mode accuracy Short Time Distortion 0 to 25 SD 5 SD Table 1 70 TwoField Measurement Range Absolute mode accuracy Field Time Distortion 0 to 40 0 5 VM700T Video Measurement Set Service Manual 1 23 Specification Table 1 71 VITS ID Measurement VITS Recognition Performance requirement Supplemental information Recognizes and displays the name of recognized signals in the vertical interval of both Field 1 and Field 2
158. O 11751 6520 N BASIN AVE 1812 16TH AVENUE PO BOX 487 300 CONSTITUTION DR 7441 LINCOLN WAY DIVISION OF ILLINOIS TOOL WORK ST CHARLES ROAD 456 SEASTROM STREET 810 SE SHERMAN 3000 COLUMBIA HOUSE BLVD SUITE 1 1775 NW CORNELIUS PASS RD 3000 LEWIS amp CLARK HWY SUITE 2 14150 SW KARL BRAUN DR PO BOX 500 3000 LEWIS amp CLARK HWY PO BOX 66008 1880 SW MERLO DRIVE 29 01 BORDEN AVE P BOX 1030 DIV OF XEROX CORPORATION 14181 SW MILLIKAN WAY 91 3 COLIN DRIVE City state zip code HILLSBORO OR 97124 6474 DELAWARE WATER GAP PA 18327 EULESS TX 76039 SALEM OR 97303 TINLEY PARK IL 60477 3048 GARDENA CA 90247 4203 TIGARD OR 97223 TACOMA WA 98409 LEXINGTON KY 40509 PORTLAND OR 97217 FOREST GROVE OR 97116 0487 MENLO PARK CA 94025 1111 GARDEN GROVE CA 92641 ELGIN IL 60120 TWIN FALLS ID 83301 PORTLAND OR 97214 4657 VANCOUVER WA 98661 HILLSBORO OR 97124 VANCOUVER WA 98661 BEAVERTON OR 97077 0001 VANCOUVER WA 98666 6008 BEAVERTON OR 97006 LONG ISLAND CITY NY 111014478 BEAVERTON OR 97005 HOLBROOK NY 11741 VM700T Video Measurement Set Service Manual Replaceable Mechanical Parts Replaceable parts list Fig amp index Tektronix number part number 10 1 1 331 0508 06 2 211 0517 00 3 210 0055 00 4 210 0802 00 5 Notused 6 378 0322 00 7 354 0691 01 8 378 0323 00 9 354 0691 01 10 378 0325 00 11 354 0691 01 12 378 032
159. PECIAL INCIDEN TAL OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VEN DOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES Contacting Tektronix Phone Address Web site Sales support Service support Technical support This phone number is toll free in North America After office hours please leave a 1 800 833 9200 Tektronix Inc Department or name if known 14200 SW Karl Braun Drive P O Box 500 Beaverton OR 97077 USA www tektronix com 1 800 833 9200 select option 1 1 800 833 9200 select option 2 Email techsupport tektronix com 1 800 833 9200 select option 3 1 503 627 2400 6 00 a m 5 00 p m Pacific time voice mail message Outside North America contact a Tektronix sales office or distributor see the Tektronix web site for a list of offices VM700T Video Measurement Set Service Manual Table of Contents Specification Operating Information General Safety Summary 2 Service Safety Summary Prelate PEPPER Electrical Characteristics 22552755545 a a Dn etr e PO SS Physical Characteristics Power Requirements ios sess rb ERE pda Environmental 222b hee Bare eee aes Power Line Conditioner for Option Al and A2 Power Cords PAL Measurement Specifications
160. S Select a diagnostic to execute from the list below Key Selection Main Bd CPU Diagnostics Main Bd Display Diagnostics Main Bd Fr Pnl Infc Diagnostics I 0 Board Diagnostics Optional GPIB Board Diagnostics Optional Audio Board Diagnostics WD YS Reprint 8 Abort Menu Input your selection Figure 6 34 Low level diagnostics menu The low level diagnostics consists of sets of tests that check the CPU central processing unit including the display system and the front panel interface and the I O board circuitry With the addition of the optional hardware for GPIB or Audio low level diagnostics are provided to test that hardware These tests are bypassed at normal power on unless they are configured to run by the user Usually this power up running of diagnostics will be the only use of diagnostics for the user A service person can use the diagnostics to assist in determining if a board or board set is faulty before doing a board swap to effect repairs to the VM700T The normal use of the diagnostic tests is for factory testing prior to shipment to the customer and repair testing of the boards returned in the board exchange program VM700T Video Measurement Set Service Manual Troubleshooting Procedures Selecting an Overall Run Mode After you select one of the diagnostics to execute you get a further choice of how you want to run it The choices are shown in the Main Bd
161. Service Manual Tektronix VM700T Video Measurement Set 070 9630 04 Warning The servicing instructions are for use by qualified personnel only To avoid personal injury do not perform any servicing unless you are qualified to do so Refer to all safety summaries prior to performing service www tektronix com Copyright Tektronix Inc rights reserved Tektronix products are covered by U S and foreign patents issued and pending Information in this publication supercedes that in all previously published material Specifications and price change privileges reserved Tektronix Inc P O Box 500 Beaverton OR 97077 TEKTRONIX and are registered trademarks of Tektronix Inc WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one 1 year from the date of shipment If any such product proves defective during this warranty period Tektronix at its op tion either will repair the defective product without charge for parts and labor or will provide a replacement in ex change for the defective product In order to obtain service under this warranty Customer must notify Tektronix of the defect before the expiration of the warranty period and make suitable arrangements for the performance of service Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix with shipping charges pre
162. Slide back the right side cover to access the CPU board dip switch Set switch 4 of the dip switch to closed and then slide the cover forward to enclose the circuitry See Figure 5 12 on page 5 27 Press the VM700T front panel Menu button Touch the Waveform soft key and then touch the Full Signal soft key Eye Diagram F2 L97 scanning 270Mb 525 line Auto detect X Adjust distances A and B to the same size X B 0 2 0 0 0 2 0 4 0 6 0 8 1 0 1 2 Unit Intervals Filter 1 Khz DC OffsetiO0 5 mv Rise Fall Adjusted on Cable Len Bel 8281 22 meters Mode Waveform Cursors Rescale Eye Units 2 Figure 5 14 Adjusting the rising edge of the SDI Eye Diagram application 5 30 VM700T Video Measurement Set Service Manual Adjustment Procedure NOTE The following step adjusts the 18 MHz reference oscillator by observing the slip rate between the oscillator and the 1 MHz WWV reference signal A slip rate of 10 ns per second results in a maximum error of 0 01 ppm 5 Perform the following step to adjust the 18 MHz reference oscillator a Slide back the right side cover to access the SDI board test point and adjustment resistor See Figure 5 12 on page 5 27 Connect the 1 MHz WWV reference signal to channel 1 of your oscilloscope Connect a probe from channel 2 of the oscilloscope to TP17 on the SDI board See Figure 5 12 on page 5 27 Set the oscillos
163. Std 488 1979 para 3 2 Connects to VM 700T inter Data Transfer Rate Greater than 1 kbyte per Second Connectors GPIB Standard GPIB parallel connector VM 700T 3 x 50 square pin connector VM700T Video Measurement Set Service Manual connection board 1 35 Specification 1 36 Table 1 96 GPIB Electrical characteristics cont Performance requirement Characteristic Comments Power Requirements 45V Power Consumption 35 W maximum 45 Vin 10 A fast blow Located on the GPIB module Table 1 97 Mechanical specifications Characteristic Description Construction Plug in circuit board Designed for installation in the VM 700T left side card cage Multilayer ECB material FR4 Dimensions Length 11 inches 279 4 mm includes board retainer Width 7 785 inches 200 mm includes VM 700T connector Height 1 plug in unit high 15 16 inch 23 8 mm Shipping Weight Approximately 4 Ib includes GPIB board manual and packing materials Table 1 98 Optional accessories Item GPIB Cable Description 1m double shielded Tektronix Part No 012 0991 01 2 m double shielded Tektronix P art No 012 0991 00 3 m double shielded Tektronix P art No 012 0991 02 Software and manual plus National PC2A GPIB controller board and GPIB cable Tektronix P roduct No S 3FG 100 GURU 11 GPIB User s Resource Utility for the IBM Personal Computer VM700T Video Measurement Set
164. T BD ASSY ACQUISITION MEMORY A18 80009 671 4108 01 671 4108 02 031022 1 CIRCUIT BD ASSY ACQUISITION MEMORY A18 80009 671 4108 02 671 4356 00 8 030100 8031018 1 BD ASSYACQUISITION MEMORY 18 80009 671 4356 00 1 671 4356 01 031019 1 CIRCUIT BD ASSY ACQUISITION MEMORY 18 80009 671 4356 01 15 34 Notused 35 671 2470 00 8010100 B010842 1 CIRCUIT BD ASSY CPU A5 80009 671 2470 00 671 2470 01 8 010943 B029999 1 CIRCUIT BD ASSY CPU A5 80009 671 2470 01 671 2470 02 8030100 B030566 1 CIRCUIT BD ASSY CPU A5 80009 671 2470 02 671 2470 03 8 030567 1 CIRCUIT BD ASSY CPU A5 80009 671 2470 03 36 343 1328 00 1 RTNR CKT BOARD LEFT VM700T 5Y400 ORDER BY DESC 37 213 0919 00 1 THUMBS CREW 6 32 0 312 X 0 25 OD SST 0 01 213 0919 00 38 354 0163 00 1 RING RETAINING TYPE E EXT U O 0 125 ID SFT 79136 5133 1270 39 348 0102 00 1 PAD CUSHIONING 13 76 X 0 67 X 0 188 RUBBER 2K262 ORDER BY DESC 40 386 6667 00 2 PANEL BLANK 80009 386 6667 00 41 211 0661 00 3 SCR ASSEM WSHR 4 40 X TK0435 ORDER BY DESC 0 25 PNH STL POZ MACHINE 42 671 2799 00 8010100 8029999 1 CIRCUIT BD ASSY 1 0 20 80009 671 2799 00 671 2799 01 030100 1 CIRCUIT BD ASSY 1 0 A20 80009 671 2799 01 43 211 0661 00 1 SCR ASSEM WSHR 4 40 X 0 25 PNH STL POZ TK0435 ORDER BY DESC 44 386 6662 00 1 PANEL CKT BD DOUBLE BLANK W OUT 40 OR 80009 386 6662 00 0 41 45 Notused 46 672 1298 00 05 07 2001 1 CIRCUIT BD ASSY MOTHER A11 80009 672 1298 00 672 129
165. T Video Measurement Set Service Manual Mfr code 15915 15915 15915 15915 06090 61857 61857 61857 06090 06090 15915 15915 1857 1857 1857 1857 o o 61857 61857 06090 06090 Mfr part number R451 002 R451 002 R451 002 R451 002 SMD125 2 SP5 10A SP7 15A SP7 15A SMD125 2 5 0125 2 R451 015 451007 5 7 15 SPI 5A SP5 10A SP5 5A LEAD TAPE REEL SP7 1A SP5 2A SMD125 2 5 0125 2 10 15 Replaceable Mechanical Parts 10 16 VM700T Video Measurement Set Service Manual VM700T Video Measurement Set Service Manual 2 77 7 Yi ei Figure 10 1 Front assemblies and power supply 10 17 10 18 VM700T Video Measurement Set Service Manual Figure 10 2 Circuit boards 10 19 VM700T Video Measurement Set Service Manual 10 20 VM700T Video Measurement Set Service Manual Figure 10 3 Chassis assembly 10 21 VM700T Video Measurement Set Service Manual 10 22 VM700T Video Measurement Set Service Manual Figure 10 4 Cabinet and accessories 10 23 VM700T Video Measurement Set Service Manual 10 24 VM700T Video Measurement Set Service Manual J f f Figure 10 5 Option 1S circuit boards 10 25 VM700T Video Measurement Set Service Manual 10 26 VM700T Vide
166. Timing application NOTE The measurement reading you make in step e of this procedure assumes you are using the Tektronix TG2000 Signal Generation Platform for this check For VM700T firmware version 980422 and below there is a built in timing offset of 224 4 usec For VM700T firmware version 990512 and above there is a built in timing offset of 2 0 usec a Connect an NTSC black burst signal to the Option 1S Analog Ref input Terminate the Analog Ref loopthrough using a 75 Q terminator b Replace the 360 Mb signal on the SDI Ch A input with a 270 Mb 525 line 100 color bars signal Leave the SDI Ch A input terminated with the high frequency terminator Press the VM700T front panel Measure button and then touch the SDI IC Timing soft key d Press the front panel Menu button and then touch the Relative Analog soft key e Check the interchannel timing measurement reading m VM700T firmware version 980422 and below 224 0 to 224 8 us m VM700T firmware version 990512 and above 41 6 to 42 4 us 2 Perform the following steps to check the digital to digital mode of the SDI Interchannel Timing application a Remove the signal cable and terminator from the Option 1S Analog Ref input and then remove the terminator from the SDI Ch A input loopthrough b Connect a one meter cable from the SDI Ch A input loopthrough to the SDI Ch B input Touch the Relative Digital soft key d Check for an interchann
167. ace supports 1 2 and 4 MB SIMM parts Flash EPROM program memory is stored in Flash EPROM Programming of the Flash EPROM is possible through the parallel printer port for system upgrades Byte word 3 bytes and long word access are allowed in read mode Writes are restricted to long word access during device programming The memory defaults to read only at power up or after a system reset DRAM This is the microprocessor s working memory space Memory sizes of 4 8 or 16 Megabytes in SIMM boards are supported A dynamic RAM controller provides the interface between the dynamic RAM and the CPU microprocessor Real Time Clock single time keeper device provides a real time clock alarm watchdog timer and interval timer Display ASIC and VRAM display ASIC application specific integrated circuit processes the display information and prepares it for display The video RAM is divided into eight bit planes display memory layers Data to be displayed is loaded in the video RAM Data is then read out of the VRAM as required for the display updates Refresh information is written into alternate bit planes as the display data is being read from the active bit plane A VGA output from the display system permits viewing the display on an external VGA monitor The VGA connector is located on the back panel of the VM 700T VM700T Video Measurement Set Service Manual 3 17 Theory of Operation Front Panel Processor CPU IO Board A
168. ach byte has separate write enables because the CPU accesses only a byte at a time The static RAM is connected to the DSP address and data buses VM700T Video Measurement Set Service Manual Theory of Operation P Memory X Data and Y Data Memory Program Loading Control Lines The program memory the instructions for the DSP may be held in either 16K X 4 or 64K X 4 memory parts Jumper connections on the board select the correct device memory size for the parts installed These memories are the X data memory for the DSP and the Y data memory The DSP also has some small internal P X and Y memory These three internal memories P X and Y can be accessed at the same time by the DSP Access to the external P X and Y memories is one at a time These memories are used mainly for storing look up tables and data and results for example fft and other intermediate results are stored here The program instructions are loaded into the P memory from the audio processor The usual action is for the audio processor to set the RESET bit to keep the DSP shut off and download the instructions into P memory Then the RESET is removed and the DSP executes the newly loaded code Each memory device has three memory control lines WE write enable CE chip enable and OE output enable All memory devices are output enabled at the same time the read enable signals determine which memory is actually accessed by the DSP Audio Analo
169. agnostic test results as they are performed Diagnostic tests that do not pass display a highlighted Fail message 7 The Rerun Test soft key lets you rerun diagnostic tests 6 106 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Option 1S Diagnostics Table 6 13 describes each the SDI diagnostic tests Table 6 13 SDI Option 1S diagnostic test descriptions Test name SDI board version SDI board ID bits Acquisition memory size System size Xcheck Description This is a miscellaneous group of tests which verify and or display the particulars of the SDI board and the environment it needs to work properly These tests are as follows There is an 8 bit board ID field encoded on the board The least significant 4 bits of this field are implemented by means of resistors R912 R913 R914 and R915 and can be influenced by installing or not installing these resistors The next 4 bits are encoded with the PAL U730 The first diagnostic in this group simply reads these 8 bits on the least significant 8 bits of the processor s data bus and displays the results Presently there is no formal method of rolling this ID field but installing and removing these resistors may provide a tool for manufacturing troubleshooting Hence the pass fail field will always show PASS The product configuration requires that any VM700T containing the S DI option also be equipped with a 1Mb acquisition memory on the Acquisiti
170. agnostics Selection file 1 Press the Configure button 2 Press the Configure Files soft key 3 Select the Diagnostics Selection file 4 Turn the control knob until the name of the diagnostic is highlighted Touching the vertical center of the left half of the screen selects the highlighted diagnostic touching the vertical center of the right half unselects it VM700T Video Measurement Set Service Manual 4 3 Performance Verification 5 Press the Update amp Exit soft key to write out save any changes to the file press the No change amp Exit soft key to leave the file as it was when it was last saved Power Up Diagnostics Selection Genlock Diagnostic Controller Diagnostic Acquisition Diagnostic ADC Diagnostic Rotate control knob AnalogInput Diagnostic to highlight the FilterBoard Diagnostic selection to be made GPIB Diagnostic AudioProcessor Diagnostic AudioAnalog Diagnostic Selected Line 8 Not Selected Figure 4 4 Power up diagnostics selection display As shown in Figure 4 5 the FilterBoard Diagnostic routine is in the Not Selected column and will not be performed Power Up Diagnostics Selection Genlock Diagnostic CO Touch this side of Controller Diagnostic the screen to deselect Acquisition Diagnostic the highlighted choice ADC Diagnostic AnalogInput Diagnostic FilterBoard Diagnostic GPIB Diagnostic AudioProcessor Diagnostic AudioAnalog Diagnostic Selected Line 8 N
171. alog circuitry plus a Memory Board series of MUX s to select between the analog and digital data streams and to change the handling of the flags portion of the data stream The Acquisition Memory board also adds a FIFO that allows the controller state machine to communicate information to the CPU without having to place the information in acquisition memory This is the FIFO that the SDI Format application s FIFO Overflow error refers to VM700T Video Measurement Set Service Manual 3 51 Theory of Operation 3 52 VM700T Video Measurement Set Service Manual OO A O Performance Verification Self Diagnostics The Verification procedures in the this section are done with the covers on the measurement set to verify its operation and may be used to determine the need for readjustment After a board exchange certain adjustments may be needed to compensate the overall system performance Follow the directions found in the adjustment section of this manual when readjustment is needed Performance to published specifications is verified by other methods during a factory calibration of the measurement set You can configure the measurement set to run the diagnostics at power up or to bypass all diagnostics at power up Refer to Setting the Power Up Mode on page 6 70 As received from the factory the diagnostics are configured to be bypassed for a quicker startup The diagnostic routines of the VM700T Video Measurement Set check the operation o
172. als to the option circuitry The GPIB Interface Option 48 add a standard GPIB connector for remote control and GPIB hardcopy output You can connect any video signal of the appropriate format to any of the three video inputs for normal operation The serial ports Port 0 and Port 1 can be used for output to serial printers or for remote control of the measurement set The printer output port supports Centronics compatible parallel printers The output provides support for viewing the measurement set display on a remote monitor Certain options such as Camera and Component require connections to specific inputs for correct operation Refer to the appropriate option user manual when connecting signals to make those option measure ments VM700T Video Measurement Set Service Manual 2 15 Operating Information Rear Panel and Connections The rear panel shown in Figure 2 10 includes the line voltage and switching module line voltage selector fuse holder a cooling fan the signal input connectors the VGA connector the parallel printer port and the RS 232 serial ports Fan exhaust 00 oOo Jee Jo Power Fuse ON OFF Line voltage VGA Parallel Alarm Portl Port0 connector Switch selector output printer port connector RS 232 ports Figure 2 10 VM700T Video Measurement Set rear panel The following paragraphs briefly describe
173. amplitude differences Channel Delay measures timing and amplitude differences as does Bowtie but it works with signals containing jitter m ColorBar measures the Y Pb and Pr amplitudes of each chroma packet W Factor measures K 2T K 5T and Pulse to Bar ratio on component input signals m Level Meter monitors peak to peak amplitude of a component signal m Lightning displays two XY graphs on the screen m Luminance NonLinearity measures luminance nonlinear distortion m Component Multiburst measures frequency response W Noise Spectrum measures noise level and performs spectrum analysis m Overlay displays stacked or superimposed Y Pb and Pr component inputs Parade displays side by side Y Pb and Pr component inputs B Vector provides an XY display of the Pb and Pr components VM700T Video Measurement Set Service Manual Options Audio Video Timing Measurement Option 42 The Audio Video Timing measurement option Option 42 of the VM 700T is part of a system that measures the timing difference between audio and video portions of a program that arrive from different transmission paths This feature is used in conjunction with the VITS200 NTSC or VITS201 PAL insertion generators and the ASG100 or ASG140 Audio Signal Generators that are also equipped with the Audio Video Timing measurement The VM 700T must have either Option 40 or Option 41 installed to operate with the Option 42 firmware Audio Options Opt
174. anels removing the ADC board disconnecting a flat cable and wire and removing seven screws With the screws removed the board may be lifted from the VM 700T chassis and set aside See Figure 6 16 for the location of the genlock board Use the following procedures to remove and replace the Genlock board Required Tools Use the following tools to remove the Genlock circuit board W Pozidriv screwdriver 2X Procedure Use the following procedure to remove and replace the Genlock board 1 Perform the following steps to remove the Genlock board a Remove the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 Remove the card cage retainer refer to step 1 on page 6 16 Disconnect the flat 10 conductor cable between J111 on the ADC board and J6 on the Genlock board see Figure 6 16 Disconnect the power bus cable at its five connectors and then remove the cable Disconnect the ribbon cable between the Genlock board and the Acquisition Memory board from the Genlock board at J8 Disconnect the wire at J10 Remove the seven board retaining screws and carefully lift the board from the VM 700T chassis 2 Perform the following steps to replace the Genlock board a Place the Genlock board carefully on its hardware standoffs ensuring that the ribbon cable is positioned with its connector through the slot in the right side of the instrument chassis see Figure 6 16
175. arrier Phase Modulation Measurement ICPM requires zero Carrier Pulse and the quadrature output ofthe demodulator on Channel C Accuracy Table 1 27 Jitter Measurement Range Absolute mode accuracy J itter 2 Field 20 us 10 ns J itter Long Time 20 us 10 ns Table 1 28 K Factor Measurement Range Absolute mode accuracy 2T Pulse K Factor 0 to 10 Kf 10 396 Kpg 10 to 5 Kpg 0 3 Pulse to Bar Ratio 10 to 125 0 7 Pulse Half Amplitude Duration HAD 100 ns to 500 ns 5 ns Table 1 29 Level Meter Level Meter 0to 14V 3 5 Table 1 30 Line Frequency Measurement Line Frequency Accuracy 0 1 Field Frequency 3 0 1 Table 1 31 Luminance Nonlinearity Measurement Range Absolute mode accuracy Relative mode accuracy Luminance NonLinearity 0 to 100 0 4 0 2 VM700T Video Measurement Set Service Manual 1 13 Specification Table 1 32 MultiBurst Measurement Relative mode accuracy MultiBurst Flag Amplitude NA Packets 1 5 0 5 1 0 2 0 4 0 4 8 MHz 0 03 dB Packet 6 5 8 MHz 0 06 dB Table 1 33 Noise Spectrum Measurement Range Absolute mode accuracy Unweighted Signal to Noise 20 dB to 80 dB 0 4 dB 20 dB to 60 dB 5 MHz Low Pass 1 0 dB 60 dB to 70 dB Luminance Weighted 20 dB to 80 dB 1 0 dB 20 dB to 60 dB Signal to Noise 2 0 dB 60 dB to 70 dB 5 MHz Low Pass and Unified Weighting Chrominance Weighted
176. ation 32 Bit Counter clock frequency of this counter defaults to 1 8432 MHz The clock frequency is controlled by bits from a status register It may be disabled set to the default frequency or set to either 921 kHz or 460 8 kHz Connector The connector circuitry provides a 32 bit address bus buffer and a 32 bit data bus buffer Addresses are unidirectional The data buffer 1s bidirectional to handle data both to and from the CPU I O board These busses are connected to the system bus for interconnection to the CPU VM700T Video Measurement Set Service Manual 3 19 Theory of Operation Data Acquisition Controller Board A18 3 20 Video Data and Clock Inputs FIFO Demultiplexor Acquisition Control Acquisition Clock Data Bus Interface Data Acquisition Memory Static RAM Min Max ASIC The combined Data Acquisition Controller board A18 does both data acquisi tions and controlling of the acquisition process The acquisition portion of the board is a programmable data interface between the ADC board and the CPU microprocessor The controller state machine can be programmed to recognize data sequences and generate signals to the data acquisition section telling it when to perform various tasks Figure 3 7 shows a block diagram of the data acquisition section of the Acquisition Controller board Data from the ADC board enters the Acquisition Controller board through a 34 pin connector The inputs are different
177. ave generator to the Option 41 audio input connector as in Figure 4 8 3 Press the Measure hard key select Audio and run the audio analyzer measurement VM700T Video Measurement Set Service Manual Audio Option 41 Triple Input Verification Procedure 4 Option 41 audio input connector Figure 4 8 Option 41 cable connections level accuracy and flatness check 4 Using a known accurate sine wave generator or one verified with an accurate AC voltmeter apply a 120 Hz input to the Audio option at amplitudes gt 20 dBu for example 18 8 2 and 12 dBu and verify that the level accuracy is 0 1 dB 5 Select at least 6 frequencies and 10 amplitudes to test The frequencies and amplitudes you select must be in the ranges listed in Table 4 5 use a signal amplitude level of 70 dBu to test for worst case Table 4 6 shows an example selection of test frequencies and amplitudes 6 Setthe sine wave generator for each of the selected frequencies and amplitudes a Record the level of each frequency b Verify that the measured levels recorded for each frequency are within the flatness specification given in Table 4 3 on page 4 15 Table 4 6 Example test signals for level and flatness test Frequency 30 Hz 100 Hz 1 kHz 5 kHz 12 kHz 20 kHz 7 Repeat step 5 for channels B and VM700T Video Measurement Set Service Manual Amplit
178. bezel if the screws are over tightened 6 32 VM700T Video Measurement Set Service Manual Maintenance Figure 6 19 Locating the bezel retaining screws STBY ON Switch Use the following procedure to remove and replace the STBY ON switch 1 Perform the following steps to remove the STBY ON switch a Remove the CRT bezel refer to CRT Bezel on page 6 32 b From the circuit side of the STBY ON switch remove the two nuts holding the switch assembly to the bezel See Figure 6 20 Separate the switch and its front plate from the bezel 2 Replace the STBY ON switch by performing step 1 in reverse order VM700T Video Measurement Set Service Manual 6 33 Maintenance 6 34 Key board bracket Figure 6 20 Disconnecting the STBY ON circuit board Keypad Board Assembly Use the following procedure to remove and replace the Keypad board assembly 1 Perform the following steps to remove the Keypad board assembly a b Remove the CRT bezel refer to CRT Bezel on page 6 32 Remove the right side card cage retainer refer to step 1 on page 6 16 Disconnect the interconnection cable at J9 on the CPU board Remove the flat head screws holding the Keypad board assembly bracket to the VM 700T front frame see Figure 6 21 Carefully separate the Keypad board assembly from the instrument On the back of the Keypad board assembly remove the touch
179. board connector and press firmly to seat the connector Reinstall each of the five cables to the SDI board ensuring that they are firmly seated in the board connectors see Figure 6 12 Install the card cage retainer refer to step 4 on page 6 17 Install the cover panel refer to Cover Panel Removal and Replacement on page 6 8 SDI Rear Panel Interface Assembly As you face the front of the VM 700T in the operating position the SDI Rear Panel Interface assembly A23 is located on the right side of the rear panel To remove this assembly you must first remove the right side cover and the card cage retainer so that you can disconnect four cables from the SDI board 6 20 VM700T Video Measurement Set Service Manual Maintenance VM700T right side Figure 6 12 SDI board A22 cable connections m Perform the following steps to remove the SDI Rear Panel Interface assembly a Remove the right side cover panel refer to Cover Panel Removal and Replacement on page 6 8 Remove the card cage retainer refer to step 1 on page 6 16 The SDI board occupies the second from the top slot in the right side card cage see Figure 6 10 on page 6 17 Disconnect the cables from the SDI board at J8 J7 J10 and J5 see Figure 6 12 Remove the four retaining screws from the SDI Rear Panel Interface assembly see Figure 6 13 Remove the SDI Rear Panel Interface assembly by carefully pulling t
180. brator such as a Fluke 5700A for this measurement Verify that the sine wave generator can meet the amplitude accuracy specifications listed in Table 4 2 Nov 1994 VM700T Video Measurement Set Service Manual EEE Audio Option 40 Verification Procedure Use the following procedures to check the Option 40 Audio Option Check Level Measurement Accuracy and Flatness Specifications Checked Option 40 Level Accuracy and Flatness November 1994 VM700T Video Measurement Set Service Manual This procedure verifies flatness and measurement accuracy by checking signal levels at specified frequencies NOTE The actual frequencies and levels checked are not specified in this procedure If the measurement accuracy of certain frequencies and levels is important to your application we recommend that your test procedure include those frequencies and levels Table 4 3 lists audio option accuracy and flatness specifications Table 4 3 Accuracy and flatness specifications Accuracy Frequency range Level range includes flatness Flatness 20 40 Hz gt 20 dBu 0 3 0 2 dB 0 1 0 2 dB 20 dBu to 50 dBu 0 4 0 3 dB 0 1 0 2 dB 50 dBu to 60 dBu 0 6 0 5 dB 0 2 0 3 dB 60 dBu to 70 dBu 1 0 dB 0 4 0 5 dB 40 Hz 20 kHz gt 20 dBu 0 2 dB 0 1 dB 20 dBu to 50 dBu 0 3 dB 0 1 dB 50 dBu to 60 dBu 0 5 dB 0 2 dB 60dButo 70 dBu 1 00 0 4 dB 1 Lev
181. cable on its connector at J6 on the Acquisition Memory board Install the flat 10 conductor cable between J6 on the Genlock board and J111 Install the shielded cable at J765 on the ADC Filter board VM700T Video Measurement Set Service Manual Maintenance J6 AE b L Q LE i 5 bus cable A A3A5 VM700T top view 16 ik EE on the 18 board sl A2 16 Figure 6 17 Removing the ADC board f Install the power bus cable at its five connectors g Install the card cage retainer refer to step 4 on page 6 17 h Install the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 29 Maintenance 6 30 Filter Switch Board Removal and Replacement Removing an
182. cation approximately 0 02 or less difference when compared to the 50 kHz reference 8 Setthe leveled sine wave generator for 5 8 MHz but do not change the output level setting 9 If Averaging is on speed up the response to the frequency change by toggling the Average hard key off then back on again after the display has re stabilized 10 Check that the amplitude is within 0 55 of the reference level stored in step 4 If it is in tolerance skip to step 11 If the amplitude is out of tolerance you can try the adjustment of step 7 again to set the amount of change Delta Amp to the positive side of the tolerance that is nearer the 0 02 limit as a compromise You may also need to start the procedure all over again to re establish the reference level it may have drifted slightly from when you first acquired it You should next determine if the problem is only on one channel or on all channels If only one channel is involved the Analog Input board may need the flatness adjustments for the input channels done that procedure is described in the Extended Adjustment Procedure later in this section If all channels are involved the ADC board may need adjustment or repair part of the Analog Input board is also a single channel signal path but the ADC board is the most likely problem area when all channels are affected VM700T Video Measurement Set Service Manual 5 7 Adjustment Procedure 11 12 13 14
183. ce 9 1 Figure 6 25 Removing the Interconnect board assembly retaining screws Cooling Fan Removing and replacing the cooling fan requires removing the top and bottom cover panels removing the power supply and removing the harness retainers that attach the fan s wire harness to the bottom of the left card cage With these items removed the cooling fan and it s guard can be removed by removing the retaining screws and nuts The following steps describe removing and replacing the cooling fan VM700T Video Measurement Set Service Manual 6 41 Maintenance 1 Perform the following steps to remove and replace the cooling fan a Remove the power supply module refer to Power Supply Module on page 6 38 b With cutters remove the plastic retainers holding the fan wire harness to the bottom of the left card cage c Disconnect the circuit board connector and separate the intercon nection cable from the fan housing d Remove the screws and nuts holding the cooling fan and separate the fan and its finger guard SN B029999 and below only or its EMI filter SN B030100 and above only or if Option 15 installed from the back panel See Figure 6 26 NOTE Remove the two screws accessible from the bottom first Then turn the instrument right side up remove the remaining two screws and carefully lift the fan clear of the instrum
184. ch are provided as standard accessories to the VM700T Video Measurement Set You must use an appropriate test signal to test the measurements You can obtain the test signals needed from an appropriate test signal generator In most cases the measurement set needs a video signal in a specific format NTSC or PAL to make a meaningful measurement Waveform mode displays can be of any signal that can be phase locked to the external sync source CHAN CHAN CHAN 1 DST1 t1 OO OO OO Figure 2 11 Video signal input connectors VM700T Video Measurement Set Service Manual Operating Information Connecting Audio Option 40 to a Source The 700 Audio option comes with two male mini XLR to female XLR adapter cables wired as shown in Figure 2 12 The mini XLR ends of these cables connect the Audio option input to an appropriate audio signal source WY Ve 4 Female XLR to male mini XLR adapter cable Figure 2 12 Cables and connectors supplied with Audio Option 40 Input Connector Pin See Figure 2 13 for the pin assignments for the Option 40 mini XLR connectors Assignments You access these connectors at the measurement set rear panel LEFT RIGHT INPUT INPUT 1 CH 2 Figure 2 13 Option 40 connectors and pin assignments VM700T Video Measurement Set Service Manual 2 19 Operating Information C
185. ck FH Statu Sound in S ync E 20 25 MHz clock Clock ON OFE 2 Generator Async or Sync EU Phase ON OFF 20 25 MHz SP Mode Window comparator Bai ode Cti 05 Lo ot BENE 11821227 4FSC Tr mee Sync Mod Mode oge Loop L 1720750 07 721277552777 7 Video Std 00 High Lock Status Locke Coarse 00 Low Correction History Decoded Frame Pulse 4FSC Output Generator 1 4F9C Sync or Async Mode r Frame Rate Synthesizer 4 or Async Mode 20 25 MHz Mode Z Decoded Frame Pulse Deglitcher ae Cloc Out Frame Mode o Rising Edge Synthesized Frame Pulse D 9 Clock S ync window 9ynthesized Frame Mode 9ynthesized Composite 9ync Frame Mode Figure 3 2 Genlock board A2 block diagram 3 8 Rising Edge i Detect pe O ai Decoded MHz Mode Frame Mode VM700T Video Measurement Set Service Manual Theory of Operation FH Generator FH generator provides NTSC or PAL line rate frequency reference clock to the phase locked loop using either the horizontal sync output from the sync stripper or the line rate frequency derived from the 20 25 MHz crystal clock The FH generator also provides a timing reference to
186. cont Fig amp index number 39 40 41 42 43 Tektronix part number 174 3652 00 337 4154 00 407 4585 00 119 5870 00 212 0189 00 Serial no Serial no effective discont d B020100 B030100 B030100 Qty Name amp description CA ASSY SP RIBBON IDC 10 28 AWG 24 0 L 2X5 CTR PLZ BOTH ENDS VGA CABLE SHIELD ELEC SLOTTED SHIELD RIVET MOUNT 8 626LX0 76W CU BE BRACKET EMI 0 062 THK RIGHT SIDE FRONTAL 5052 H3X ETCH amp CLEAR CHROMATE VM700T FILTER EMI FAN 0 050 AL 5052 H3X 4 7 X 4 7VM700T SCR ASSEM WSHR 8 32 X 0 500 PNH STL CDPL T 20 TORX DR MACHINE VM700T Video Measurement Set Service Manual Mfr code TK1547 TK2647 TK1943 30817 0 01 Mfr part number 174 3652 00 0097 0952 02 407 4585 00 119 5870 00 ORDER BY DESC 10 11 Replaceable Mechanical Parts Replaceable parts list cont Fig amp index Tektronix number part number 10 4 1 390 1020 03 390 1020 05 2 211 0658 00 3 390 1023 01 390 1023 02 4 211 0658 00 5 390 1022 01 390 1022 02 6 211 0658 00 7 367 0366 00 8 211 0755 00 9 213 0940 00 10 354 0025 00 210 0894 00 12 351 0104 03 13 210 0458 00 14 351 0636 00 15 390 1020 04 16 211 0658 00 17 390 1025 01 390 1025 02 18 211 0658 00 19 390 1028 01 390 1028 02 20 211 0658 00 21 390 1021 03 390 1021 05 22 211 0658 00 23 390 1021 01 24 348 0879 01 25 211 0538 00 26 348 0596 0
187. cope as follows 10 ns div DC coupled channel 1 to 500 mV div and 1 MQ DC input channel 2 to 500 mV div and 50 9 DC input and triggered to channel 1 WWV Adjust R490 on the SDI board see Figure 5 12 on page 5 27 so that the channel 2 signal display on the oscilloscope is stationary maximum horizontal drift of less than 1 division per second Remove the probe from TP17 on the SDI board Slide the cover forward and install the side cover retaining screws See Figure 5 10 on page 5 22 Remove all cables and terminators from the VM700T VM700T Video Measurement Set Service Manual 5 31 Adjustment Procedure 5 32 VM700T Video Measurement Set Service Manual OO A O Maintenance Preventive maintenance consists of cleaning visual inspection performance verification and if needed readjustment The preventive maintenance schedule established for the instrument should be based on its environment and the amount of use Under average conditions preventive maintenance should be performed every 12 months of operation NOTE If the instrument does not function properly troubleshooting and corrective measures should be taken immediately to prevent additional problems If the instrument fails during the warranty period contact your local Tektronix representative No user repair should be attempted during the warranty period This section contains the following information W Servicing preparation page 6 1 Insp
188. cs This block also requests a six bit filter ID from the filter in each slot and transmits it to the acquisition controller board The filter select and control block provides three types of outputs m Filter selection m Filter poll a request for filter I D m Filter control used only by the low frequency noise filter Slot 0 is the straight through path of the filter switch board it has no connectors for mounting a filter In place of a filter a resistor network provides a small amount of signal attenuation The loss of each filter in slots 1 5 is adjusted to match the loss from the resistance in slot 0 Slots 1 5 accommodate the five plug in filters The only filter with controllable parameters is the low frequency noise filter The 3 dB point on this filter can be set to 1 kHz 7 5 kHz 10 kHz or 15 kHz The output amplifier provides the 75 drive needed for the input to the analog input board When the acquisition controller board asserts FIL3 the output amplifier switches from unity gain to a gain of eight VM700T Video Measurement Set Service Manual Theory of Operation 1 8 SELECT Feces eo ee ee 71 FILTER 51070 To From SELECT amp i Acquisition CONTROL gt Video to Controller Analog Input Board sy T 6 OUTPUTAMPL Board aa 4 7 F SS SSS SS SLOT 1 J ial
189. ctor switch you must also change the fuse to provide proper protection for the operating voltage in use The 3A slow blow fuse provides the proper protection in the 230 VAC range and the 6A slow blow fuse provides protection for operation in the 115 VAC range A detachable three wire power cord with a three contact plug is provided with each measurement set for connecting to both the power source and protective ground The protective ground connector in the plug connects through the protective ground conductor to the accessible metal parts of the measurement set For electrical shock protection insert this plug only into a power source outlet that has a properly grounded protective ground contact Measurement sets are shipped with the power cord required for the country of destination Refer to the Options section for information on the available power cord options Contact your Tektronix representative or local Tektronix field office for additional power cord information European power cord options 1 and A2 require an additional accessory for operation in the EU countries When the VM700T Video Measurement Set is ordered with either the A1 or the A2 power cord option the VM700T Power Line Conditioning accessory is also provided The Power Line Conditioner accessory to the VM700T assures that the VM700T meets the Line Harmonics requirements of the European Union when operated from a 230 Vac mains source The line conditioner is for use o
190. current boot switch settings Key Selection NORMAL Start Instrument in Powerup Mode Current Powerup Mode is QUICK START abort this menu and go to the DIAGNOSTICS CONFIGURATION MENU to change it sews POWERUP DIAGS 44554 rm mee Da Diagnastics start Instrument Q us QUICK START Ss e bu IRI ERES Skip Diagnostics start Instrument L LOW LEVEL DIAGS LOOP Loop on Low Level Diagnostics D HIGH LEVEL DEBUG Start Instrument in HL Debug Mode A 0 0 5 Do EXTRA Diagnostics start Instrument Reprint 8 Abort Menu Input your selection Figure 4 2 Instrument run modes menu To check for soft errors possible intermittent operation run DiagsLoop on all the high level diagnostics while you let the measurement set warm for 20 minutes before starting the verification checks To set up for running all the high level diagnostics in a DiagsLoop do the following tasks at the completion of system initialization m Enter the Configure Directory shown in Figure 4 3 by pressing the Configure button M If you see a Diagnostic Errors file in the Configuration files either use the Delete soft key to erase it if it is not needed or check it for the last error saved and note its time for reference m Touch the Diagnostic Selections soft key m Set the Diagnostic Selection file shown in Figure 4 4 to run all diag
191. d In Waveform and Vector modes an inverted source can be the sole input or it can be added to another input In Measure mode an inverted source can only be added to another source m Source Invert To invert a single source press and hold the source button until the measurement set beeps approximately one second When a source is inverted the LED on the source button flashes To invert a second source and add it to another press and hold the normal source and while holding it quickly press and release the inverted source The LED on the inverted source will flash M Average Button The Average button enables uncorrelated or random noise reduction on the signal in Waveform and Vector modes and averaging of the signal in Measure mode The amount of noise reduction up to 30 10 dB is set with the Noise soft keys The number of averages up to 256 is set with the Average Num soft keys Support Functions The third row down in the keypad contains support functions Menu Help Configure Function and Copy Turn any of these functions on by pressing the associated front panel button Of these Copy turns off either after the copy is sent or after pressing the Cancel soft key that appears in the Configure menu when a copy is pending Help is turned off by pressing the Help button a second time The remaining functions are turned off either by pressing the button a second time or by selecting a different operational mode in the top TOW m Me
192. d replacing the Filter Switch board A4 consists of removing the instrument top and right side covers removing a flat cable assembly discon necting two wires and a cable and removing the screws holding the board in position With the screws removed the board may be lifted from the VM 700T chassis and set aside Replacing this board is the reverse of the removal procedure You may use the following procedures to remove and replace the filter switch board Required Tools Use the following tools to remove the Filter Switch circuit board W Pozidriv screwdriver 1X 2X Procedure Use the following procedure to remove and replace the Filter Switch board 1 Perform the following steps to remove the Filter Switch board a Remove the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 b Remove the card cage retainer refer to step 1 on page 6 16 c Disconnect the power bus cable at its five connectors and then remove the cable see Figure 6 18 d Remove the wire connecting A4 J915 to Al J922 at the J922 end only e Remove the wire connecting A4 J418 to A1 J923 at the 1923 end only f Remove the cable from its connector at J2 on the Acquisition Memory board A18 g Remove the five board retaining screws h Carefully lift the board from the VM 700T chassis and set it aside 2 Perform the following steps to replace the Filter Switch board a Ifthe board has an insulator sheet ho
193. d with a cloth dampened in water that contains a mild detergent or non abrasive glass cleaner Abrasive cleaners should not be used Cleaning the CRT Touch Screen Clean the CRT touch screen by carefully applying a small quantity of glass cleaner and wiping the screen dry with a clean nonabrasive lint free cloth Cleaning the Front Bezel Air Filters At regular intervals inspect the air filters through the front bezel air intake slots for accumulated dust Carefully vacuum the front of the instrument to remove any accumulated dust Cleaning the Interior Use low pressure dry air to remove accumulated dust and dirt high velocity air can damage some parts Hardened dirt or grease may be removed with a cotton swab or pipe cleaner dampened with isopropyl alcohol Abrasive cleaners should not be used If the circuit board assemblies must be removed for cleaning follow the instructions in the removal and replacement procedures of this section VM700T Video Measurement Set Service Manual Maintenance Visual Inspection CAUTION Do not allow water to get inside any enclosed assembly or component Do not clean any plastic materials with organic cleaning solvents such as benzene toluene xylene acetone or similar compounds because they may damage the plastic After cleaning allow the interior to thoroughly dry before applying power to the instrument After cleaning carefully check the instrument for defective connecti
194. decoder and two bits of data from the control knob Figure 3 11 shows the block diagram of the keypad board The control knob is a mechanical switch with conductive plastic contacts One terminal of the switch is grounded and the other two lines are connected to circuitry on the front panel board that decodes the knob s output The front panel push buttons are momentary contact single pole single throw switches divided into two groups of eight and one group of four The push buttons drive three 8 bit buffers which are read by the front panel processor enabled by KEY 0 2 Firmware provides contact debouncing The front panel LEDs are driven by three 8 bit latches The front panel processor writes bit patterns into the latches turning on the appropriate LED KEY O KEY KEY 2 Push Buttons Push Buttons FPD 0 7 To F rom Front Panel Reset Figure 3 11 Keypad board 10 2 block diagram VM700T Video Measurement Set Service Manual Theory of Operation Main Interconnect Board Left and Right A11 The VM 700T has both attached assemblies and plug in modules The plug in modules are supplied with power data address and control signals through the interconnections to the Main Interconnect Board There is a Left and Right board for the plug in modules on the left and right sides of the VM 700T and an interconnect board that ties the two sides together Picture Monitor A14
195. differences between channels is 0 2 dB at levels of 50 dBu and greater Audio Spectrum Specifications Table 1 89 General Audio Spectrum specifications Specification Description Normal Res mode High Res mode Display bandwidth DC to 24 kHz Any 3 kHz within the display bandwidth Frequency resolution 41Hz 6 Hz Cursorreadout Frequency t24Hz t3Hz Amplitude 0 5 dB 1 0 dB 0 5 dB 1 0 dB Frequency range for noise level 188 Hz to 20 kHz Selected 3 kHz window within the range of measurement 24 Hz to 24 kHz Signal Noise ratio gt 85 dB at full scale gt 70 dB for inputs 20 dBu with appropriate range selection Table 1 90 Audio Spectrum Level measurement specifications Frequency range 188 Hz 20 kHz Level range 2 20dBu 20 dBu to 50 dBu 50 dBu to 60 dBu 60 dBu to 70 dBu 1 32 Accuracy Flatness 0 2 dB 0 1 dB 0 3 dB 0 1 dB 0 5 dB 0 1 dB t 1 0 dB t 0 1 dB VM700T Video Measurement Set Service Manual Specification Table 1 91 Harmonic Analyzer measurement specifications Description Specification Comments HighestFundamental Frequency 9999 Hz Harmonics up to the 20 kHz measurement bandwidth are displayed Measurement U pdate Rate 6 readings per second View Harmonic Measurement Window 24 Hz All signal energy within the view window is measured Table 1 92 Miscellaneous specifications Description Specification Channel
196. djustment procedure done by Tektronix Customer Service Contact your nearest Tektronix representative for information Test Equipment Required m Gain phase analyzer 75 Q output impedance Example Hewlett Packard 4194A Impedance Gain phase analyzer m Leveled sine wave generator 75 output impedance output flat within 0 025 dB 0 3 to 6 MHz Example Hewlett Packard 3336C Sine wave generator with option 005 Coaxial cable 75 Q high quality low noise BNC 1 meter length 2 each Tektronix part number 012 0074 00 m Termination 75 feed through BNC Tektronix part number 011 0055 01 m Termination 75 Q precision BNC Tektronix part number 011 0102 01 m Female to female adapter BNC Tektronix part number 103 0070 00 M Adapter snap on SMB male to BNC female 2 each Example Omni Spectra part number 3280 2224 00 m Non metallic flat blade adjustment tool Tektronix part number 003 1364 00 Specification Checked m Analog board frequency response flat within 30 mdB to 8 MHz when checked with setup described m System frequency response flat within 30 mdB to 6 MHz when checked with setup described VM700T Video Measurement Set Service Manual Adjustment Procedure Check the Frequency Response 1 Remove the VM700T top cover to access the adjustments 2 Setthe controls on the gain phase analyzer as needed For the example gain phase analyzer the controls are set as shown in the gain phase analyzer setup
197. e Analog Ref input Check the measurement reading m 700 firmware version 980422 and below 16 mSec to 17 VM700T firmware version 990512 and above 16 mSec to 17 4 27 SDI Option 1 Verification Eye Diagram Application Perform the following procedures to check the SDI Eye Diagram application Eye Diagram Amplitude The amplitude accuracy specification for the SDI Eye Diagram application is Accuracy 5 for signals between 600 mV pp and 1 Perform the following procedure to check the amplitude accuracy of the SDI Eye Diagram application 1 Connect 67 5 MHz 800 mVpp leveled sine wave to the SDI Ch A input Terminate the SDI Ch A input with a 50 precision terminator NOTE If you are using the Tektronix SG 5030 connect the Output Head directly to the SDI Ch A input no cable between the Output Head and the input 2 Press the 700 front panel Measure button and then touch the SDI Eye Diagram soft key 3 Press the VM700T front panel Menu button 4 Touch the Waveform soft key and then select Free Run on soft key is highlighted 5 Press the VM700T front panel Menu button and then touch the Cursors Units softkey 6 Touch the Volt Cursor 1 soft key and then use the front panel knob to position the cursor to the top of the sine wave NOTE It may be necessary to expand the waveform to accurately position the voltage cursors You can e
198. e DSP to keep it from interrupting the A D converter during calibration That signal is removed when calibration is complete The control signals sent between the audio digital and the audio analog board are optically isolated with one exception The CLR signal entering the analog board is inverted to a CLR signal This signal turns on the 2 304 MHz DAC clock when the DAC is operating Five opto isolators isolate the signals between the boards and allow the analog ground on the audio board to float to remain ungrounded from chassis or earth ground Analog board input signals to be isolated enter the board through a buffer The buffer receives its power from the VM 700T The input signals enter through two of the opto isolators each device is a dual opto isolator The signals sent from the isolators are referenced to analog board ground This means that the analog board digital ground and the digital board ground are not the same The other three opto isolators take signals from the analog board and isolate them for output to the digital board These signals associated with the A D converter are applied to a buffer to drive the opto isolators The open collector outputs of the opto isolators are pulled high in case a fault causes the lines to be undriven VM700T Video Measurement Set Service Manual 3 41 Theory of Operation 3 42 Synchronizer Counter Decoder Control Register Master Oscillator and Clock Divider
199. e SDI board NOTE The analog measurements of the VM700T are still usable if the Option 1S diagnostics fail but the VM700T passes the rest of the diagnostics Like the other VM700T user selectable diagnostics the Option 1S diagnostics can be configured to run at power up on demand or in a continuous loop when Option 1S is installed in the VM700T The following procedure provides instructions on how to connect signals to Option 1S in order to perform the full set of option diagnostics The diagnostics do not verify any specifications but they do provide a high level of confidence that the option is working properly Table 6 13 lists the Option 1S diagnostic tests To verify instrument operation to published specifications refer to the SDI Option 1S Performance Verification on page 4 25 VM700T Video Measurement Set Service Manual Troubleshooting Procedures 1 0 SDI SDI Acq Cont Interconnect Interconnect New ed 1 0 Board Controller Channel Board Ribbon cable Channel B SDI Output LTC SSS SDI Specific Hardware Figure 6 66 Option 1S simplified block diagram 1 Connect signals to all of the Option 1S rear panel connectors as shown in Figure 6 67 NOTE The internal power up diagnostics for Option 1S provide the greatest degree of testing for instrument functionality when all rear panel connectors have proper si
200. e both boards at the same time Figure 6 5 shows where the audio option boards are located in the left side card cage Card cage center support Audio Analog board A13 option 40 or A17 option 41 xN ol 55520505200 aaa A12 Audio Processor board 5 0000000000000 gt Front 19 GPIB Interface board 9 c 522202 ER I A20 CPU 1 0 board J with RS 232 ports on rear of J the board Y Leftside ofthe measurement set Figure 6 5 Locating the audio option boards in the left side card cage Required Tools Use the following tools to remove the Option 40 or Option 41 circuit boards m Flat blade screwdriver 3 16 or blade W Pozidrive screwdriver 1X Procedure Use the following procedure to remove and replace the Audio boards 1 Perform the following steps to remove the Audio boards a Remove the left side cover panel refer to Cover Panel Removal and Replacement on page 6 8 b Remove the retaining screw from the card cage center support and remove the center support from the card cage see Figure 6 3 on page 6 10 VM700T Video Measurement Set Service Manual 6 11 Maintenance Option 41 Connector 6 12 Installation c
201. e comes from a 12 bit DAC whose input code comes from a look up table contained in a programmable logic device Outputs from the look up table also control the range switch The input to the look up table is the five bit gain control word from the acquisition controller board Together these components provide a gain range of 0 to 7 75 in steps of 0 25 Dither Generator and Dither data bits from the acquisition controller board can be converted to 64 Dither Amplifier analog levels usually only the first 32 levels are used to effectively increase the resolution of the 10 bit ADC The dither amplifier buffers the processed video signal before passing it to the ADC board where it is digitized Calibration DAC calibration DAC is a precision digital to analog converter used for gain compensation over the analog signal path including the analog to digital converter A calibration switch on each input channel couples the calibration signal onto the signal path at regular intervals The output of the ADC provides calibration information that is stored in a look up table The VM 700T uses the look up table information to maintain its luminance accuracy specification without the need for periodic readjustments Sync Selection The VM 700T gets sync from one of two sources directly from the channel A B or C loop through inputs from the external sync loop through input To maintain a high impedance level for the video loop through inputs th
202. e instrument will be reset to run in the mode selected below overriding current boot switch settings Key Selection NORMAL Start Instrument in Powerup Mode Current Powerup Mode is QUICK START abort this menu and go to the DIAGNOSTICS CONFIGURATION MENU to change it POMERUP DIAGS rrr ne Da Diagnostics start Instrument Q QUICK STARTS serene ht tres Skip Diagnostics start Instrument L LOW LEVEL DIAGS LOOP iie oo Loop on Low Level Diagnostics D HIGH LEVEL DEBUG s ves en nne Start Instrument in HL Debug Mode 5 Do EXTRA Diagnostics start Instrument Reprint 8 Abort Menu Input your selection Figure 5 9 Instrument run modes menu 5 20 VM700T Video Measurement Set Service Manual Adjustment Procedure 5 In the Run Modes Menu use the large control knob to select A Auto Reset and press the Select Line button to activate the selection This restarts the VM700T and runs the full set of internal diagnostics 6 Check that all tests pass as they run If a test fails refer to Diagnostics on page 6 55 for further actions you can take to determine which board or boards may be at fault If you need further assistance contact your nearest Tektronix representative or call Tektronix Customer Service Option 15 Adjustment Procedure Required Equipment Table 5 4 lists the test equipment required
203. e separated to keep ground loop signals and noises from being transferred via the grounding planes of the circuit board Option 41 Audio Analog Board 6 Balanced Input Selector The Audio Analog circuit board A17A1 is identical to the A13 Audio Analog circuit board in parts and operation Option 41 provides an added circuit board A17A2 to do the input channel selection from the three audio inputs The A17A2 circuit board along with the A17A1 A13 circuit board make up the A17 circuit board assembly for Option 41 Selection of the left and right input signal source from one of the three possible inputs of Option 41 is done by a set of relays and a relay selector driver device on the A17A2 circuit board Figure 3 16 shows a simplified diagram of the left input channel switching The left and right selection relay circuits are identical in operation For brevity only the left channel operation is described here VM700T Video Measurement Set Service Manual 3 43 Theory of Operation Three Rear Panel Left Inputs Switching signals From A17A1 i om A XOR B M oro A XOR BH XOR C ci Ct i z Oy A B oo B A XOR B XOR C Nr CH1 Channel input to C A17A1 CH1 COM 02 Relay Selector Driver Figure 3 16 Audio Analog block diagram 3 44 Source Selection Relays The contacts of one relay select between input 1 and input 2
204. e sync selection buffers the selected signal Following the sync selection is an amplifier that returns the video to the nominal one volt level required by the sync stripper circuitry on the genlock board VM700T Video Measurement Set Service Manual 3 5 Theory of Operation DVM Selection and DVM 3 6 The sync stripper needs a negative going Sync pulse To enable the instrument to lock to inverted video the amplifier following the sync selection can be programmed to invert the inverted video selected as the sync source push down the front panel SOURCE A B C button for about one second to invert the video NOTE Video appears on the display in whatever orientation inverted or non inverted it appears at the input connector When you push the SOURCE A B C button only the video used as the sync source is inverted The DVM measures the average picture level APL The VM 700T measures the analog average as the video exits to the filter switch board This analog voltage is converted to a frequency output and sent to the acquisition controller board where it is averaged by a counter The counter output is read by applications that furnish the APL readout on the display Fifteen other inputs to the DVM selection block are selected by two multi plexers The following selections are included BW Outputs of the clamped amplifiers m Offset amplifier m Dither amplifier m Calibration DAC m Video from the filter switch board
205. e tie wraps 2 ea Tektronix part number 346 0120 00 When installed as described on the assembled audio cable the ferrite forms act as a choke to reduce the level of high frequency noise emitted from the signal interconnection cabling VM700T Video Measurement Set Service Manual 6 13 Maintenance Option 48 GPIB Interface Board Removal 6 14 and Replacement Perform the following steps to install the ferrite choke after assembling the cable to the supplied connector 1 Place a cable tie wrap around the cable with the tie wrap end started through the tie binder to form a loop 2 Place both ferrite forms on the cable as shown in Figure 6 8 The parts must be placed as close to the to the connector as possible 3 Slide the loop of the tie wrap over the two ferrite halves and tighten the tie wrap firmly Trim off the excess end of the tie wrap 4 Place an additional tie wrap around the cable behind the ferrite forms to eliminate the possibility of the assembled parts slipping on the cable Tighten the tie wrap on the cable and trim off the excess end un Figure 6 8 Ferrite forms installed on the Option 41 interconnection cable As you face the front of the VM 700T in the operating position the GPIB Interface board A19 is located in a card cage on the right side see Figure 6 5 The GPIB interface option board occupies the second slot above the I O board To remove the GPIB board you mus
206. ection and cleaning page 6 4 m Repackaging the instrument page 6 5 m Removal replacement instructions page 6 6 m VM700T rack mounting instructions page 6 44 m Troubleshooting procedures page 6 49 Servicing Preparation CAUTION The following procedures should be performed only by qualified service personnel Performing these procedures incorrectly could result in damage to the instrument Before you begin to service this instrument perform the following steps m Read the General Safety Summary and the Service Safety Summary at the front of this manual m Read the Operating Information section of this manual m Read the Preventing Electro Static Damage instructions and the Customer Service information on the following pages VM700T Video Measurement Set Service Manual 6 1 Maintenance Preventing Electro Static 6 2 Damage This instrument contains electrical components that are susceptible to damage from electro static discharge Static voltages 1 to 30 kV are common in unprotected environments Table 6 1 shows the relative static discharge susceptibility of various semiconductor classes Table 6 1 Static susceptibility Relative susceptibility levels 1 Voltage MOS and CMOS 100 500 V ECL 200 500 V Schottky Signal Diodes 250 V Schottky TTL 500 V HF Bipolar Transistors 400 600 V J FETs 600 800 V Linear microcircuits 400 1 000 V est Low Power Schottky TTL 900 V
207. ed The output of the Gennum 9000 deserializer U62 for Ch 1 U163 for Ch 2 is routed to the data acquisition system and a data acquisition is performed Each of the 10 bits of the data path is checked for movement and a message is generated to the console for each bitthatis stuck high or low Note that these data bits after they come out of the Gennum part are multiplexed through U35 CHA data CHB Data input VIDEO MUX output Next this video mux output is multiplexed again through U30 coming out of this device as VIDEO OUT 9 0 This is what drives the TTL ECL drivers U139 U140 U141 and U43 for eventual transmission to the Acquisition Controller board The above three tests are repeated for channel B with the same pass fail criteria and test execution constraints There is only one test in this group The SDI board is configured for an eye diagram acquisition The data muxes are setup to pass Channel C data through to the acquisition board and an eye acquisition is performed The 10 data bits are checked for movement and any bits that are stuck high or low are reported to the console If there is no signal on Channel A as determined by checking the signal present locked bits this test will be flagged N A SDI J itter Path There is only one test in this group The SDI board is configured for a jitter acquisition The data muxes are set up to pass Channel C data through to the acquisition board and a jitter acqu
208. ed a clamp and bias level to the clamped input amplifier in each channel The DAC devices receive data and address information from the acquisition con troller board The 3 address bits select the appropriate DAC clamp or bias for channels A B or C while the 8 data bits are converted to the actual clamp or bias voltage Output from the clamped amplifiers is fed to a switching matrix that enables the user to select various combinations of input channels VM700T Video Measurement Set Service Manual 3 3 Theory of Operation Clamped Input Amplifier Channel Selection d f witch Boar Loop Through Inputs Switch 5 A gt Oo Chan A 2 Differential Amplifier oao 1 Chan B TE 2 gt NI 5 y l 2 3 Cal DAC N Clamp and Bias Mode 73 Generator Sync gt Genlock 4 Ex gt Selection Board Sync gt Sync Buffer DVM Selecti vec To coon i Acquisition Control Signals 15 Selection CS From Acquisition Controller Dynamic Offset 4 Generator From Filter gt Switch Board 62 a Offset Variable Dither Amplifier Gain Amplifier Amplifier Possible front panel selections using hardware and software BEA B
209. ed with an indicator to show that the associated voltage is up AII the green indicators should be on for normal operation of the power supply Check that none of the RED indicators are lit If any are on a power supply problem is indicated If the VH housekeeping voltage LED is on and the other green voltage indicators are flashing on and off check the status of the OI over current LED If the OI LED is flashing or on solid there may be excessive loading on the power supply by the VM700T circuitry See Table 6 9 for checks and actions for the various trouble indications VM700T Video Measurement Set Service Manual 6 91 Troubleshooting Procedures Table 6 9 Power supply trouble indicators Indicator Undervoltage LED on Check Supply LED indicators to check for a missing supply voltage Over Voltage LED on Check that all the green Supply LED indicators are off except the VH LED The supply will be in shutdown mode Action Replace power supply using board exchange For information on how to return defective instrument modules to Tektronix for repair see Exchanging VM 700T Modules Turn the master ON OFF switch off and back on to recycle the power supply shutdown control circuitry Check that the power supply operates normally after power is reapplied and the front panel STBY ON switch is turned on If not replace the power supply Over Temperature LED on Check Supply LED indicators to see if an over te
210. edures Table 6 3 VM700T symptoms and corrective actions cont Symptom No waveform display or a Loss of Sync message in waveform mode Screen brightness does not adjust No GPIB Operation No RS232 Operation Possible cause Loose cable connections Incorrect input signal incorrect H sync or V sync signal Corrective action Check cable connections Verify that horizontal and vertical sync signals are being sent Signal too noisy signal noise ratio below required minimum Correctthe cause of low S N ratio signal Incorrect sync source selected Select correct sync source Faulty genlock board A2 Replace the genlock board Refer to Removing and Replacing the Genlock Board Faulty acquisition memory board A18 Faulty analog input board A1 Faulty CRT display module Faulty front panel A10A1 or keypad board A10A2 Faulty display memory SIMM on the CPU board Fault display memory circuit on the CPU board Bad or loose GPIB cable No controller or incorrect controller configuration Faulty GPIB Interface board Incorrect RS 232 cable Replace the acquisition memory board Refer to Removing and Replacing the Acquisition Memory Board Replace analog input board Refer to Removing and Replacing the Analog Input Board Replace the CRT module Refer to Removing and Replacing the CRT Display Replace the front panel keypad board asse
211. eight most significant bits of the 10 bit samples are either all 175 or all 0 If either event occurs Overrange is asserted for that sample Sample Clock 4FSC four times the subcarrier frequency signal from the GenLock board is used to develop the sample clocks SAMPLE CLK and SAMPLE CLK to the ADC and the acquisition clocks CKD and CKD for the acquisition con troller board The clocks to the acquisition system are connected through a 36 pin ribbon cable along with 10 bit data from the A D converter and the Frame Out and Line Out signals VM700T Video Measurement Set Service Manual 3 13 Theory of Operation Filter Switch Board A4 Filter Select and Control Slot 0 Slots 1 5 Output Amplifier The filter switch board performs analog filtering of the video signal Filtering is performed by one of five filters mounted as daughter boards on the main circuit board The video signal is intercepted on the analog input board just after channel selection and then returned for analog processing offset gain and dither Figure 3 4 shows the filter switch board block diagram The filters are NTSC band width limit Chroma bandpass IEEE low pass differentiated step and low frequency noise The acquisition controller board provides inputs to the filter select and control block After decoding these inputs select and control the desired filter Note that only the low frequency noise filter has controllable characteristi
212. ektronix part number 015 0572 00 50 75 converter 50 Q BNC female to 75 Q BNC male Tektronix part number 011 0057 01 1 The example leveled sine wave generator requires TEGAM TM500 or TM5000 series power module VM700T Video Measurement Set Service Manual 4 25 SDI Option 1 Verification Preliminary Setup 4 26 Perform the following steps to setup the equipment for the Option 15 perfor mance verification 1 Connect power to the VM700T and turn the instrument on Verify that the instrument passes all diagnostics as the instrument powers up 2 Press the VM700T front panel Configure button Select Mode Digital if necessary using the Mode soft key NOTE The VM700T must be set to Mode Digital before you can perform the Option 1S performance verification procedures 3 Touch the Configure Files soft key and then touch the Source Selection Digital soft key 4 Highlight the Digital A line using the front panel knob and then touch the highlighted line to cause a box to appear around the current selection 5 Turn the knob to select Auto Detect and then touch the Accept Input soft key 6 Highlight the Digital B line using the knob and then touch the highlighted line to cause a box to appear around the current selection 7 Turn the knob to select Auto Detect touch the Accept Input soft key and then touch the Update amp Exit soft key to exit the configuration file
213. el and measuring the net bias for each switch setting Bias Control Range for each channel VM700T Video Measurement Set Service Manual Checks bias control DAC for range and bit weights Verifies each DAC for independence by changing the other two and monitoring the one being tested to verify that its range and bit weight remain unchanged 6 81 Troubleshooting Procedures Table 6 4 User selectable diagnostics cont Board tested Description 25 Clamp for each channel Filter 26 Times 8 Gain Successful completion of 27 Filter Slot n for slots 0 these tests requires that through 5 the Genlock A2 Acquisition Memory A18 and Analog Input A1 boards be operating correctly indicated bit Checks clamp level DAC for range and bit weights Verifies each DAC for independence by changing the other two and monitoring the one b eing tested to verify that its range and bit weight remain unchanged Measures fast and slow clamp response time by timing a 100 mV C C lamp level change Verifies fast clamping at each possible lamp pulse width Using the ADC two Cal DAC DC levels are measured with x8 gain off two more with iton and the gain is calculated from the ratio of the d S fi T ifferences lot 0 is a bypass path rather than a filter slot These tests include Iter ID and frequency response sub tests he filter ID sub test checks instrument firmware to determine the TV s
214. el difference between channels is 0 2 dB at levels of 50 dBu and greater E Power on the VM700T and associated test equipment and let them warm up for 20 minutes 2 Connect the sine wave generator to the VM700T audio option left and right mini XLR input connectors See Figure 4 6 for an example of cabling NOTE For this connection you may want to use the two female XLR to male mini XLR adapter cables supplied with the VM700T If you do you will need to furnish or fabricate an adapter on the signal generator end 4 15 Audio Option 40 Verification Procedure To Option 40 audio input connectors p Figure 4 6 Option 40 cable connections level accuracy and flatness check Press the Measure hard key select Audio and run the Audio Analyzer measurement Using a known accurate sine wave generator or one verified with an accurate AC voltmeter apply a 120 Hz input to the Audio option at amplitudes gt 20 dBu for example 18 8 2 12 dBu and verify that the level accuracy is 0 1 dB Select at least 6 frequencies and 10 amplitudes over the listed range to test The frequencies and amplitudes you select must be in the ranges listed in Table 4 3 use a signal amplitude level of 70 dBu to test for worst case Table 4 4 shows an example selection of test frequencies and amplitudes Table 4 4 Example test signals for level and flatness test Frequency
215. el timing measurement reading of 37 ns e Remove all cable and terminators from the VM700T VM700T Video Measurement Set Service Manual SDI Option 1 Verification SDI Output Perform the following procedure to check the SDI Output signal 1 2 Connect a 270 Mb 525 line 10046 color bars signal to the SDI Ch B input Connect a one meter cable from the SDI Output to the SDI Ch A input Terminate the SDI Ch A input using a 75 2 high frequency terminator Press the VM700T front panel Configure button Touch the Configure Files soft key and then touch the Source Selection Digital soft key Highlight the SDI Output line using the front panel knob and then touch the highlighted line to cause a box to appear around the current selection Turn the knob to select Channel B and then touch the Accept Input soft key Touch the Update amp Exit soft key to exit the configuration file Press the front panel Measure button and then touch the SDI EyeDiagram soft key Press the front panel Menu button and then touch the Measure soft key Touch the following soft keys if necessary to turn the measurements on soft keys will be highlighted Meas Box Eye Amplitude Rise Fall Times and Rise Time Adjusted NOTE For the SDI Output check the Average function must be turned off Use the front panel Average button to turn off the Average function 10 Check that the Amplitude readout is 7
216. ement monitor when supplied by Tektronix has been aligned for proper operation in the VM700T but Trace Rotation a monitor control and vertical and horizontal centering and size CPU board controls may be needed to align the replacement display The final procedure is to set the power up display intensity and calibrate the touch screen Test Equipment Required m Non metallic flat blade adjusting tool Tektronix part number 003 1364 00 Adjusting the Display Monitor 1 Power off the instrument disconnect its power cord and remove the left and right side covers 2 Reconnect power to the VM700T press and hold the Waveform button when you turn the power on After the instrument beeps twice release the button and let it complete its power on initialization The waveform graticule is the default display at power on 3 Look at the lower left corner of the waveform graticule It should form a 90 degree right angle If not adjust the Trace Rotation control located on the left side of the monitor chassis to level the form graticule trace across the screen 4 Turn the VM 700T off VM700T Video Measurement Set Service Manual Adjustment Procedure 5 Press and hold the Menu button while turning on the power After the VM700T beeps twice to acknowledge the startup mode release the Menu button The VM 700T then initializes directly into the Low Level Diagnos tics Interface with the VM700T startup menu as shown in Figure 5 2
217. en you can recalibrate it Use the following procedure to calibrate the touch screen 1 Switch off power to the measurement set at the front panel 2 Press and hold the Menu button while turning on the power After the measurement set beeps twice to acknowledge the startup mode release the Menu button The measurement set then initializes into the Low Level Diagnostics Interface with the VM700T Startup Menu see Figure 2 2 VM700T Video Measurement Set Service Manual Operating Information Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu Calibrate TOUCH PANEL INTERFACE Reprint 8 Abort Menu Input your selection Figure 2 2 VM700T Startup menu 3 Use the large control knob to highlight the T in the Calibrate Touch Panel Interface line of the VM700T startup menu Press the Select Line button to make the selection to calibrate The first touch screen calibration instructions are then displayed as shown in Figure 2 3 Follow the written directions Pressing AUTO aborts the calibration process and returns you to the startup menu Pressing any other button stores the setting in NVRAM and brings up the next touch screen calibration menu After making the adjustment
218. ency with the Horiz Sync control The output of the PLL is further amplified to drive the horizontal deflection yoke Width of the display on the CRT is set using the Horizontal Width adjustment The Horiz Position control adjusts the fine position of the active picture area within the raster scanned width VM700T Video Measurement Set Service Manual Theory of Operation High Voltage high voltage supply provides the CRT anode voltage the focus voltage and the 55 V and 100 V sources The main focus voltage is set by the FOCUS potentiometer Dynamic focusing optimizes the edge focusing of the CRT The dynamic focusing waveform is shaped to produce the best edge focus in conjunction with the setting of the FOCUS pot for best overall focus Trace Rotation The Trace Rotation circuit drives a separate deflection coil on the neck of the CRT The adjustable voltage from the trace rotation potentiometer provides an overall adjustment range for trace rotation of approximately 3 4 VM700T Video Measurement Set Service Manual 3 31 Theory of Operation Power Supply A15 The power supply is composed of a primary rectifier the inverter switching circuit 12 V and 15 V regulators alarm sensing circuitry that monitors for overvoltage overcurrent and over temperature conditions and the alarm logic circuitry that shuts down the inverter switching circuitry in the event of a problem simplified block diagram is shown in Figure 3
219. ent EMI fan filter bm SN B030100 and above only Blank panel removed for access to separate fan nut Fan finger guard SN B029999 and below only 5 SS amp VGA A21 board removed for access to separate fan nut Figure 6 26 Removing the cooling fan 6 42 VM700T Video Measurement Set Service Manual Maintenance 2 Replace the cooling fan by performing step 1 in reverse order CAUTION Incorrect installation of the fan assembly will result in overheating and possible damage to the measurement set NOTE Reinstall plastic retainers to hold the fan wire harness to the bottom of the left card cage Reconnect the VGA cable to the fan housing with a cable tie When reinstalling the fan make sure you have the fan positioned so that the air flow is out of the VM 700T VGA Connector Board Use the following procedure to remove and replace the Connector board 1 Perform the following steps to remove the Connector board a d Remove the instrument cover panels refer to Cover Panel Removal and Replacement on page 6 8 Remove the attaching hardware for the VGA Connector board from the rear of the VM700T see Figure 6 26 Pull the VGA Connector circuit board away from the fan housing and disconnect the VGA ribbon cable from the connector on the rear of the Connector board Remove the VGA Connector board from the VM700T
220. ent m The module has been modified by the customer m The module has been modified to the customer s specifications by Tektronix In these cases Tektronix invoices the full catalog price of a replacement module Call your local Tektronix field office for further information Customer Service Outside the U S Customers outside the United States should contact their local Tektronix sales subsidiary or distributor for details on servicing the VM 700T VM700T Video Measurement Set Service Manual 6 3 Maintenance Inspection and Cleaning 6 4 AN Cleaning CAUTION Cleaning and general maintenance of the VM 700T should be performed only when the instrument is powered off and the power cord removed from electrical mains The instrument should be cleaned often enough to prevent dust or dirt from accumulating Dirt acts as a thermal insulating blanket that prevents effective heat dissipation and can provide high resistance electrical leakage paths between conductors or components in a humid environment Use the following tools to clean the instrument W Clean nonabrasive lint free cloth m Nonabrasive liquid glass cleaner m Isopropyl alcohol Static free vacuum cleaner with small brush attachment Cleaning the Exterior Clean the dust from the outside of the instrument by wiping with a soft cloth You may use a brush to remove dust from around the selector buttons knobs and connectors Hardened dirt may be remove
221. ent Set Service Manual Theory of Operation Audio Processor Interface Address Decoders Bus Buffers Address Buffers The Audio Processor Interface consists of address decoders bus buffers and address buffers Address lines are decoded to provide the various control bits used throughout the audio option boards Several address decoders are used One decodes data intended for the Audio Processor board another decodes the P X and Y memory program memory and the X data and Y data memories A third decodes the control registers on the Audio Processor board and the interrupt control signals for both the CPU and the The bus buffers are enabled during bus to bus accesses They are disabled to isolate the busses when bus to bus accesses are not being done address buffers are unidirectional devices that feed the Audio Processor address to the DSP address bus Interrupt Generator Status Port Interrupt Generator Data Buffers A function of this 32 bit control register is to control interrupts for the DSP digital signal processor It consists of an interrupt generator data buffers and read write registers that hold the data for access when needed The interrupt generator contains the interrupt control lines for the DSP The interrupts are generated by audio data When enabled left channel audio data and right channel generate separate interrupts to keep the channel data separated for processing There are
222. eps Low Level To Low Level Low Level Diagnostics Diagnostics Diagnostics VM 700T Startup Menu Diagnostics Diagnostics Calibrate enu Help Touch Panel Menu Interface Power Up Error Log Set Diags Mode Utilities Powerup Mode PowerUp Diags Instrument Utilities Run Modes Set Diagnostic Instrument Powerup Mod NVRAM owerup Modes Utilities List Intensity Diagnostic Front Panel Reprogrm Quick Start Set Low Level Diags Console Buttons Firmware Date Code Baud Rate Low Level Diags Loop Instrument High Level um ID Number Debug Reset 9W Option Key Auto Reset aimi Use Abort or press the Auto button to back up the tree to the VM700T Startup Menu Figure 6 31 VM700T diagnostics menus overview VM700T Video Measurement Set Service Manual 6 57 Troubleshooting Procedures From VM700T Low Level Diagnostics Startup Menu Main Board Main Board CPU Diags Display Diags Low Level Diagnostics Main Board Front Panel Interface Diags 1 0 Board Diags Overall Run Mode Power Up Auto Reset Custom Sequence CE Mode Result Display Mode Result Logging Mode Build a Sequence CPU Diags Display Diags Front Panel 1 0 Diags Audio Diags Test List Test List Diags Test List Test List Test List Use Abort or press the Auto button to back up the tree to the VM700T Startup Menu GPIB Diags
223. equency response On the example Gain Phase Analyzer press Display Superimpose Store and Recall A 13 Select 1 select Input Source and select B on the VM700T for channel B input 14 Move the cable and terminator to the channel B feedthrough connectors on the rear panel of the VM700T 15 Check that the channel B response curve matches the stored channel A response curve within specification If the response curve for channel B does not match the stored channel A trace adjust R304 and 138 if necessary to match the the stored trace VM700T Video Measurement Set Service Manual Adjustment Procedure 16 Select C on the VM700T for channel C input 17 Move the cable and terminator from the channel B connectors to the channel C connectors 18 Check that the channel C response curve matches the stored channel A response curve within specification If the response curve for channel C does not match the stored channel A trace adjust R276 and R146 if necessary to match the the stored trace 19 Remove the gain phase analyzer cable from the channel C connectors On the VM700T select A for channel A input 20 On the gain phase analyzer return to the main menu Press Recall A to remove the stored trace C922 affects this area ofthe curve on all 3 channels A Adjust C922 for best flatness on all channels B Bandpass is too low Adjustthe Input C for the affected channel
224. er Tektronix part number 003 1364 00 1 Youcan measure the jitter of your clock source using the SDI Eye Diagram application Select Free Run mode on Filter 10 Hz Average mode on and Average set to 4 The horizontal width of the rise and fall traces at the 0 mV level must be less than 150 ps as measured with the timing cursors Adjusting the J applica Tektronix TG 2000 Signal Genera tion tion Platform with a BG1 module must use the Clock Out connector VM700T Video Measurement Set Service Manual 5 21 Adjustment Procedure 5 22 Preliminary Setup Prepare the equipment as listed below to perform the adjustment procedure 1 Remove the right side cover retaining screws on the VM700T as shown in Figure 5 10 Leave the side cover closed In some steps of the adjustment procedure you will slide the cover back to access internal components 2 Connect the power cable to the VM700T and then power on the VM700T measurement set 3 Watch the power up text to verify that the VM700T passes all diagnostics as the instrument completes its power up procedure 4 Press the front panel Configure button 5 If necessary set the VM700T to Digital Mode using the Mode soft key 6 Touch the Configure Files soft key and then touch the Source Selection Digital soft key 7 Use the front panel knob to highlight the Digital A line and then touch the highlighted line to cause a box to appear around the current
225. er service information and illustrated step by step procedures for removing and replacing the field replaceable modules of the VM700T Installation instructions for the rack mounted instrument are in this section Troubleshooting and diagnostic information is provided to help you troubleshoot the VM700T to isolate a faulty circuit board module for a module exchange repair Options has a listing with a short description of the available options for the VM700T Replaceable Electrical Parts List refers you to the Replaceable Mechanical Parts List for the list of replaceable electrical parts Diagrams provides an overall block diagram and a circuit board interconnec tion diagram to assist in faulty module isolation procedures Replaceable Mechanical Parts List has exploded views and gives the lists of the replaceable mechanical parts to aid in locating a replacement mechanical part The assembly Tektronix part numbers are also included in this list as a convenience VM700T Video Measurement Set Service Manual xvii Preface xviii VM700T Video Measurement Set Service Manual Specification The performance limits in this specification are valid with the following conditions This instrument must have been calibrated adjusted at an ambient tempera ture between 4 20 C and 430 The instrument must be in an environment with temperature altitude humidity and vibration within the operating limits described in this specificatio
226. ere are stored patterns selected by the four bits from the control register are stored The selected pattern provides gating for input signal clamping and the DVM The gating information drives a triple timer counter U6 The ATRIG BTRIG and CTRIG outputs from the triple timer counter drive a one shot multivibrator on the analog input board Trigger pulses are generated for each line where clamping is to be applied These pulses determine the point on a line where clamping begins other control lines on this board control circuitry on the analog input board that sets the clamp level and duration VM700T Video Measurement Set Service Manual Theory of Operation CPU SYSTEM BUS 24 31 af 0081 HH Do ADDRESS CONTROL DECODER DATA ADDRESS BUFFER BUFFER 2 TTL TO ECL 2 Apc BD0 31 CONTROL 16 BD16 31 CONTROLLER ASIC OE BA10 15 SEQUENCER ADDRESS 7272777 NNNNNNN BUFFER FRAME LSYNC BA0 15 ACQUISITION gt COUNTERS CONTROL BOARD gt y Y gt SEQUENCER CONVERTER P CLR ADDRESS FRAME h N REGISTER LINE SCLK js OVR RNG Y DATA CONTROL SEQUENCER gt STATIC RAM 16K X 32 u ADDRESS SC PORE Y LK SMA0 13 og DATA LATCH 13 TO ANALOG Eam dd INPUT BOARD lt COUNTERS 32 ADDRESS COUNTERS CONTROL TRIGGER RAM za im UM ACQUISITION SECTION S
227. es Power up and Interactive Each diagnostic consists of a series of tests and each series is organized into test families When running individual diagnostics you have two display choices Power Up Mode and Interactive Mode These are described below To run a diagnostic touch the icon representing that diagnostic in the directory window When each diagnostic starts you are prompted to select a run mode from the soft keys at the bottom of the screen as shown in Figure 6 52 The available choices are Power up Mode and Interactive Mode GPIB Diagnostic Select Run Mode Powerup Interactive Mode Mode Figure 6 52 Select run mode the high level diagnostic initial menu Power up Mode Runs the selected diagnostic the same way it would run during power up Power Up Mode when selected displays the Change Run Mode soft key Touching the Change Run Mode soft key returns you to the SELECT RUN MODE screen diagnostics can be bypassed or configured to run in normal power up mode When configured to run all the tests for that diagnostic are run completely through and the display returns to the initial Diagnostic menu unless an error is found VM700T Video Measurement Set Service Manual 6 75 Troubleshooting Procedures Power Up Mode displays a line for each family of tests that passes If any of the tests within the family fail the program halts at the failed main test and shows the test b
228. es of continuing the testing looping on the selected test block re running the test block or changing the run mode for the testing program as shown in Figure 6 53 Selecting to continue resumes the testing and runs the next main test When all the tests within a diagnostic routine have been completed and the Continue soft key is selected the Select Run Mode screen is displayed 6 76 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Test meas t units min max result VMIPC Register Pass Readable Pass Writalbe Pass Bit 0 Control Pass Bit 1 Control Pass Bit 2 Control Pass Bit 3 Control Pass Bit 4 Control Pass Bit 5 Control Pass Bit 6 Control Pass Bit 7 Control Pass Continue Loop On Rerun Change Test Test Run Mode Figure 6 53 Interactive run mode menu after running first main test DiagsLoop You may at times want to run the user selectable diagnostics continuously Continuous or looped diagnostics are useful if you are looking for intermittent errors The DiagsLoop application is located in the VM 700T Diagnostics directory DiagsLoop repeatedly runs the diagnostic routines selected in the Diagnostics Selection file DiagsLoop displays the same level of information as the Power Up Mode of individual diagnostic execution but DiagsLoop does not pause when failures occur Results from all failed tests are written to the Diagnostic Err
229. ese modes are accessed by powering up the instrument with the indicated button s held in The instrument will beep twice and recognize the mode about 5 seconds after power up after which the buttons must be released NOTE The Boot Switches MUST be in their Factory Default position ALL CLOSED to access these modes POWER UP MODES BUTTON S TO HOLD IN QUICK START INSTRUMENT Waveform RUN STARTUP MENU Menu REPROGRAM INSTRUMENT Display amp Waveform amp Auto Press Any Key to Continue Figure 6 39 Special power up boot modes Diagnostic Utilities diagnostic utilities include selections for viewing or clearing the error log clearing the file system NVRAM and CPU NVRAM reprogramming the Flash ROM with the appropriate software and uploading programs showing the firmware date codes finding the instrument ID number and resetting the Option Key Reprogramming the Flash ROM will only be used for actually upgrading the firmware and requires the appropriate programming and upgrade software disks and a personal computer connection to the parallel printer port Resetting the option key should only be needed if the VM700T does not boot up after a firmware upgrade Its use requires knowing the authorized Option Key for the instrument VM700T Video Measurement Set Service Manual 6 65 Troubleshooting Procedures Accessing the Diagnostic Utilities To access the diagnostic utilities perform the follo
230. esented in integer hexadecimal or engineering scientific notation If a value is not appropriate the field is filled with one of the following Lu no value e underrange indicator gt overrange indicator unit Where appropriate a description of the units of the measured value otherwise filler chars The minimum acceptable value for a passing result The maximum acceptable value for a passing result result In general Pass or FAIL Itcan also be one of the following NA not applicable not tested Because a rigidly formatted output excludes much useful information any main or sub result line can have associated with it one or more lines of indented commentary Whereas sub result lines are indented one level of indentation from their associated main results comments will be indented two levels from their associated main results whether they are actually associated with the main result or the sub result VM700T Video Measurement Set Service Manual Troubleshooting Procedures Diagnostics Menu Overview An overview of the VM700T Diagnostics Menus is shown in Figure 6 31 and Figure 6 32 Figure 6 31 illustrates the various configuration menus and utilities that are available in the diagnostics routines Figure 6 32 illustrates the low level diagnostic tests and the various configura tion menus for setting up and running the diagnostic tests Press and Hold Menu Button at Power On release it after two be
231. f the digital hardware Passing the diagnostics is part of the performance verification procedure Hold down the Menu hard key when you power up the instrument After about 5 seconds release the Menu hard key In the VM700T Startup Menu shown in Figure 4 1 select R Instrument Run Modes Menu and press the Select Line hard key to display the Run Mode Menu shown in Figure 4 2 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu Calibrate TOUCH PANEL INTERFACE Reprint 8 Abort Menu Input your selection Figure 4 1 VM700T Startup Menu VM700T Video Measurement Set Service Manual 4 1 Performance Verification Checking for Soft Errors 4 2 In the Run Modes Menu select A Auto Reset This restarts the measurement set and runs the full set of internal diagnostics Check that all tests pass as they run If a test fails refer to the appropriate text in the Maintenance section for further actions you can take to determine which board or boards may be at fault Low Level Diagnostic Interface knob moves cursor Select Line inputs selection INSTRUMENT RUN MODES MENU The instrument will be reset to run in the mode selected below overriding
232. f the problem Attempt to make the determination of whether the instrument is out of calibration or if there has been a component failure Once the type of failure has been determined identify the functional area most likely at fault 4 Visually inspect the suspect assembly for obvious defects Most commonly these will be broken or loose components improperly seated components overheated or burned components chafed insulation etc In the case of overheated components determine the cause of overheating and correct the cause before reapplying power 5 Remove defective modules and exchange them with the factory Refer to Removal and Replacement Instructions on page 6 6 Refer also to Customer Service on page 6 3 for information on the board exchange repair service WARNING High voltages are present inside the VM 700T chassis These voltages can cause serious injury Leave all service procedures that require removing instrument covers to qualified service personnel Troubleshooting the VM 700T is a matter of following a logical series of steps that isolate a problem to a specific system module such as a circuit board power supply or display monitor After isolating the problem repair consists of replacing the faulty module and checking the instrument for correct operation VM700T Video Measurement Set Service Manual Troubleshooting Procedures Some VM700T faults can be isolated to just one system module Correcting these
233. faulty board s may be exchanged to make a repair Board level audio option faults can be isolated by following the steps shown in Figure 6 63 The Audio Processor board has no test points or adjustments Troubleshooting this board consists of running its diagnostics If the board passes the diagnostics it is operating correctly but if it fails it must be replaced Diagnostics are also used to verify the Audio Analog board performance However isolating a diagnostic failure to a fault on this board also requires performing the additional checks shown in Figure 6 63 Figure 6 64 shows the Audio Analog board locations for the checks listed in Figure 6 63 If after performing the checks listed in Figure 6 63 one or both of the audio option boards appear to be faulty arrange to return them to Tektronix Customer Service for repair Refer to Option 40 and Option 41 Audio Boards Removal and Replacement on page 6 11 for information on removing and replacing the audio option boards in the VM 700T Enter diagnostics menu Run Does not pass Audio Analog diagnostic diagnostics Run Bad Audio Processor Audio P rocessor diagnostics board Does not run Passes Bad Bad Perform checks Audio Analog or Audio Analog checks Audio Processor board board Check F1 F2 check DC DC converter 15 V and 5 V check oscillator output pin 2 U53 Figure 6 63 Procedure for troubleshooting the aud
234. ff remove the three top cover holding screws found at the rear of the instrument and slide the top cover panel back enough to expose the genlock board just behind the CRT module Power on the instrument and allow it to warm for 20 minutes if not already warmed For dual standard instruments select either NTSC or PAL mode as needed for the VCO being checked This may be done by pressing the Measure hard key then the Video Standard soft key to identify the applied composite video signal source Then press the Waveform hard key to return to the Waveform mode Selecting the TV standard in this manner is temporary and the configuration returns to match that set in the Video Source file at the next power on Alternately you may use the Configure menus to set the Video Source file for the TV standard you have applied to the channel Connect the DVM plus lead to TP 86 on the Genlock board and the minus lead to chassis ground Check that the voltage is about 0 V 0 V 250 mV The VM700T must be locked to the external input signal NOTE If the VM700T meets the limits described skip step 8 and go to step 9 Adjusting the VM700T unnecessarily for example to get a better reading on a calibration result that is within limits can introduce errors into a functional instrument Adjust the VCO adjusting screw for the TV standard you are checking either NTSC or PAL for a DVM reading as close as possible to 0 V 0 V 250 mV or bet
235. following steps to check Jitter application at 270 Mb 580 Hz a g h Adjust the digital television signal generator for a jitter frequency of 580 Hz and a jitter amplitude of 2 ns on the signal output Press the VM700T front panel Menu button Select Filter 1 KHz using the Filter soft key Touch the Rescale soft key and then touch the Cursors Units soft key Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 580 Hz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 7 4 to 15 4 dB Check that the Timing p p readout is 1600 to 2600 ps Check that the Alignment p p readout is 700 to 1500 ps 3 Perform the following steps to check the Jitter application at 270 Mb and 15 kHz a Adjust the digital television signal generator for a jitter frequency of 15 kHz and a jitter amplitude of 2 ns on the signal output Touch the Rescale soft key and then touch the Cursors Units soft key Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 15 kHz as read in the readout Check that the Spectrum Cursor 1 amplitude readout is 2 4 to 8 4 dB Press the VM700T front panel Menu button Select Rate Line using the Rate soft key Touch the Cursors Units soft key Touch the Spectrum Cursor 1 soft key and then use the front panel knob to position the cursor to 15 kHz as read in the readout
236. for the external clock input to the DSP The communication ports handle parallel data flow between the DSP and the CPU the Host Port and serial data flow to the D A converters and control registers on the analog board One of the communications ports allows commu nications between the DSP and the CPU without having to do a bus request bus grant operation Another port is divided into two serial ports one for serial communications and the other is the synchronous serial interface This register accepts serial data from the ADC on the analog board and converts it to parallel data for the DSP or the CPU A serial to parallel converter converts the serial data from either the ADC or the DSP generated for diagnostics to a 24 bit parallel data word used by the DSP If the DSP is set to generate interrupts when audio data arrives it must service the interrupts in a service routine At the same time the CPU can be trying to read or write data to the same address space being used by the DSP The DSP always gives up its bus to the CPU but this can cause a problem To avoid this bus sharing problem there is circuit that prevents CPU access to the bus during the data interrupt service routine The P program X data and Y data static RAM is composed of 18 25 ns devices Each RAM is 4 bits wide so six memory chips are used to make up the 24 bit word Each pair of chips accessed by the same write enable signal corresponds to one 8 bit byte E
237. form display or the vector display for analysis of that line Auto Mode Auto mode makes standardized video measurements automatically including those specified in the RS 250B EIA 250C NTC 7 and RS 170A video signal standards You can select the limits used on the measurements to determine out of limits conditions The measurement set generates a caution or alarm message if a measurement falls outside the selected limits You can select the format for the auto mode measurement reports and schedule the report printing times Analog Digital Mode If your measurement set has Option 15 installed the VM700T resembles two Option 1S Only separate instruments in one package one analog and one digital You can switch between the analog and digital functions by selecting Digital Mode or Analog Mode from one of these locations the Configuration menu two locations the Measure menu or through remote control NOTE To access any of the functions of Option 15 you must set the VM700T to Digital Mode To access any of the analog measurement applications of the VM700T you must set the VM700T to Analog Mode When you switch between Digital Mode and Analog Mode the operation of the front panel buttons does not change except for the following five buttons Waveform Vector Picture Measure and Auto The Waveform and Picture buttons access the SDI Waveform and the SDI Picture applications respectively The Vector button accesses the SDI Lightning
238. from the CPU board at J9 b Disconnect the multiconductor square pin connectors going to the display monitor J7 and the rear panel connector 176 c Unplug the circuit board using the ejector tab to release the board from the main interconnection board When the circuit board 15 loose slide it out of the card cage Check that the standoff on the CPU board clears as you remove the board Loosen screws 2 slide to the left then remove Figure 6 9 Loosening the screws on the right card cage retainer 6 16 VM700T Video Measurement Set Service Manual Maintenance Acquisition Memory board gt f ec of J 7 Display Monitor connector J 9 Front Panel board connector Figure 6 10 Location of right card cage circuit boards 3 Perform the following steps to replace the CPU board a Guide the board onto the bottom card cage track and slide it into the card cage connector b Align the circuit board connector pins with the main interconnection board connector and press firmly to seat the connector c Reinstall each of the three cables ensuring that they are firmly seated 4 Perform the following steps to replace the right side card cage retainer a Install the card cage retainer by first inserting its upper tabs through the chassis slots Complete the installation by guiding the retainer slots carefully over the circuit board locator tabs
239. g Board A13 Input Amplifiers Signal Input The following paragraphs discuss the Audio analog board Refer to Figure 3 15 as you read the discussion This section discusses the channel 2 right channel input amplifier but the channel 1 left channel input amplifier circuitry and function is the same The input amplifiers are labeled on the board s back panel The channel 2 analog signal enters the board through a 3 pin mini XLR connector on the VM 700T back panel This connector is a balanced differential input VM700T Video Measurement Set Service Manual 3 37 Theory of Operation Calibration DAC Control From Processor Gain amp Offset CAL orto Serial Data LEFT INPUT Out Balanced CAL DE Input Attenuator SELECT SELECT RIGHT 0 10 20dB 0 10 20dB INPUT Balanced CAL Differential 3 Pole j Input ADC Input NORM Attenuator Amplifier Fitter SELECT SELECT 0 10 20dB 0 10 20dB Master 18 432 MHz Oscillator divide by 64 48 kHz COM L R divide by 3 1 divide by 8 2 304 MHz 3 072 MHz lt CONTROL e Relay Control Buffers Registers DATA Figure 3 15 Audio Analog block diagram 3 38 VM700T Video Measurement Set Service Manual Theory of Operation NOTE On option 41 boards the anal
240. gnal connected If there is a signal the diagnostic merely reads the time code and prints it to the console after flagging the test as PASS since we have no means of comparing the timecode againsta known reference to decide if it is correct we merely show it to the user and let them judge the correctness Audio Receiver The audio receiver chip is a crystal 58412 and its functions are all hardwired on the board and thus not amenable to manipulation by the diagnostic program The diagnostic proceeds as follows Data Validity Flag There is a 3 bit field in the device which is used to reportthe status ofthe data This value is read and displayed and can have the following meanings for details please refer to the 58412 data sheet OK 0 Data is valid VALFLG 1 Validity Bit High in data stream CONFLG 2 Confidence Flag SLIPPD 3 Slipped Sample CRCERR 4 CRC Error PARERR 5 Parity Error CODERR 6 Bi Phase Coding Error NOLOCK 7 No Lock Valid Data Mvmt If the data validity flag is NOLOCK then it means there is no signal and the second test is bypassed i e flagged N A Otherwise data acquisition is performed and the diagnostic checks all 10 bits to verify that they are all toggling If they are not then the diagnostic generates a message to the console for each bit that is not toggling Spurious Data Mvmt The third test is run only if there is no valid data since in that case the chip is supposed to output a data
241. gnals connected to them When these signals are not present the diagnostic tests that require input signals will report N A not applicable 2 Press the front panel Measure button and then touch the Diag soft key TG2000 DVG1 270 Mb 525 line or 625 line color bars signal TG2000 AVG1 NTSC or PAL black burst signal Terminator 75 Cable connection AM70 48 kHz sampling professional or consumer format SDI Output 1 kHz tone at full K amplitude 0 dB LTC generator any LTC signal at normal rate Time Code Figure 6 67 Signal connections for performing Option 1S diagnostic tests VM700T Video Measurement Set Service Manual 6 105 Troubleshooting Procedures 3 Rotate the front panel knob until you locate the SDI Diagnostic soft key 4 Touch the SDI Diagnostic soft key to access the SDI diagnostic routine 5 Touch the appropriate soft key to select the diagnostics run mode type Power Up or Interactive NOTE Diagnostics performed from the Measure menu offer two modes Power Up and Interactive In Power Up mode the diagnostics display a one line header for each test being run Should the diagnostics encounter an error the measurement set waits for user acknowledgement In Interactive Mode the diagnostics display more detail about each test being performed Before starting the next test in the list the measurement set waits for user acknowledgement 6 Observe the displayed di
242. he four cables out through the hole in the chassis VM700T Video Measurement Set Service Manual 6 21 Maintenance 6 22 lt 9DIRearPanellnterface assembly A23 A 2nd hole Dress SDI ZS CPU A5 Right side board Figure 6 13 Installing the SDI Rear Panel Interface A23 assembly 2 Perform the following steps to replace the SDI Rear Panel Interface assembly a Position the SDI Rear Panel Interface assembly at the rear of the measurement set Slide all four cables through the second hole from the bottom on the rear panel as shown in Figure 6 13 b Secure the SDI Rear Panel Interface assembly to the rear panel using the four retaining screws c Slide the CPU A5 board halfway out of the measurement set d Lay the SDI multicolored ribbon cable on the CPU A5 board as shown in Figure 6 13 e Reinstall the CPU board VM700T Video Measurement Set Service Manual Maintenance f Plugin the three coaxial cables at J7 J8 110 See Figure 6 12 on page 6 21 for the proper cable connections Plug in the multicolored ribbon cable at J5 h Install the card cage retainer refer to step 4 on page 6 17 i Install the cover panel refer to Cover Panel Removal and Replacement on page 6 8 Analog Input Board Removing and replacing the Analog Input board 1 consists of removing the Removal and top cover removing four wires and two ribbon cables and rem
243. he input of the A D converter The clamping circuit holds the input signal swing to approximately 4 4 volts peak positive or negative This circuit is actually a 150 KHz low pass filter This filter is a 3 pole Bessel type circuit with exceptional phase performance VM700T Video Measurement Set Service Manual Theory of Operation A D Converter Audio Board Control Opto Isolators The A D converter is a delta sigma type oversampling converter running at 64 times the required output frequency In this circuit the 150 low pass filter circuit at the input of the A D converter provides anti alias protection The analog data applied to the inputs of the A D converter is processed by the converter and output as serial digital data The left right channel data is controlled by the L R signal and alternated in the data stream A D Converter Self Cal The CAL signal applied to the A D converter causes a self calibration on the falling edge of the signal During the self cal time the A D converter checks the DC offset on its analog inputs The offset is stored in a register and subtracted from the data sent from the converter This operation zeros the internal offset of the converter and any offset generated by the operational amplifiers or any other DC offset in front of the inputs Up to 250 mV offsets can be removed but the usual offsets are not more than 10 mV During the Self Cal offset calibration a signal is sent to th
244. he shared and private RAM space It is important that the VM 700T processor not be blocked from accessing the shared space so it may communicate with the GPIB processor In normal operation when the VM 700T processor request access the Dual Port RAM controller grants it access However as long as both processors are making accesses they will be alternated so that the GPIB processor is not blocked During normal operation communications between the two processors take place through the shared RAM and the IPC register The IPC register allow either processor to set an interrupt flag to the other processor When an interrupt occurs the inter processor communication is written to buffer then the other processor is interrupted to let it know a message is ready When the interrupt has finished the interrupted processor accesses the data to complete the communica tion A second type of access occurs in the debug mode There is a debug window that allows the VM 700T processor to see all 16 Mbytes of the 24 bit addresses of the GPIB processor Access by the VM 700T processor through the debug window halts the GPIB processor The GPIB processor relinquishes control of its address bus and the VM 700T processor takes control The GPIB processor memory decoding circuitry is used by the VM 700T processor to see the address space so the debug window can be used to test most of the GPIB hardware An exception to this is the GPIB processor interrupts The VM 70
245. his phone number 1 800 833 9200 Customer service personnel will direct your inquiry to the proper support group Exchanging VM700T Modules If you call for a module exchange you must supply the instrument serial number the firmware version number accessed by pressing the Configure button and the module s complete part number to ensure receiving the correct replacement If the module you request is in stock it will usually be sent to you the same day After you receive the replacement module the faulty module must be returned immediately to Tektronix using prepaid common carrier freight Use the packaging material from the replacement module and the furnished shipping label to prepare the faulty module for shipment Ship the faulty module to Tektronix Inc Customer Service Materials M S 58 185 PO Box 500 Beaverton Oregon 97077 0500 Tektronix charges a standard fee for each out of warranty module exchanged This fee will be quoted when you request the exchange module If the faulty module is not received at the above address within 30 days of your request of an operating exchange module the full catalog price of the module will be invoiced If your module has been damaged or modified in any of the following ways it is not eligible for exchange m The module is damaged during repair attempts by personnel other than Tektronix Representatives m The module is damaged through improper use or connection to incompatible equipm
246. ial ECL levels terminated by 100 Q resistors ASYNC SET and SYNC RESET are outputs controlling the ADC board The FIFO first in first out consists of register files and a controlling device The controller makes the synchronous register files behave as a FIFO file This block is the control and timing center of the Acquisition system It handles static RAM access arbitration CPU dual porting state machine instruction interpretation CPU handshaking the real time control FIFO control Min Max control static RAM control and address sequencing for these RAM The acquisition control clock circuit crystal oscillator running at 20 000 MHz Various delayed versions of it are derived by a delay line The clocks are used in the acquisition ASIC for accurate timing of the control activities One clock output is fed to the controller section Because the Acquisition Controller board has its own 20 MHz clock it is independent of the CPU microprocessor the CPU microprocessor interface is asynchronous into the acquisition section of the board The data bus interface controls connection between the CPU data bus and the acquisition data bus to allow static RAM accesses The acquisition memory consist of sixteen 64 K x 4 bit fast 25 ns or lower access times static type RAM in two rows of eight devices with 17 total address bits and 32 bit wide data bus The min max ASIC keeps a running record of the minimum and maximum video data read from the FI
247. ifies it Acquisition Memory A18 Successful completion of 10 FIFO Checks that data moves through the FIFO without overflow even with these tests requires that processor bus contentions Genlock 2 Controller portion of Acquisition Memory A18 be operating correctly Load Looping Checks that acquisition state machine can be programmed to write the contents of temporary store into acquisition memory locations and that it can process acquisition program GOTO instructions 12 Optional Hardware Pass indicates hardware present and working NA indicates hardware not available 6 80 VM700T Measurement Set Service Manual Troubleshooting Procedures Table 6 4 User selectable diagnostics cont Board tested Description External Triggers Long Acquisitions Checks that Controller trigger RAM can be used to recognize when certain bits in the ADC data stream are set Causes signal interrupts that are counted by the Controller s 5100 5101 5102 counters Runs long acquisitions to verify interaction of Controller and Acquisition state machines Sample Dropping Tests involving the Calibration DAC require that the Analog Input A1 board be operating correctly Analog Input A1 Successful completion of these tests requires that the Genlock A2 and Acquisition Memory A18 boards be oper ating correctly DC Paths 14 15 ADC A3 16 Mode Checks Output latches in all
248. ift it straight up and out of the VM 700T chassis f Remove the cable to the On Off switch from the power supply VM700T Video Measurement Set Service Manual Maintenance Figure 6 24 Removing the power supply retaining screws 2 Replace the power supply by performing step 1 in reverse order supply 5 line voltage switch is set to the correct line voltage If the line voltage switch is not set correctly the VM 700T and the power supply can be severely damaged CAUTION When replacing the power supply make sure the replacement power VM700T Video Measurement Set Service Manual 6 39 Maintenance 6 40 Interconnect Board Assembly A11 The Interconnect board assembly A11 consists of three circuit boards assembled with connectors screws and spacers This assembly is replaced as a unit All VM 700T circuit boards in the two card cages plug into the Interconnect board assembly Removing and replacing this assembly requires removing the boards from the card cages removing wires and attaching screws and lifting the main interconnect assembly from the instrument The following procedure describes removing and replacing the main interconnect assembly 1 Perform the following steps to remove the Interconnect board assembly a Remove the instrument cover panels refer to Cover Panel Removal and Replacement on page 6 8 b Remove the CPU board from the
249. ignal typically comes from a modem and indicates that a phone connection is made 2 RD Receive The VM 700T receives data on this pin Data 3 TD Transmit The VM 700T transmits data on this pin Data 4 DTR Data Required for modem connections only This pin is always high when Terminal the VM 700T is turned on When DTR is asserted the modem knows Ready itis connected to a live P C terminal 5 SG Signal Ground 6 DSR Data Set Unused in the VM 700T Ready 7 RTS Request With hardware flow control CTS RTS selected normally RTS to Send data to connects to the CTS line of a terminal and the line is active when the the VM 7007 VM 700T is ready to receive data When the receive buffers of the VM 700 are nearing capacity RTS goes inactive indicating to the sending device to stop transmitting data With software flow control setto XON XOFF or with None selected RTS is always active 8 CTS Clearto With Flow Control CTS RTS selected the VM 700T is enabled to Send transmit data by a high level on pin 8 and is disabled by a low level It is normally connected to the RTS line of a terminal With Flow Control None or XON XOFF selected the VM 700T transmits data regardless of the CTS level 9 RI Unused in the VM 700T Parallel Port Interface multipurpose I O controller provides the interface between the parallel port and the CPU Only the parallel port controller is used for this applic
250. igure 6 44 Touch screen calibration display TOUCH PANEL INTERFACE CAL PANEL press AUTO to abort TOUCH THE DOT INSIDE THE SQUARE Place finger tip directly over the dot being careful to avoid parallex touching the dot until the square highlights and beeper sounds SQUARE LOCATIONS SEQUENCE Screen SQUARES will appear near the screen corners 1 2 5 will be 3 4 1 2 3 4 as indicated to the right Figure 6 45 Touch screen calibration panel VM700T Video Measurement Set Service Manual 6 69 Troubleshooting Procedures 7 After you have touched the dots at all four corners a screen displaying some typical panel calibration factors is displayed as shown in Figure 6 46 From that screen you can press any key to return to the VM 700T startup menu PANEL CALIBRATION VALUES XSCALE 471 XOFFSET 292 YSCALE 398 YOFFSET 231 Press Any Key to Continue Figure 6 46 Panel calibration values Setting the Power Up You can configure the instrument to always skip the power up diagnostics or to Mode always run them at power up To access the diagnostics menus press and hold in the Menu button while turning on the power to display the VM700T Startup menu shown previously in Figure 6 40 on page 6 66 In the VM700T Startup menu highlight the C in the Diagnostic Configuration line and press the Select Line button This brings u
251. ing Test For Laboratory Benchtop Instruments instrument meets performance specifications at these levels 10 minutes of vibration in each of the 3 major axes including the following levels 0 00015 g2 Hz from 5 to 350 Hz 3 dB octave from 350 to 500 Hz 0 000105 g2 Hz at 500 Hz Overall level of 0 27 GRMS Tektronix Class 5 Shock Test 16 drops 4 axes 30 Grms 11mS half sine wave 1 See the VM700T Environmental Characteristics in Table 1 6 for the operating temperature range of the VM700T operating without the Power Line Conditioner box inline VM700T Video Measurement Set Service Manual Specification PAL Measurement Specifications Measure Mode Table 1 15 Bar Line Time This section lists the specifications for each PAL measurement The accuracies shown for measurements with averaging capabilities assume the default averaging factor of 32 Test signals of known parameters are provided by characterized and traceable television signal generators to test the accuracy of these derived measurements Due to the statistical nature of digitizing measure ment methods reported results will meet these specifications 97 of the time measurement accuracies specified are valid only with nominal inputs signals with an unweighted signal to noise ratio of at least 60 dB on the incoming signal and a termination accuracy of 0 025 Accuracies shown for measurements with relative mode accuracy assume that an averaging fact
252. ing the ADC board A3 consists of removing the instru ment top and right side covers disconnecting three flat cable assemblies disconnecting a shielded cable and removing the screws holding the board in position With the screws removed the board may be lifted from the VM 700T chassis and set aside Required Tools Use the following tools to remove the ADC circuit board W Pozidriv screwdriver 1 X 2X Procedure Use the following procedure to remove and replace the ADC board 1 Perform the following steps to remove the ADC board a Remove the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 Remove the card cage retainer refer to step 1 on page 6 16 Disconnect the flat 10 conductor cable between J111 and J6 on the Genlock board Disconnect the shielded cable between J765 located on the ADC Filter board and J6 on the Analog Input board see Figure 6 17 At the Acquisition Memory board right side of the instrument disconnect the cable at J6 Disconnect the power bus cable at its five connectors and then remove the cable Remove the five board retaining screws and carefully lift the board from the VM 700T chassis 2 Perform the following steps to replace the ADC board a Carefully place the board in the chassis and onto the bulkhead standoffs be sure the cable extends out the side of the chassis Install the five board retaining screws Install the
253. inputs is selected in turn converted and displayed For the 4 inputs that are connected to known values i e 025 4 and U121 6 to 2 5000 VDC and 025 11 and U121 9 to ground the values are read and compared against high and low limits In these 4 cases the tests will fail if the values are out of limit The other 12 inputs are simply read and displayed with the tests always flagged as PASS Cal DAC Wraparound One of the outputs of the calibration DAC U135 21 is connected to one of the inputs of the voltmeter via U121 10 This fact is exploited to perform a wraparound test using three different voltages 0 0 1 25 and 2 5 VDC 6 108 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Table 6 13 SDI Option 1S diagnostic test descriptions Cont Test name Description PLL Centeriing This test verifies the tuning range ofthe VCO phase lock loop at 143 Mb 270 Mb and 360 Mb LTC Chip The LTC chip U60 receives longitudinal time code from an external source The chip is a ICS 2008A Its functions are entirely hardwired and the diagnostic has little to do except resetthe device by toggling pin 2 high then low waiting 33 ms for the device to lock to any external signal that may be present and then reading the status from the chip If the status says that there is no signal bit 2 of register SMPTE1 is 0 then the test is flagged as N A because this condition means thatthe chip thinks there is no valid si
254. io option boards VM700T Video Measurement Set Service Manual 6 95 Troubleshooting Procedures e e F2 e 15Ve GND e i5Ve U32A 10 i GND U53 U31 F1 Figure 6 64 Test positions on the Audio Analog board 6 96 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Audio Option Diagnostics Audio Processor board has no test points or adjustments Troubleshooting this board consists of running its diagnostics If the board passes the diagnostics it is operating correctly if it fails it must be replaced The video measurements of the VM700T are still usable if the VM700T passes the rest of the diagnostics Table 6 11 describes the Audio Processor board diagnostics and Table 6 12 describes the Audio Analog board diagnostics Like the other VM 700T user selectable diagnostics these can be configured to run at power up on demand or in a continuous loop when either Option 40 or Option 41 is installed in the VM700T Video Measurement Set Table 6 11 Audio Processor board diagnostics Test name DSP program RAM Description Standard RAM tests that check decoded address space size RAM segment size and integrity of address and data bus to each block of parts Tests perform a simple checker board pattern test of RAM from the 68020 with the 56001 disabled Data is read as 32 bit
255. ion 40 and Option 41 Option 40 and Option 41 The VM 700T audio measurement options expands the power of the VM 700T Video Measurement Set to include comprehensive audio measurement capabili ties VM700T Option 40 and Option 41 capabilities include m automated and manual audio measurements m audio spectral analysis with harmonic analyzer stereo monitoring B real time display of audio parameters m multitone testing These options also enable the VM 700T to continuously monitor audio test lines for the presence of a test sequence designed for automated testing the TEK sequence The audio option tests to ANSI standard T1 502 1988 EIA TIA 250 C or CCITT Recommendation O 33 The audio results received with automatic monitoring can be included in the VM700T Auto Mode video measurements display with the time and date of the last sequence received Timed reports and the logging of results can be performed automatically Also a file in the VM 700T Measurement Results directory is updated each time an audio auto test sequence is received and measured Option 40 has two stereo input channels connected through mini XLR connec tors Two mini XLR adapters are provided to make signal connections to the inputs Option 41 provides for three stereo input channels connected through a male DB 37 connector A female DB 37 connector is provided with Option 41 to use for fabricating the interconnecting cable that applies the signals to be measu
256. ional blocks of the circuit board SYSTEM BUS DRAM MC68331 MC68030 2M x 32 Data Loop NVRA RS232 Address Loop EPRO 128K x 8 NVRA Shared RAM CELDS 32K x 8 Address 20 u Sec Real Time Buffer Timer Clock Data Buff Reset Clock Flash EPROM Video Display DIP Switch Serial ID Port VGA To Display NOP Output Monitor Figure 3 5 CPU board block diagram A buffer connects all 32 data and address lines and the appropriate control lines from the CPU bus to the system bus VM700T Video Measurement Set Service Manual Theory of Operation EPROM EPROM is a 16 bit wide device with a maximum allowed memory of 512 Kbytes This is a read only memory where the system boot up code resides Under normal operation after the boot sequence is complete the CPU executes instructions contained in Flash ROM programmable read only memory NVRAM 128k x 8 volatile static RAM module with battery backup is used as the nonvolatile random access memory device User programmed routines front panel setups and measurement results are stored in the NVRAM The memory interface allows byte access only The memory defaults to read only at power on or after a system reset NVRAM SIMM NVRAM consists of two banks of 512 kilobytes SIMM of 32 bits width It is a low power static memory The memory interface allows byte word and long word access The memory defaults to read only at power up or after a system reset The memory interf
257. ions pin 1 ground pin 2 hot pin 3 cold See Figure 2 12 on page 2 19 for XLR connector pin locations For level accuracy level flat ness frequency and phase measurement accuracy proce dures In distortion measurement procedure connects two sine wave generators to one Op tion 40 input Supplied with Option 40 Fabricated by user Dual male XLR to single female XLR connector mates with 2 female XLR to male mini XLR adapter cables Dual female XLR to DB 37 female adapter cable XLR connectors must be wired to current AES recommenda tions pin 1 ground pin 2 hot pin 3 cold XLR connectors must be wired to current AES recommenda tions pin 1 ground pin 2 hot pin 3 cold See Figure 2 14 on page 2 20 for pin outs ofthe VM 700T female DB 37 connec tor In frequency and phase mea surement accuracy procedure used to apply signal from one sine wave generator to both Option 40 inputs Used to connectthe sine wave generator to the triple VM 700T audio inputs of Option 41 Fabricated by user Fabricated by user a DB 37 connector is included with Option 41 1 The TEGAM 505010 sine wave generator requires a TEGAM TM500 or TM5000 series power module 4 14 NOTE Before performing the level accuracy procedure Verify the sine wave generator level at 120 Hz by measuring with an accurate AC voltmeter such as a HP 3458 Digital Voltmeter You may also use an AC voltage cali
258. isition is performed The 10 data bits are checked for movement and any bits that are stuck high or low are reported to the console If there is no signal on ChannelA as determined by checking the signal present locked bits this test will be flagged N A VM700T Video Measurement Set Service Manual 6 111 Troubleshooting Procedures Table 6 13 SDI Option 1S diagnostic test descriptions Cont Test name SDI Wander Path Description This test checks the drift rate circuitry The DRIFT SRC bits 2 0 into pins 9 10 11 of U129 are set via control register 1 to route CTRL STEP into pin 13 outto the outputs DRIFT CLK 2 0 is also setto select pin 2 of U130 CHOPPER EN to the output pin 5 Following this 10000 cycles ofthe following sequence are performed SetU129 13 high SetU130 2 high SetU129 13 low Clock U130 2 twice This causes the counters U132 and U133 to cycle through all their states several times and for each of these states to be latched into U24 The output of U24 is routed to the data acquisition After the acquisition has been performed the data is checked to ensure that all 8 bits are moving If so the test passes Otherwise a message is generated to the console for each bit that is stuck low or high Supermux Tests Acquired data consists of a 10 bit data sample and 4 flag bits captured synchronously Each of these flag bits can be fed by a variety of sources such as line and frame sync pulses from
259. istic Description Mains Voltage 90 VAC to 132 VAC 115 VAC nominal 180 to 250 VAC 230 VAC nominal Mains Frequency 50 or 60 Hz Power Consumption 250 Watts 400 VA maximum Fuse Rating Low Input Range High Input Range Cooling Method VM700T Video Measurement Set Service Manual 6A slow blow 3A slow blow Forced air circulation Specification Environmental Table 1 6 Environmental specification Characteristic Temperature Operating Nonoperating Altitude Nonoperating Performance requirement 0 C to 50 C 55 C to 75 C To 50 000 feet 15240 meters Operating To 15 000 feet 4572 meters Sine Vibration Operating 10 Hz 55 Hz 0 015 inch peak to peak 15 minutes total cycling time per axis for three axes followed by a 10 minute dwell at the identified resonance frequency or at 33 Hz if none is found Shock Nonoperating 50 g s 1 2 sine 11 ms duration 3 shocks per surface 18 shocks Transportation Humidity Operating Nonoperating 1 4 Qualified under NTSB Test Procedure 1A Category II 30 inch drop Up to 95 at or below 50 C Up to 95 at or below 60 C VM700T Video Measurement Set Service Manual Specification Table 1 7 Certifications and compliances Category Description EC Declaration of Meets intent of Directive 89 336 E EC for Electromagnetic Compatibility and Low Voltage Directive 73 23 ECC Conformity for Product Safety Comp
260. l number at which the part was discontinued No entries indicates the part is good for all serial numbers 5 This indicates the quantity of parts used 6 Name amp description An item name is separated from the description by a colon Because of space limitations an item name may sometimes appear as incomplete Use the U S Federal Catalog handbook H6 1 for further item name identification 1 Mfr code This indicates the code of the actual manufacturer of the part 8 Mfr part number This indicates the actual manufacturer s or vendor s part number Abbreviations Abbreviations conform to American National Standard ANSI Y 1 1 1972 Mfr Code to Manufacturer The table titled Manufacturers Cross Index shows codes names and addresses Cross Index of manufacturers or vendors of components listed in the parts list 10 2 VM700T Video Measurement Set Service Manual Replaceable Mechanical Parts Manufacturers cross index Mfr code Manufacturer 61153 A amp B PLASTICS INC TK2541 ELECTRONICS LTD 00779 AMP INC 0 7N4 ARCHERS PRECISION SHEET METAL INC 2K262 BOYD CORPORATION 2W733 BELDEN WIRE amp CABLE COMPANY 85480 BRADY USA 32559 BIVAR INC 71400 BUSSMANN 93907 CAMCAR DIV OF TEXTRON INC TK1907 CRESCENT MFG 0 260 COMTEK MANUFACTURING OF OREGON TK1161 DTM PRODUCTS INC 0B445 ELECTRI CORD MFG CO INC 78553 EATON CORPORATION 9M860 ESAM INC 13143 FISCHER SPECIAL MFG CO 06666 GENERA
261. latches and push the instrument fully into the rack 5 Tighten the knurled retaining screw To remove 1 Loosen the retaining screw and pull the instrument outward until the stop latches snap into the holes 2 Press the stop latches and remove the instrument o000 Figure 6 30 Installing and removing the VM700T from the rack 6 48 VM700T Video Measurement Set Service Manual Troubleshooting Procedures The troubleshooting material provided in this section is general and is not intended to cover specific instrument malfunctions This section contains the following subsections m Troubleshooting techniques page 6 50 m Isolating operational faults page 6 51 m Diagnostics page 6 55 Low level diagnostics page 6 59 m Diagnostic utilities page 6 65 m Calibrating the touch screen page 6 68 m Setting the power up mode page 6 70 m VM700T boot switch and diagnostic LED page 6 73 m Running the high level diagnostics page 6 74 m Auto reset running all diagnostics page 6 84 m Viewing stored diagnostic information page 6 84 m Viewing diagnostics remotely page 6 85 m Troubleshooting the power supply and the CRT display page 6 90 m Troubleshooting Option 40 and Option 41 Audio page 6 95 m Troubleshooting Option 48 GPIB page 6 99 m Troubleshooting Option 1S SDI page 6 100 More Information The following useful troubleshooting information can be found
262. ld the it against the board to prevent folding and place the board in the chassis and onto the bulkhead standoffs be sure the cable extends out the side of the chassis b Install the five board retaining screws c Install the cable on its connector at J2 on the Acquisition Memory board d Install the power bus cable on its five connectors VM700T Video Measurement Set Service Manual Maintenance 922 1923 1915 4 2 on the A18 Acquisition board J418 Power bus cable VM700T top view Figure 6 18 Removing the Filter Switch board e Replace the wire connecting A4 J915 to Al J922 f Replace the wire connecting A4 J418 to A1 J923 Install the card cage retainer refer to step 4 on page 6 17 h Install the top and right side cover panels refer to Cover Panel Removal and Replacement on page 6 8 VM700T Video Measurement Set Service Manual 6 31 Maintenance Display and Control This section describes removing and replacing the VM700T components Components Removal and responsible for instrument display and user interface These components include Replacement the CRT assembly the touch panel and the keypad board assembly Removing and replacing these components requires first removing the instrument cover panels the CRT bezel and to remove the keypad board assembly the right side card cage re
263. lesse eee 6 73 Figure 6 51 High level diagnostics 6 74 Figure 6 52 Select run mode the high level diagnostic initial menu 6 75 Figure 6 53 Interactive run mode menu after running first main test 6 77 Figure 6 54 Power up diagnostics selection display 6 78 Figure 6 55 High level diagnostics test blocks 6 79 VM700T Video Measurement Set Service Manual vii Table of Contents List of Tables viii Figure 6 56 Figure 6 57 Figure 6 58 Figure 6 59 Figure 6 60 Figure 6 61 Figure 6 62 Figure 6 63 Figure 6 64 Figure 6 65 Figure 6 66 Figure 6 67 Instrument Run Modes menu Boot switch setting to enable diagnostic output to serial port O Diagnostics Configuration menu VM700T rearpanel cn oo eis ea Ree RE Front panel power supply and over temperature indicators Power supply LED indicators Power supply test e e ER EX ERES Procedure for troubleshooting the audio option boards Test positions the Audio Analog board SDI board cable connections and J5 pinouts Option 1S simplified block Signal connections for performing Option 15 diagnostic tests Figure 9 1 VM700T Video Measurement Set
264. liance was demonstrated to the following specifications as listed in the Official Journal ofthe European Communities EN 55103 Environment Part1 EN 55022 EN 55103 1 Annex A EN 55103 1 Annex B EN 61000 3 2 Part2 IEC 61000 4 2 IEC 61000 4 3 IEC 61000 4 4 IEC 61000 4 5 IEC 61000 4 6 IEC 61000 4 11 EN 55103 2 Annex A EN 55103 2 Annex B Product family standard for audio video audio visual and entertainment lighting control apparatus for professional E2 commercial and light industrial Emissions Class B Radiated and Conducted E missions Radiated magnetic field emissions Inrush Current AC Power Line Harmonic Emissions Immunity Electrostatic Discharge Immunity RF Electromagnetic Field Immunity Electrical Fast Transient Burst Immunity Power Line Surge Immunity Conducted RF Immunity Voltage Dips and Interruptions Immunity Radiated Magnetic Field Immunity Balanced Ports Common Mode Immunity Australia New Zea Complies with EMC provision of Radiocommunications Act per the following standard s land Declaration of uen Conformity EMC AN NZS 2064 1 2 Industrial Scientific and Medical Equipment 1992 FCC Compliance The instrument complies with the radiated and conducted emissions requirements of FCC Code of Federal Regulation 47 Part 15 Subpart B Class A limits 1 To ensure compliance with the above requirements only high quality shielded interface cable should be attached to this in
265. llel Alarm RS 232 output printer port connector ports Figure 6 59 VM700T rear panel The Communications Setup file located in the Configure Files directory contains the parameter settings for the serial ports Typical Communications Setup choices for VM700T to PC communications are shown in Table 6 6 Table 6 6 Typical communication setup parameters Parameter Selection Protocol None Baud Rate to match PC Disabled Flow Control XON XOFF Carrier Detect Disabled Character Size 8 VM700T Video Measurement Set Service Manual 6 87 Troubleshooting Procedures VM700T RS 232 Connector Pin Outs The two RS 232C DTE ports of the VM700T are used to output graphics and reports to a printer as well as for remote operation via a modem or direct serial connection Both connectors are located on the CPU I O board and are accessible on the rear panel Both are 9 pin male D connectors The Communications Setup file is found in the Configure Files directory press Configure and then touch the Configure Files soft key and contains parameter settings for both ports Configuring the Communication Setup file is covered in the VM 700T Option 01 amp Option 11 User Manual Table 6 7 describes the signals the VM 700T outputs and the input signals required on all the active pins of the serial ports Table 6 7 VM700T RS 232 connector pin outs Pin number Function Description 1 DCD Data Carrier Detect This signal typically comes fro
266. ller Synch State Machine PAL VCO Trigger RAM A18c A2a Synch Detect A2b Frame Detect A2c A18b Acquisition Data Path DVM 184 Acquisition Data Path Timing Data Acquisition Data Path Acquisition Timing Data iod Data Path Machine A18 Acquisition Mem Access Accessory Board s Audio GPIB etc Figure 6 55 High level diagnostics test blocks VM700T Video Measurement Set Service Manual A5 CPU Acduisition Acquisition Data Path Data Path 1 Front Panel Display A5a Acquisition Data Path NVRAM 54 ROM Acquisition Data Path Access 1 RAM 5e Access Access hardware A5i Note DVM inputs are not shown 6 79 Troubleshooting Procedures Table 6 4 lists and describes the VM 700T high level diagnostic tests Additional diagnostics are added to this list with the addition of the hardware options GPIB Interface and Audio Measurements Table 6 4 User selectable diagnostics 1 Status Checks Board tested Genlock A2 Description Verifies thatthe Genlock status register correctly represents the hardware configuration These tests must pass to run the lock tests Checks the ability of the Genlock A2 to acquire and hold lock using each VCO The test forcefully breaks lock by toggling rapidly between inte
267. located in the left side card cage The analog section boards Analog Input A1 Genlock A2 ADC A3 and Filter Switch A4 are mounted with screws and standoffs on a bulkhead under the top cover panel see Figure 6 1 VM700T Video Measurement Set Service Manual Maintenance Front of the instrument Figure 6 1 Locating the major standard assemblies 6 7 VM700T Video Measurement Set Service Manual Maintenance Cover Panel Removal and Replacement 6 8 Most of the VM 700T circuit boards may be accessed by first removing three sheet metal panels that cover the top and two sides of the instrument Removing the keypad board assembly and other display and control components from the front of the instrument also requires removing the bottom cover panel The four cover panels are positioned with slotted corner extrusions and fastened with screws to the instrument rear panel Removing each cover panel requires removing its fastening screws on the rear panel and sliding the panel toward the rear of the instrument and out of the grooves in the chassis frame Replacing each cover panel is the reverse of the removal procedure Required Tools Use the following tool to remove the cover panels W Pozidriv screwdriver 1X Procedure Use the following procedure to remove and replace the cover panels 1 Remove the screws at the rear edge of the cover panel to be
268. lock that failed the subtest titles are shown in the test block with any that failed marked with FAIL Passed subtests are marked with Pass There two additional soft keys labeled Continue and Rerun Test displayed on the screen Continue resumes the diagnostic Rerun Test repeats execution of the test family Certain of the diagnostics will also display the message Automatically Continues in 60 Seconds after a failure and count down as the time elapses NOTE The powerup function key will not run at power on when GPIB is selected as the remote control port When all the tests within a diagnostic routine have been completed the Select Run Mode screen is displayed From the VM700T Diagnostics Startup menu select R INSTRUMENT RUN MODES This brings up a second menu the INSTRUMENT RUN MODES MENU see Figure 6 49 In that menu select A AUTO RESET That causes all the diagnostic test to run one time before doing the system initialization Interactive Mode Interactive Mode provides a greater level of detail for most tests within a diagnostic routine than Power Up Mode Interactive Mode when selected displays the Change Run Mode soft key Touching the Change Run Mode soft key returns you to the SELECT RUN MODE screen In interactive mode each main test block runs and the test halts at the end of each block The main test title and all the subtest titles are shown with a Pass or FAIL label You are given the choic
269. log input board A1 through one of three high impedance loop through connectors see the overall block diagram in the diagrams sections of this manual After it buffers and clamps the input signal and selects a channel the A1 board passes the signal to the A4 filter switch board where analog filtering signal conditioning occurs After filtering the filter switch board returns the video signal to the A1 board for analog processing offset gain and dither are dynamically applied The signal then passes to the analog to digital ADC converter board A3 where it is digitized The A2 genlock board uses an external sync or the sync from one of the three video input channels to create a sampling pulse synchronized genlocked to the incoming sync pulses A 10 bit analog to digital flash converter digitizes the video signal After digital conversion the differential ECL data is clocked to the acquisition controller board A18 The data acquisition controller board A18 converts the ECL data to single ended TTL data and stores it in the acquisition memory The data acquisition memory consists of static RAM accessible by the CPU during data acquisition the memory appears to be dual ported Besides converting ECL data to single ended TTL the controller portion of the board controls data acquisition patterns that handle the following analog processing hardware functions clamping input selection sync source filter selection offset gain di
270. luding at least a 10 W 2A load on the 5 1 V supply VM700T Video Measurement Set Service Manual Troubleshooting Procedures Power Supply Voltage and Ripple Check To check the power supply for voltage and ripple tolerances the bottom cover of the VM 700T must be removed Turn off the VM700T and remove the bottom cover Use Figure 6 62 to locate the power supply voltage test points this information is also on the bottom cover of the power supply Refer to Table 6 10 for the tolerance and ripple values 15V GND GND 42V Fan GND A 12V to 428 V FAN A A J3 HV Ground 5 2 V 15 V Figure 6 62 Power supply test points Table 6 10 Power supply voltages Voltage Tolerance standard P A R D max mV Circuitry supplied load ripple 5 Vdc 1 18A 150 TTL Logic 15 Vdc 120 Analog 15 Vdc 120 Analog 12 Vdc 150 Display 12 to 30 Vdc Drive 52 Vdc 150 ECL Logic VH Control Circuitry Total Periodic and Random Deviations Pard measured at the power supply output connector includes peak to peak noise ripple switching spikes etc within a bandwidth from 5 Hz to 20 MHz Thehousekeeping voltage VH is 11 4 V before the rest of the power supply comes on line VM700T Video Measurement Set Service Manual 6 93 Troubleshooting Procedures Trouble
271. ly If you do not have the required test equipment we recommend that you have the adjustment procedure done at the factory Contact your nearest Tektronix representative for information Table 5 1 Test equipment required for verification and adjustment Equipment Minimum specification Purpose Example Video amplitude calibrator Square wave 0 0 mV to Reference standard for Tektronix 067 0916 00 not 999 9 mV peak accuracy amplitude verification currently available for 2 105 resolution mv purchase Leveled sine wave generator 75 Q output impedance Measure sine wave filter Hewlett P ackard 3336C output flat within 0 025 dB flatness adjustment Sine wave generator with 20 396 to 6 MHz option 0052 Television signal generator NTSC full field and burst NTSC test signal source Tektronix TSG 170A or equiv Capability accurate to 1 Hz alent Television signal generator PAL full field and burst PAL test signal source Tektronix TSG 271 or equiva Capability accurate to 1 Hz lent Frequency counter External reference capability Adjustthe GenLock VCO Tektronix DC 503A TEGAM or ratio A B 8 digit display DC 503A or equivalent Digital multimeter DC Volts range 20 mV to Adjust the GenLock VCO Tektronix DM 502A or equiv alent 200 V 3 1 2 digit display adjust CalDac VM700T Video Measurement Set Service Manual 5 1 Adjustment Procedure Table 5 1 Test equipment required for verification and adjustment cont
272. ly for example to get a better reading on a calibration result that is within limits can introduce errors into a functional instrument 17 If adjustment is needed slide the top cover back enough to expose the Genlock board and quickly adjust R138 TCXO REFERENCE on the Genlock board to set the Burst Frequency measurement to zero Slide the top cover back on the VM700T After 5 minutes check the Burst Frequency measurement again to verify that it remains within tolerance NOTE If you performed this procedure after getting out of limit results from Measuring the Burst Frequency in the Performance Verification procedure return to finish the verification steps now This procedure is used to adjust the frequency response flatness over the operating range of the VM700T after a board exchange repair or after it is determined that the flatness is out of tolerance by doing the Measure Sinewave check procedure Test Equipment Required Leveled sine wave generator 75 output impedance output flat within 0 025 dB 0 3 to 6 MHz Example HP 3336C with option 005 m Termination 75 precision Tektronix part number 011 0102 01 or equivalent Coaxial cable 75 Q high quality noise free 1 meter length Tektronix part number 012 0074 00 Adjusting Filter Flatness 1 Setthe leveled sine wave generator for 50 kHz at 500 mV into 75 NOTE If the example leveled sine wave generator is being used the output level
273. m Channel phase difference 1 for inputs of 40 Hz to 20 KHz 2 for inputs of 20 Hz to 40 Hz at a level of 40 dBu or greater Option 40 Frequency 1 Connectthe sine wave generator output to both the left and right inputs of Accuracy and Channel the Audio board see Figure 4 6 2 Setthe sine wave generator for a frequency and amplitude in the specified frequency and amplitude range of the Audio option 20 Hz to 20 KHz amplitude of 60 dBu or greater NOTE Use a test signal level of at least 60 dBu test at least 10 frequencies over the entire range Tested frequencies should include the specification limits 20 Hz 20 kHz and the 40 Hz breakpoint Example frequencies to test might also include the following 100 Hz 200 Hz 1 kHz 2 kHz 10 kHz 3 Check that the measured frequency is accurate to the limits shown in Table 4 3 for the applied test signal frequency and level Check that the phase difference between channels meets the phase difference specification 4 18 VM700T Video Measurement Set Service Manual Audio Option 41 Triple Input Verification Procedure This section describes the differences in operation between Option 40 and Option 41 and it gives the verification procedure for Option 41 Configuring Source Selection Audio The Option 41 software is similar to the Option 40 software except for the Source Selection Audio file The Source Selection Audio file lets you specify an Op
274. m a modem and indicates that a phone connection is made 2 RD Receive Data The VM 700 receives data on this pin 3 TD Transmit Data The VM 700T transmits data on this pin 4 DTR Data Terminal Ready This pin is always high when the VM 700T is turned on Modems typically require this signal to be a high level or they won t answer the phone 5 SG Signal Ground 6 DSR Unused in the VM 700T and not internally connected 7 RTS Request Send data With hardware flow control CTS RTS selected to the VM 700T normally RTS connects to the CTS line of a terminal and the line is active when the VM 700T is ready to receive data When the receive buffers of the VM 700T are nearing capacity RTS goes inactive indicating to the sending device to stop transmitting data With software flow control XON XOFF selected or None selected RTS is always active 8 CTS Clear To Send With Flow Control CTS RTS selected the VM 700T is enabled to transmit data by a high level on pin 8 and is disabled by a low level It is normally connected to the RTS line of a terminal With Flow Control None or XON XOFF selected the VM 700T transmits data regardless of the CTS level 9 RI Unused 6 88 VM700T Video Measurement Set Service Manual Troubleshooting Procedures NOTE Not all RS 232C devices use control lines as described in this section Refer to the instruction manual of the equipment you are connecting
275. mation Setting the Power You can configure the measurement set to always skip the power on diagnostics Mode orto always run them at power on Use the following procedure to access the diagnostics menus 1 Press and hold in the Menu button while turning on the power to display the VM700T Startup menu shown in Figure 2 2 on page 2 5 the startup menu highlight the C in the Diagnostic Configuration line and press the Select Line button 2 This brings up the Diagnostics Configuration menu shown in Figure 2 6 In this menu highlight and select P in the Set Diagnostics Powerup Mode line to bring up the powerup mode choices shown in Figure 2 7 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection DIAGNOSTICS CONFIGURATION MENU Key Selection P Set Diagnostics POWERUP MODE I Set Diagnostics INTENSITIES Set Low Level Diagnostics Console DEFAULT BAUD RATE Reprint 8 Abort Menu Input your selection Figure 2 6 Diagnostic configuration menu 3 In the Set Diagnostics Powerup Mode menu either highlight and select to have the measurement set skip diagnostics on power up or highlight and select P to have the measurement set run diagnostics on power up When you make the selection it is stored in the diagnostics NVRAM The other choices in the menu are used in diagnostic testing in manufacturing and factory service 4 Atthis point the quickes
276. may occur The over temperature warning occurs at about 50 C and the power supply will shut down at about 60 C The ambient temperature may be too high to operate the VM700T or the flow of cooling air is cut off or restricted The VM700T should be shut off to let it cool down before a shutdown occurs VM700T Video Measurement Set Service Manual Troubleshooting Procedures Internal Checks If the PS Fail indicator is on then there is a power supply problem Turn off the master ON OFF switch on the rear panel of the VM 700T and remove the holding screws from the right side as viewed from the front cover Slide the cover back about 8 inches to gain visual access to the power supply LED indicators Locate the power supply LED indicators near the front at the bottom of the chassis see Figure 6 61 Turn the master ON OFF switch back ON Front OT OVERTEMPERATURE Dos Ol OVERCURRENT OV OVERVOLTS UV UNDERVOLTS ss Red LED indicators Green LED indicators all off when normal all on when normal 00000 UV OV OI OT 5 52 5 2 15 VH Figure 6 61 supply indicators Check that the VH housekeeping supply LED indicator comes on see Figure 6 61 If it does not come on replace the power supply Refer to Power Supply Module on page 6 38 for power supply removal instructions Check the green LED indicators on the power supply Each voltage supply is provid
277. mbly 10 Refer to Removing and Replacing the Keypad Board assembly Replace the display memory SIMM on the CPU board Replace the CPU board This action requires a complete reprogramming for the replacement CPU board Check GPIB cable connection Replace the GPIB cable Check for correct controller operation Replace the GPIB interface board Check for correct cable and port connection Incorrect communication parameters Faulty 1 0 board Check for correct parameters in Communication Configuration file Replace the 1 0 board 6 54 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Diagnostics Diagnostics in the 700 Video Measurement Set are divided into two sets low level and high level The distinction between the two types is based upon the operating system those diagnostics that run before the instrument s operating system is booted are referred to as low level those that run as applications executed by the operating system are referred to as high level The instrument pauses noticeably when the operating system is booting so messages are displayed indicating when this boot is occurring to aid the user in differentiating between high level and low level diagnostics Grouping of diagnostics within the two sets is by circuit board Within a circuit board diagnostic are one or more tests associated with each test is a main pass fail result and where applicable o
278. me decoder or the synthesized frame pulse and converts it into a pulse one sample clock period in duration Control An 8 bit read write register is used for mode control Control bits select the video standard sampling mode frame mode and sound in sync SIS mode Logic provides enables for various hardware functions with LEDs on the circuit board to indicate which of them are in use Status An 8 bit read only register is used to read genlock status Some of the bits indicate the current lock status and history The remaining bits indicate VCO on off status and the genlock hardware revision level LEDs on the circuit board indicate the current lock status and whether any unlocks have occurred since the last read of the status register 3 10 VM700T Video Measurement Set Service Manual Theory of Operation The Analog to Digital ADC Board A3 2 5 V and 2 5V 42 5 V and 2 5 V regulators provide a balanced low noise power source for Regulators the A D converter The 42 5 V source is the output of a 5 V 3 terminal regulator stacked on the 2 5 V supply The 2 5 V supply has a feedback circuit from the A D converter VREF output The feedback circuit adjust the 2 5 V output over 0 5 V range to hold the VREF output at ground reference Signal Conditioning signal conditioning amplifier is a buffer between the anti aliasing filter and Amplifier A D Converter The operational amplifier has 75 input impedance
279. mperature shutdown has occurred The green LED indicators for the supply will be on if a shutdown has not yet occurred Check thatthe fan is operating Over temperature shutdown ofthe supply will occur at about 10 over the warning temperature At that point all the green power supply indicators exceptthe VH LED will be off Over Current LED on Check for flashing supply LED indicators 6 92 Turn off the master ON OFF switch and letthe VM 700T cool down before restarting the power When the power comes back on check that the fan operates and that the power supply operates correctly Check the air filters in the instrument s front bezel If they become clogged the lack of air flow may cause overheating Use a mini vacuum cleaner to remove the dust from the filters For more information on cleaning the front bezel air filters see Cleaning the Touch Screen and Front Bezel Air Filters Check for possible excessive loading on a power supply by the VM 700T Troubleshoot the VM 700T for excessive loading problems Circuit boards may be unplugged one ata time to check for board related loading If the over current fault goes away after you remove a circuit board or disconnect a cable assembly from the instrument that circuit board may be the faulty module Replace with a known good module to check Return a faulty module for replacement or repair Minimum load to maintain operation of the power supply is 30 W total inc
280. n The instrument must have had a warm up period of at least 20 minutes The instrument must have had its signal path compensation routine last executed after at least a 20 minute warm up period at an ambient temperature within 5 C of the current ambient temperature Any conditions that are unique to a particular characteristic are expressly stated as part of that characteristic Electrical Characteristics Table 1 1 Input characteristics Characteristic Channel A B and C Input Type Return Loss 75 Performance requirement Loop through BNC connectors Greater than 46 dB from 0 to 5 MHz Supplemental information User selectable Differential A B A C B A B C C A andC B may also be digitized for parallel component testing Channels A B and C are loop through terminated in 75 in use or not power on or off Input Signal Range Coupling Clamp 13 6 dB with respect to 1 Vp p nominal video 1 41 Vp p to 0 5 Vp p terminated in 150 DC AC Clamp Independently programmable on each channel as follows 1 Timing with respectto sync 2 Clamp pulse width 3 Clamp reference level 4 Clamp time constant VM700T Video Measurement Set Service Manual Specification Table 1 1 Input characteristics cont Characteristic Hum Rejection Fast Performance requirement Greater than 24 dB Supplemental information Slow External Sync Crosstalk Between Channels Less tha
281. n 1 dB Provided through a rear panel input Greater than 70 dB isolation between channels Measured at Fsc between A B C and EXT SYNC Residual Noise Level 0to 5 MHz Better than 80 dB with respect to 0 714 V p p active video Table 1 2 Digitizer Characteristic Distortions 2nd Harmonic Noise Performance requirement Supplemental information 70 dB or less with 2 5 MHz 1 dBfs signal 60 dBfsg us typical with 5 MHz 50 dBfs input Anti aliasing filter attenuation At 7 16 MHz NTSC At 8 86 MHz PAL Table 1 3 Synchronization Characteristic 35 dB or greater 40 dB or greater Performance requirement Supplemental information Modes Video input or external Sound in syncs and PCM2 capable without jumper options Amplitudes Internal Minimum 14 dB with respectto 286 mV nominal sync amplitude Maximum 12 dB with respect to 286 mV nominal sync amplitude External Minimum 8 dB with respect to 286 mV nominal sync Composite sync amplitude Maximum 8 V peak to peak Composite sync 1 2 VM700T Video Measurement Set Service Manual Specification Physical Characteristics Power Requirements Table 1 4 Physical characteristics Characteristic Dimensions W x H x D Weight Shipping Weight Table 1 5 Power requirements Description 19 0 in x 8 75 in x 21 9 in 483 mm x 222 mm x 556 mm 45 Ib 20 kg Approximately 71 Ib 33 kg Character
282. n one quiet line per CCIR Rec 569 61 dB to 70 dB 52 0 dB Luminance Weighted SNR 569 26 dB to 60 dB 11 0 dB Measured on one quiet line per CCIR Rec 569 61 dB to 70 dB 52 0 dB Table 1 46 Incidental Carrier Phase Modulation Measurement Accuracy ICPM requires Zero Carrier P ulse and the quadrature output of the 11 0 demodulator on Channel C 1 18 VM700T Video Measurement Set Service Manual Specification NTSC Measurement Specifications This section lists the specifications for each NTSC measurement The accuracies shown for measurements with averaging capabilities assume the default averaging factor of 32 Test signals of known parameters are provided by characterized and traceable television signal generators to test the accuracy of these derived measurements Due to the statistical nature of digitizing measure ment methods reported results will meet these specifications 97 of the time Range specifies the extremes between which a measurement can be made measurement accuracies specified are valid only with nominal inputs signals with an unweighted signal to noise ratio of at least 60 dB on the incoming signal and a termination accuracy of 0 025 Accuracies shown for measurements with relative mode accuracy assume that an averaging factor of 256 was used to create the reference An IRE is a voltage unit of measure and is equal to 1 140 of a volt or 7 14285 mv 100 IRE is 714 285 mV This value often rounded
283. n page 6 66 2 Use the front panel knob to select in the menu and then press the Select Line button This displays the Instrument Run Modes menu shown in Figure 6 56 3 Use the front panel knob to select A in the Instrument Run Modes menu This restarts the VM700T and runs the full set of internal diagnostics 4 Check that all tests pass as they run If a test fails refer to High Level Diagnostics Test on page 6 78 If the VM 700T diagnostics detect a problem the Console and the Diagnostic Errors files may contain information useful for troubleshooting a problem Both files can be printed using the Print File soft key Console File Whenever the VM 700T initializes information is stored in the console file located in the directory the topmost If a malfunction causes the VM700T to auto reset the console file could contain useful information The console file is rewritten each time the VM 700T is powered on Compare the failure symptoms with the information in Table 6 3 on page 6 52 and run the self test diagnostics to isolate a problem High Level Diagnostic Errors File When user selectable diagnostics are run at power up or during DiagsLoop refer to Diagsloop on page 6 77 all errors detected are written to the Diagnostic Errors file found in directory nvramO ConfigFiles The Diagnostic Errors file is automatically created when an error is detected by user selectable diagnostics NOTE The maximum capacit
284. nal is not present remove the SDI Rear Panel Interface assembly Disconnect the flat cable from the SDI Rear Panel Interface assembly and then check each of the 10 wires in the cable for continuity If the cable is good replace the SDI Rear Panel Interface assembly No Signal From the Perform the following steps when the AES EBU Digital Audio input does not AES EBU Digital Audio operate Input 2 3 1 Connect an AES EBU digital audio signal to Option 1S Check for an audio signal on J5 pin 2 of the SDI board see Figure 6 65 If the audio signal is present on J5 pin 2 replace the SDI board If the audio signal is not present remove the SDI Rear Panel Interface assembly Disconnect the flat cable from the SDI Rear Panel Interface assembly and then check each of the 10 wires in the cable for continuity If the cable is good replace the SDI Rear Panel Interface assembly No Signal From the Perform the following steps when the LTC Time Code input does not operate LTC Time Code Input 2 1 Connect a time code signal to Option 1S Check for a time code signal on J5 pins 4 and 5 of the SDI board see Figure 6 65 If the time code signal is present on J5 pins 4 and 5 replace the SDI board If the time code signal is not present remove the SDI Rear Panel Interface assembly Disconnect the flat cable from the SDI Rear Panel Interface assembly and then check each of the 10 wires in the cable for contin
285. nc to S tart of Burst 2 2 us to 8 us 20 ns 5 6 us nominal Burst Duration 14 us to 3 us 25 ns SCH Phase 90 58 Table 1 39 Field Blanking timing measurements Measurement Range Equalizing Pulse Duration 1 4 us to 20 hs 2 35 hs nominal Broad Pulse Separation 1 4 us to 20 hs 4 7 hs nominal Accuracy 10 ns 10 ns VM700T Video Measurement Set Service Manual 1 15 Specification Table 1 40 Other Timing measurements Measurement Bar Rise Time Accuracy ITS Element Standard 120 ns to 300 ns 20 ns B2 Measured from 1096 to 0 3 us to 1 0 us 30 ns 90 points Table 1 41 Amplitude and Phase measurements Measurement Average Picture Level Sync Amplitude Error Sync Amplitude Error with Sound in S Burst Amplitude Error Chrominance Reference Amplitude Error Accuracy ITS Element Standard 010 200 Pp 100 to 50 0 3 Live picture area CCIR Rec 569 300 mV nominal of nominal 100 to 50 0 3 Last broad pulse in field CCIR Rec 569 300 mV nominal of nominal 480 to 50 11 096 Live picture area CCIR Rec 569 300 mV nominal 8096 to 45096 1 0 D2 CCIR Rec 569 300 mV nominal B2 Luminance Bar 30 to 70 0 3 CCIR Rec 569 Amplitude Error 700 mV nominal Luminance Bar 200 mV to 900 mV 2 2 mV B2 Amplitude Luminance Bar 0 to 90 of 0 3 2 Zero Carrier Amplitude 96 of carrier Maximum Carrier Residual Carrier 0 t
286. nd uses an algorithm that can detect rudimentary vertical sync information produced by VCRs Frame Rate Synthesizer frame rate synthesizer generates a frame rate frequency output that is used in the synthesized frame mode The frame rate synthesizer does not operate in 20 25 MHz sampling mode Stripped Sync Processing stripped sync logic not shown in the block diagram removes noise from the sync stripper s composite sync output In sound in sync SIS mode the SIS pulses are removed by combining composite sync with the sync stripper s horizontal sync output Impulse noise such as VCR head switches is removed by gating composite sync with a 2 microsecond window pulse centered on the leading edge of sync VM700T Video Measurement Set Service Manual 3 9 Theory of Operation Output Generator The output generator provides sampling line and frame strobes to the analog to digital converter ADC board Sampling strobe output A multiplexer selects either the four times subcarrier 4Fsc clock from the phase locked loop or the 20 25 MHz crystal clock A transparent latch stops the clock output when changing sources ensuring a smooth transition between them Line strobe output multiplexer selects either composite sync or the window pulse from the phase locked loop and converts it into a pulse one sample clock period in duration Frame strobe output A multiplexer selects either the decoded frame pulse from the fra
287. ne or more sub results The purpose of this format is to present all the information used within a test to determine its ultimate pass fail status There is another diagnostic tests grouping the Overall Run mode The three choices are Power Up mode Auto Reset mode and User Interactive mode These are discussed later in this section in Selecting an Overall Run Mode on page 6 61 Diagnostics are normally bypassed for a quicker startup but they can be configured to run automatically during a normal instrument powerup The normal powerup mode skips all diagnostics Power up modes can be selected using hardware boot switch settings on the CPU board discussed later in this section or in some cases by pressing and holding certain front panel buttons during powerup referred to as backdoor boot modes For example holding the Menu button in while turning on the power causes the VM 700T to enter the low level diagnostic interface Interactive diagnostics provide the service person choices to control the tests that run and the manner in which they run In the user interactive mode any or all tests within a group of tests can be selected for execution Diagnostics displays can be routed to one of the instrument serial ports for viewing on a terminal This is useful if a malfunction does not permit the testing progress and results to be displayed on the VM 700T CRT A special setting of the boot switch is used to route the diagnostic test displays
288. nents m Flat blade screwdriver 3 16 or inch blade W Pozidriv screwdriver 2X m Combination or open end wrench 5 inch Small wire cutters Power Supply Module The power supply module is located on the right side of the VM700T below the right side card cage You may remove the power supply by first removing the cover panels of the VM700T refer to Removing and Replacing a Cover Panel on page 6 8 for more information and turning the instrument upside down The following procedure describes removing and replacing the power supply NOTE The power supply module is field removeable for replacement only it is not a field serviceable unit 1 Perform the following steps to remove the power supply a Remove the instrument cover panels refer to Cover Panel Removal and Replacement on page 6 8 b Position the VM 700T with its bottom facing up and remove the wires and connectors from the power supply Disconnect the wires to the On Off switch from the switch NOTE The connections are labeled on the power supply You should also tag each wire with a label as you remove it for easy replacement later c From bottom of the instrument remove four attaching screws one screw must be accessed through a slot in the power supply housing See Figure 6 24 d Atthe rear panel remove five retaining screws e Move the power supply to clear the corner rail overhang and holding the wires aside carefully l
289. nerator s four control states are the following W clear sequence to the next dither level VM700T Video Measurement Set Service Manual 3 25 Theory of Operation 3 26 W hold the current level load a custom six bit dither value Figure 3 9 shows the pre defined dither waveform sequence built into the dither generator Figure 3 9 Dither generator 64 step dither waveform When the dynamic settings address buffer is enabled the CPU microprocessor can read or write the dynamic settings static RAM from the dynamic settings data buffer This can occur while the sequencer is running Addresses for the CPU accesses are buffered The CPU microprocessor can be given access to the dynamic settings static RAM or the static RAM addresses may be connected to the 11 bit output from the sequencer address latch The 11 bit output from the sequencer allows for different dynamic output settings for each step of the sequencer program The 32 bits of output latches are divided as follows W eight offset bits eight gain bits W eight bits to drive a dither generator three bits of input selection control m the CPHASE bit inverts the clock phase on the genlock board to allow sampling midway between previous samples four bits control filter selection on the A4 filter switch board Microprocessor access is also a multiplexed operation A DSACK generator provides the rapid signal generation needed for a minimal number of CPU wai
290. ngth cable Leave the SDI Ch A input terminated Table 5 7 Cable meter adjustment value limits 10 MHz demod Short 2 200 to 2 700 2 100 to 2 600 2 100 to 2 600 Long 2 100 to 2 600 2 100 to 2 600 2 000 to 2 500 77 MHz demod Short 2 000 to 2 500 2 000 to 2 500 2 000 to 2 500 Long 1 800 to 2 200 1 800 to 2 200 1 800 to 2 200 5 26 VM700T Video Measurement Set Service Manual Adjustment Procedure 4 Perform the following steps to adjust the Eye Diagram horizontal position and delay a Slide the VM700T right side cover back to access the CPU board dip switch b Setswitch 4 of the dip switch to the open position and then close the side cover See Figure 5 12 c Setthe digital television signal generator to output a 525 line 143 Mb NTC7 combination signal Le Acquisition board ppm SDI board CPU board Setswitch S4 to open SDI board Figure 5 12 Location of CPU board dip switch and SDI board test point and adjustment resistor VM700T Video Measurement Set Service Manual 5 27 Adjustment Procedure 5 28 Press the VM700T front panel Configure button Touch the Configure Files soft key and then touch the Source Selec tion Digital soft key Highlight the Digital A line using the front panel knob and then touch the highlighted line to cause a box to appear around the current selection Turn the knob to select Auto Detect touch the Accep
291. niature XLR Longitudinal Time Code per IEC pub 461 160 kHz and above Max jitter ns 130 jitter frequency KHz for frequencies below 160 kHz Equivalent to 250 meters of Belden 8281 cable typical Supplemental information gt 10kQ VM700T Video Measurement Set Service Manual 1 41 Specification Table 1 107 SDI Output Characteristic Performance requirement Supplemental information Electrical Characteristics Output type BNC 75 compensated Return Loss PowerOn gt 25 dB 1 MHz to 360 MHz Channel on or off Power Off gt 15 dB 1 MHz to 360 MHz Signal Characteristics Amplitude 800 mVp p 10 20 to 80 Rise Fall Time 400 ps to 800 ps Table 1 108 Analog Ref Input Characteristic Performance requirement Supplemental information Electrical Characteristics Input type BNC passive loopthrough 75 compensated Return Loss gt 30 dB 50 kHz to 6 MHz Power on or off Signal Characteristics Amplitude Range 6 dB with respect to 1 Vp p video Table 1 109 AES Audio Input Characteristic Performance requirement Supplemental information Electrical Characteristics Input type BNC 75 Q Return Loss gt 15 dB 0 1 MHz to 6 MHz Signal Characteristics Amplitude Range 0 2 Vp p to 2 Vp p Format AES EBU digital audio per AES 3 1992 ANSI 4 40 1992 Table 1 110 Environmental specification Performance requirement Characteristic Supplemental information VM700T with Op
292. nly with the VM700T when operating the VM700T from a 230 Vac mains source The Power Line Conditioner provides no benefit when the VM700T is operated from a 120 Vac mains source and should NOT be used NOTE The VM700T will not be damaged if operated from a 230 Vac mains source without the Power Line Conditioner connected to the power input VM700T Video Measurement Set Service Manual Operating Information Installing the Power Line Power Line Conditioner be used with either with a rackmounted Conditioner 7 or a standalone VM700T on a benchtop Rackmounted VM700T Use the mounting bracket and screws provided with the accessory to attach the box to a rackmount rail Use only 10 screws for the screw holes in the box Place the box in any convenient location within the rack where you can make the power cord connections see Figure 2 1 NOTE Do not mount the power line conditioning box in any location that blocks the air flow in or out of the VM700T or any other product installed in the rack VM700T 66606060090 VM700T Power line conditioner Install at a convenient location within the rack 230VAC mains power strip O OOo 0 0 0 0 0 Figure 2 1 Power line conditioner with a rackmounted VM700T VM700T Video Measurement Set Service Manual 2 3 Operating Information Power On Diagnostics Calibra
293. nostics refer to Selecting High Level Diagnostics for that procedure m Select Measure mode by pressing the Measure hard key VM700T Video Measurement Set Service Manual Performance Verification m If the Diagnostic measurements are not shown touch the Diags soft key to switch to them m Touch the DiagsLoop soft key to loop the selected continuously Use the Abort Looping soft key to halt diagnostic looping at the end of the warm up period Return to Configure menu check Diagnostic Errors file for new errors Refer to the Diagnostics information in the Maintenance section of this manual for more information on the diagnostics tests and their operation Audio Limit Audio Source Audio Source Files Files Identification Auto Limit Camera Communi cation Files Testing Setup Diagnostics Diagnostic Component Selection Errors Echo Rounding Keasure Limit Meas urenent Files Locations NTSC Files In nvram ConfigFiles Switch Print Leave NTSC PAL File Directory Figure 4 3 Configure directory Selecting High Level Diagnostics diagnostic routines on the Selected side execute during Powerup Diagnos tics if not set to Quick Start and when DiagsLoop is selected To select or unselect a diagnostic from the Di
294. nu Button The Menu button displays a menu of soft keys across the bottom of the touch screen In some cases touching a soft key displays a further submenu of soft keys VM700T Video Measurement Set Service Manual 2 13 Operating Information Control Knob Help Button Pressing the Help button activates the Help function While Help is activated pressing a button or selecting a soft key displays a brief explanation of that button or soft key s function When the Help function is active all buttons and soft keys except Help lose their normal function and the LED on the Help button flashes Pressing the Help button a second time turns off the Help function Configure Button Configure accesses the Configuration files used to control the operation of the measurement set You can also create edit rename print and delete functions with selections available in the Configu ration menu For a full description of the Configure button and the menus accessed refer to the VM 700T Option 01 NTSC and Option 11 PAL User Manual Function Button The Function button accesses user created functions and the selection choices for running them For a full description of creating and editing functions refer to the VM 700T RS 232 Interface Programmer Manual Copy Button The Copy button sends a copy of the display in user select able 24 pin Epson or PostScript format to the measurement set print spooler to queue for printing The LED in the
295. o 9096 of 10 396 B2 and Zero Carrier Bar Top Maximum Carrier Blanking Level 0 to 9096 of 0 2 Live picture area CCIR Rep 624 1 Zero Carrier Chrominance 75 of bar 11 090 G1or G2 CCIR Rec 569 Luminance Gain amplitude Inequality Chrominance Luminance Delay Inequality Sync Bar Rel 3 7 Sync to Bar Top C L Gn Err using modulated Pulse Sync Amplitude Burst Amplitude Burst Amplitude Difference 1 16 300 ns 5 ns F orGlorG2 CCIR Rec 569 0 ns nominal 20 to 110 CCIR Rec 569 0 5Vto2V CCIR Rec 569 75 mV to 600 mV 3 mV 568 VM700T Video Measurement Set Service Manual Specification Table 1 41 Amplitude and Phase measurements cont Standard ITS Element Measurement Accuracy Burst Quadrature Error Differential Gain 0 to 100 0 3 2 CCIR Rec 569 Peak and p p 0 nominal Differential Phase 0 to 360 30 3 D2 CCIR Rec 569 Peak and p p 0 nominal Table 1 42 Frequency Response measurements Measurement Range Accuracy ITS Element Standard MultiBurst Flag 20 to 13096 of bar CCIR Rec 567 Amplitude 6096 nominal MultiBurst Amplitude 0 to 200 of flag 1 5 of flag CCIR Rec 567 100 nominal 2 5 of 5 8 MHz packet Table 1 43 Waveform Distortion measurements Measurement Accuracy ITS Element Standard Baseline Distortion 50 of bar CCIR Rec 569 2T Pulse Bar 42596 to 9096 Bl CCIR Rec 569 Ratio Error
296. o Measurement Set Service Manual 19 F100 A20 F1 1 10 12 11 2 18 Or front of board A17 aa P695 VM700T Video Measurement Set Service Manual 1 5 Fuse located on the back of board tab A18 A5 048 U50 LEN U46 Figure 10 6 Circuit board fuse locations 10 27 10 28 VM700T Video Measurement Set Service Manual
297. o Signal Interconnection Cable 2 20 GPIB Option 48 Signal Connections and Rear Panel 2 21 GPIB Indicator 2 21 SDI Option 1S Rear Panel Connections 2 22 Theory of Operation Overview or The 700 System essa sessi a yokes eee whe 3 1 Module Functional Description 3 3 Analog Input Board AD 564 84 rer 844545 SERS Rows OHO 3 3 The Genlock Board A2 ERI EE LR RR DES 3 7 The Analog to Digital ADC Board 3 11 Filter Switch Board 4 3 14 CPU Board A5 2 CR CUP Rae eee ORES DU 3 16 CPU I O Boatd A20 ULT PPP S 3 18 Data Acquisition Controller Board A18 3 20 Front Panel Board 10 1 3 27 Keypad Board 2 55 24 cem scere pe RES XS RAW PSI ENS 3 28 Main Interconnect Board Left and Right 3 29 Picture Monitor ATA EE ES 3 29 Power Supply AIS p ECRIRE ERA ERR a 3 32 Option 40 Audio Measurements 3 34 Audio Processor Board A12 3 34 Audio Processor Interface 3 35 Inte
298. og signal enters through pins on a DB37 connector rather a mini XLR connector On Option 41 boards relays select one of the three different inputs for each channel The control signals for these relays travel on the audio signal ribbon cable but control and signal lines are isolated by ground runs From the input the analog signal is applied to NORM CAL relay In normal operation the relay is not energized and the signal passes through Cal operation is described later The audio differential signal is AC coupled to remove DC offset from the input signal Stepped Attenuator From the coupling capacitors the signal is applied to an attenuator circuit Each step of the attenuator is 10 dB The default position provides unity gain no attenuation Attenuation steps of 10 dB and 20 dB are selectable The top of the range at unity gain is 10 dBu With a 10 dB attenuator it is 20 dBu and with the maximum attenuation it is 30 dBu NOTE Load resistance is not considered in measuring dBu Similar to dBm dBu is voltage referenced only Input Amplifier After exiting the stepped attenuator the signal is applied to an input clamp circuit The clamp circuit 11 2 V input clamping protects the operational amplifier by holding its input below the supply voltage low noise performance can be degraded or circuit devices can be damaged if input voltage exceeds supply The nominal signal expected at the input to the amplifier is approxi
299. on C ontroller board This test probes the Acquisition Controller board and displays the amount of acquisition memory found on the board Thus the pass fail field will always show PASS This check is intended to allow factory personnel to verify thatthe VM700T is properly configured for the SDI option The true detected size of the acquisition memory is reported If itis 1 Mb this test will PASS or else it will FAIL The acquisition memory size detected in the above test is compared against the size detected at system boot If the two are different this test will FAIL This test was put in because at one point in the development of the SDI board mismatches of this kind were Seen SDI serial EEPROM EEPROM initialized EEPROM checksum VM700T Video Measurement Set Service Manual The serial EEPROM U 158 is used to store calibration constants Itis written by the SDI Calibration application primarily although SDI EyeDiagram also writes some additional calibration constants to it There are two tests in this group A standard library in the software is used to read and write this device The first time the device is written the library code writes the constant 5A hex to the first of 256 locations in the EEPROM The first test checks for this and fails if some other number is found in the first location Thus a failure of this test indicates that the board was never calibrated since the EEPROM was installed or replaced The sec
300. on the VM700T screen for adjusting the Analog Input board A1 amplitude and offset voltages Test Equipment Required m Digital voltmeter with 3 1 2 digit display m Non metallic flat blade adjusting tool Tektronix part number 003 1364 00 NOTE Run this procedure only if Verification Procedure 1 Measure Square wave yields incorrect results Adjusting the VM700T unnecessarily for example to get a better reading on a calibration result that is within limits can introduce errors into a functional instrument Adjusting the CalDAC 1 Press the Measure button and the Diags soft key 2 Press the CaIDAC adjustment soft key VM700T Video Measurement Set Service Manual 5 9 Adjustment Procedure Adjust the Display 3 Remove the VM700T top cover and connect the digital voltmeter to TP610 on the analog input board A1 Adjust R474 CalDac Offset on the Analog Input board for 1 2793 V Press the C button Adjust R476 CalDac Reference on the Analog Input board for 0 0000 V Press the C button Check for a 1 2777 V 0 001 V reading at TP610 Fe NS Press the Measure button to exit the CalDAC procedure 10 Power off the VM700T and replace the top cover NOTE If you performed this procedure after getting out of limit results from Verification Procedure 1 Measure Squarewave return to Procedure 1 now This procedure adjusts the display after a monitor or CPU board replacement The replac
301. onal power cords Plug configuration Option number North America Standard 125 V 15A Plug NEMA 5 15P Europe All 230V United Kingdom 230 V Australia 230 V North America 230 V S witzerland A5 230V 1 European and United Kingdom power cord options A1 and A2 also require the VM700T power line conditioning box for operation in EU countries The power line conditioner prevents power spikes from the VM700T power supply from entering the commerical power mains VM700T Video Measurement Set Service Manual 1 7 Specification Power Line Conditioner for Option A1 and A2 Power Cords Table 1 12 AC Electrical Characteristics Characteristic Description Voltage Range 230 VAC 10 207 to 253 50 60 Hz single phase CAT II Maximum Power Consumption maximum 250 Watts with VM700T 0a Fuse Rating 3 Amp 250 V Time Delay Style 3AG Steady State Input Current 1 5 Arms 9 207 VAC 1 2 Arms 260 VAC Inrush Surge Current Protected with a 3A Time Delay fuse Power Cord 161 0066 09 Euro 161 0066 10 U K 1 See the VM700T Power Requirements in Table 1 5 for the operating voltage range of the VM700T without the Power Line Conditioner box inline Usethe part numbers listed above to order a new power cord for use with the VM700T Power Line Conditioner box Table 1 13 Power Line Conditioner Mechanical Characteristics Characteristic Description Size Length 7 inches 177 8 mm Width 4 55
302. ond test reads the entire data block and computes a CRC on all butthe last 32 bits which contains the reference CRC The computed CRC is compared against the reference CRC and the testfails ifthere is a mismatch 6 107 Troubleshooting Procedures Table 6 13 SDI Option 1S diagnostic test descriptions Cont Test name SDI Ctrl Regs Description There are 5 control registers 0 4 and one status register on the SDI board All are 32 bits in size and all are readable and writable The correlation between these registers and devices on the board is as follows Control Register 0 LS 16 bits U49 MS 16 bits U50 Control Register 1 LS 16 bits U47 MS 16 bits U48 Control Register 2 LS 16 bits U51 MS 16 bits U52 Control Register 3 LS 16 bits U56 MS 16 bits U53 Control Register 4 LS 16 bits U54 MS 16 bits U55 Status Register 15 16 bits U57 MS 16 bits U58 Ctrl Register 0 4 Each control register is subjected to a write read test using the test patterns 0x55555554 OXAAAAAAAA OxFFFFFFFE 0x00000000 0x33333332 0 0 77777776 and 0x88888888 If the data written does not match the data read the test fails and a message indicating expected and actual results is printed to the console Ch Rate Bits Each of the 2 SDI channels on the board can be forced into a manual lock mode by setting the autorate bit for the channel bit 1 for channel A and bit 6 for channel B in con
303. onnecting Audio Option 41 to a Source Option 41 Audio Signal Interconnection Cable 2 20 The measurement set with Option 41 includes a 37 pin connector located on the back panel Pin assignments for the connector are listed in Table 2 1 Table 2 1 Audio Option 41 connector pin assignments Audio Input Signal Signal Shield 1 Left 1 2 3 1 Right 21 22 20 2 left 4 5 6 2 Right 24 25 23 3 Left 7 8 9 3 Right 27 28 26 1 For single ended input connect single ended inputs to a Signal pin connect Signal pin to shield Tektronix supplies a DB 37 mating connector kit with Option 41 to assemble the signal interconnection cabling The connector pin locations are shown in Figure 2 14 Refer to Option 41 Connector Installation on page 6 12 for complete installation instructions for the connector Input3 Input2 Input1 right right right a n L LEE bd yY Input3 Input2 1 left left left Male DB 37 Figure 2 14 Option 41 Triple Input Audio input connector pin locations VM700T Video Measurement Set Service Manual Operating Information GPIB Option 48 Signal Connections and Rear Panel GPIB Indicator LED VM700T Video Measurement Set Service Manual The Option 48 interface connector is a standard GPIB parallel connection with pin outs adhering to industry standards for location and output signal levels Seven LED indicators are moun
304. ons damaged parts and improperly seated transistors integrated circuits or circuit boards The remedy for most visible defects is obvious however if heat damaged parts are discovered determine the cause of overheating before replacing the damaged part to prevent additional damage Periodic checks of the transistors and integrated circuits are not recommended Repackaging the Instrument Identification Tag Repackaging Repackage the instrument in the original manner to provide adequate protection If the original packaging is not available or is unfit for use repackage and identify the instrument as described here If the instrument is to be shipped to a Tektronix Service Center for service or repair attach a tag to the instrument showing the following information m Owner with complete address and the name of the person at your firm that can be contacted Instrument serial number and a description of the service required 1 Obtain a corrugated cardboard carton whose inside dimensions are at least six inches greater than the dimensions of the instrument to allow room for cushioning The shipping carton should have a test strength of at least 2775 pounds 2 Surround the instrument with polyethylene sheeting to protect the finish 3 Cushion the instrument on all sides by tightly packing dunnage or urethane foam between the carton and the instrument Allow three inches on all sides for cushioning 4 Sealthe carton
305. ont Porch Duration 0 5 us to 2 us 10 ns Horizontal Blanking Horizontal Blanking Width 6 hs to 30 hs 10 ns Horizontal Blanking Horizontal Sync Rise and Fall Time 80 ns to 120 ns 10 ns to 30 ns Horizontal Blanking 120 ns to 300 ns 20 ns 300 ns to 1 0 us 30 ns Horizontal Sync Width 1 us to 8 us 10 ns Horizontal Blanking Table 1 76 FCC vertical blanking interval timing Sync to Setup Sync to End of Burst Measurement Range Accuracy Test signal Equalizing Pulse Width 25 to 100 of nominal 0 3 Vertical Blanking horizontal sync pulse width Serration Width 1 hs to 20 us 10 ns Vertical Blanking Vertical Blanking Width 19 lines to 29 lines 0 1 lines to 40 2 lines Vertical Blanking Table 1 77 Amplitude and Phase measurements Measurement Range Accuracy Test signal Average Picture Level APL 0 to 20096 3 0 Full Field Bar Top 0 to 90 of Maximum Carrier 0 1 FCC NTC 7 Composite Bar Amplitude 0 to 200 IRE 0 3 IRE FCC NTC 7 Composite Chrominance to Luminance 300 ns 5 ns FCC NTC 7 Composite Delay Relative Chroma Time Chrominance to Luminance 0 to 160 1 FCC NTC 7 Composite Gain Relative Chroma Level Differential Gain 0 to 100 0 3 FCC NTC 7 Composite VM700T Video Measurement Set Service Manual 1 25 Specification Table 1 77 Amplitude and Phase measurements cont Measurement Differential Phase Luminance Non linear Distortion Relative Burst Gain
306. or of 256 was used to create the reference Range specifies the extremes between which a measure ment can be made Measurement Range Absolute mode accuracy Relative mode accuracy Bar Level b1 or Back Porch 300 mV to 1 4 V 30 5 0 2 9ync Level 50 mV to 600 mV 10 596 0 2 Sync to Bar Top 350 mV to 2 V 10 59 0 2 Sync Bar Ratio 10 to 125 0 5 0 2 100 nominal Bar Tilt Rec 569 0 to 20 0 2 0 1 Line Time Distortion Rec 567 Bar Width Table 1 16 Bounce Measurement Accuracy Peak Deviation 0 to 50 1 Settling Time 0 to 10 sec 100 msec 1 10 VM700T Video Measurement Set Service Manual Specification Table 1 17 Burst Frequency Measurement Range Relative mode accuracy Burst Frequency 100 Hz 0 5 Hz Table 1 18 Chrominance to Luminance Measurement Absolute mode accuracy Relative mode accuracy Chrominance to Luminance Delay 300 ns 5 ns 1 0 ns Chrominance to Luminance Gain Ratio 0 to 160 31 0 30 1 Table 1 19 Chrominance Noise Measurement Range Absolute mode accuracy AM Noise 20 dB to 80 dB 1 dB 20 dB to 60 dB PM Noise 20 dB to 70 dB 1 dB 20 dB to 60 dB Table 1 20 Chrominance Nonlinearity Measurement Absolute mode accuracy Relative mode accuracy Chrominance Amplitude 0 to 10096 10 59 Chrominance P hase 0 to 360 10 2 Chrominance to Luminance 50 to 45096 0 2 0 2 Intermodulation Table 1 21 ColourBar Measurement
307. ormance testing to SMPTE 259M and SMPTE 165 digital error detection and reporting m data analysis with data distribution display m Relative to reference mode allowing signal comparisons W Digital video wander measurements GPIB Interface Option 48 This option provides the hardware and firmware to support a GPIB interface for remote control of the VM 700T or hard copy output to a GPIB printer White Phosphor CRT Option 74 This option provides a display module with a white phosphor CRT instead of the standard green phosphor when a new instrument is ordered with Option 74 from the factory All the display module adjustments are the same as those for the standard CRT 7 4 VM700T Video Measurement Set Service Manual Cabinet and Mounting Options Option 1C VM7FR1 VM7FC1 Cabinet Version Option 1C Rack Mounting Kit VM7FR1 Cabinetizing Kit VM7FC1 This option provides the VM700T in a cabinet version from the factory The standard order configuration is rack mounted This field installable option provides a rack mounting conversion kit for the VM700T This kit converts a cabinetized measurement set to permit a rack mounting installation This field installable option provide a conversion kit to install a cabinet on a rack mounted measurement set Auxiliary Software Options VMBKUP VMREMGR VMBKUP VMT VMREMGR Optional Accessories This software package assist
308. ors file refer to High Level Diagnostic Errors File on page 6 84 To stop DiagsLoop execution press the Abort Looping soft key VM700T Video Measurement Set Service Manual 6 77 Troubleshooting Procedures Diagnostics Selection File The Diagnostics Selection file allows you to specify the high level diagnostics that run during Powerup Diagnostics or Diags Loop When the VM 700T is powered on with diagnostics enabled to run not Quick Start the diagnostics selected in the Diagnostics Selection file are run The contents of the Diagnostics Selection file are shown in Figure 6 54 Power Up Diagnostics Selection Genlock Diagnostic Controller Diagnostic Acquisition Diagnostic ADC Diagnostic AnalogInput Diagnostic FilterBoard Diagnostic AudioProcessor Diagnostic AudioAnalog Diagnostic GPIB Diagnostics Selected Line 6 Not Selected Figure 6 54 Power up diagnostics selection display diagnostic routines on the Selected side execute during Powerup Diagnos tics or Diags Loop To select or unselect a diagnostic from the Diagnostics Selection file do the following steps 1 Press the Configure button 2 Press the Configure Files soft key 3 Select the Diagnostics Selection file 4 Turn the control knob until the diagnostic s name is highlighted Touching the vertical center of the left half of the screen selects the highlighted diagnostic touching the vertical center of the right half unselects it 5 Press
309. ot Selected Figure 4 5 Diagnostic selection file showing an unselected choice 1 The AudioProcessor Diagnostic and AudioAnalog Diagnostic selections are available only with the VM700T Audio option GPIB Diagnostics is added to this list when the GPIB option is installed 4 4 VM700T Video Measurement Set Service Manual Performance Verification Diagnostic Errors File When high level diagnostics are run any errors detected are written to the Diagnostic Errors file The contents of this file can be printed using the Print File soft key or the file can be deleted using the Delete soft key If diagnostic errors appear refer to the Diagnostics information starting on page 6 55 The maximum capacity for the Diagnostic Errors file is 100 lines If the number of errors detected causes the file to exceed this length the earlier results are scrolled out of the file buffer When this occurs the Diagnostic Errors file includes a message stating that some of the text has been scrolled out of the file VM700T Video Measurement Set Service Manual 4 5 Performance Verification Test Equipment Required The test equipment to use for performing the verification procedures is shown in Table 4 1 Test equipment suggestions for use in doing the verification procedure are given in the example column The examples given are based on the test equipment that many customers and the Tektronix service centers have installed for supporting the VM70
310. oving the board s Replacement retainer screws With the screws removed the board may be lifted from the VM700T chassis and set aside Replacing the board is the reverse of this procedure You may use the following procedures to remove and replace the analog input board Required Tools Use the following tools to remove the Analog Input circuit board W Pozidriv screwdriver 1X 2X Procedure Use the following procedure to remove and replace the Analog Input board 1 Perform the following steps to remove the Analog Input board a Remove the top cover panel refer to Cover Panel Removal and Replacement on page 6 8 b Disconnect the wire at J132 and the shielded cable at J6 and move them aside see Figure 6 14 for cable locations Disconnect the ribbon cable at J965 d Disconnect the power bus cable at its five connectors and then remove the cable e Remove the wire connecting A4 J915 to Al J922 at the J922 end only f Remove the wire connecting A4 J418 to A1 J923 at the J923 end only g Atthe back of the instrument remove the screws holding the signal input connector to the instrument rear panel see Figure 6 15 h Remove the eight board retaining screws seven on the perimeter and one in the center and carefully lift the board from the VM 700T chassis VM700T Video Measurement Set Service Manual 6 23 Maintenance 132 J6 1 1965
311. p the Diagnostics Configuration menu shown in Figure 6 47 In this menu highlight and select P in the Set Diagnostics Powerup Mode line to bring up the power up mode choices shown in Figure 6 48 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection DIAGNOSTICS CONFIGURATION MENU Key Selection P Set Diagnostics POWERUP MODE I Set Diagnostics INTENSITIES B Set Low Level Diagnostics BAUD RATE Reprint 8 Abort Menu Input your selection Figure 6 47 Diagnostic configuration menu 6 70 VM700T Video Measurement Set Service Manual Troubleshooting Procedures In the Set Diagnostics Powerup Mode menu shown in Figure 6 48 highlight select Q to have the instrument skip diagnostics on power up or highlight and select P to have the instrument run the diagnostics on power up The remaining choices are used in diagnostic testing in manufacturing and factory service When a selection is made the choice is stored in the diagnostics NVRAM and the Diagnostics Configuration menu returns At this point the quickest way to start the instrument for normal operation is to turn off the VM700T and turn it back on again You can also use the Abort Menu selection to back up the menu tree to the VM700T Startup Menu and then select one of the run modes to restart the VM700T Low Level Diagnostic Interface knob moves cursor Select Line inputs selection SET DIAGNOSTI
312. paid Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located Customer shall be responsible for paying all shipping charges duties taxes and any other charges for products returned to any other locations This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate main tenance and care Tektronix shall not be obligated to furnish service under this warranty a to repair damage resulting from attempts by personnel other than Tektronix representatives to install repair or service the product b to repair damage resulting from improper use or connection to incompatible equipment c to repair any damage or malfunction caused by the use of non Tektronix supplies or d to service a product that has been modified or integrated with other products when the effect of such modification or integration increases the time or difficulty of servicing the product THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE TEKTRONIX RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT S
313. plitude to chopper reference ampli tude Offset is the difference between acquired signal midpoint and ADC midrange value ADC bit patterns Cal signal paths Tests for walking 1 and walking 0 bit patterns in DAC sample data DAC and chopper signals are routed via all possible paths to the ADC with gain and attenuation set to 0 to verify continuity and separation of the two input channels Attenuator steps Signals from the DAC are routed through the available attenuator steps acquired by the ADC and analyzed Attenuation is the ratio of atten off to atten on voltage Gain steps Signals from the DAC are routed through the available gain stages acquired by the ADC and analyzed Gain is the ratio of gain on to gain off voltage Notch filters DAC signals are routed through the notch filters and gain is measured as the ratio of notch on to notch off voltage Left flatness Tests left channel flatness with sine waves generated by the DAC gain and attenuation Right flatness are 0 dB and the notch filter is off Tests right channel flatness with sine waves generated by the DAC gain and attenuation are 0 dB and the notch filter is off 6 98 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Troubleshooting Option 48 GPIB Troubleshooting the GPIB board consists of running the GPIB diagnostics The GPIB Diagnostic routine does extensive testing of the interface hardware Failure of any
314. processor that is loosely coupled to the main processor in the VM 700T by interrupts and shared memory The shared memory and the interprocessor communications register IPC register are accessible by either processor and are used to communicate between the processors Besides the shared memory spaces the GPIB processor has some private RAM space that is not directly accessible by the VM 700T processor The private RAM space is used by the GPIB processor as stack space to hold local variables and intermediate results Another section of the memory space is the program RAM area It is treated as ROM space by the GPIB processor and cannot be written to by the GPIB processor The operating code for the GPIB board is store in the ROM of the VM700T On initialization a copy of that code is loaded into the program RAM space of the GPIB processor by the VM 700T processor It is not possible for the two processors to access the shared memory at the same time Either one or the other processor can access the shared RAM space or the IPC register Both the shared RAM and the IPC register share the same controlling hardware The Dual Port RAM controller has arbitration circuitry that controls accesses to the shared memory space to prevent contention When both processors are accessing the shared space this circuitry alternates accesses so neither processor blocks the other from the shared memory space VM700T Video Measurement Set Service Manual 3 45 Theo
315. put level setting Let the display stabilize Adjust the Chroma Filter Flatness adjust so that the change in amplitude Delta Amp is within 0 02 of the reference level stored in step 4 Disconnect the cables and test equipment from the VM700T VM700T Video Measurement Set Service Manual Adjustment Procedure Adjust ADC Gain The ADC gain is auto calibrated during normal VM700T operation This check and adjustment should only be done as part of a board exchange repair to set the adjustment to a nominal setting for auto calibration Test Equipment Required m Non metallic flat blade adjusting tool Tektronix part number 003 1364 00 Adjusting ADC Gain 1 Press the Measure key then the Diags and the ADC Gain Adjust soft keys 2 VM700T should display 100 3 NOTE If the VM700T meets the limits described skip step 3 Adjusting the VM700T unnecessarily for example to get a better reading on a calibration result that is within limits can introduce errors into a functional instrument 3 Ifthe number displayed is outside the tolerance range remove the top cover of the VM700T and carefully adjust R21 ADC Gain on the ADC board to bring the number to 100 See Figure 5 1 on page 5 5 for the adjustment location Adjust the Calibration This procedure adjusts the calibration DAC Run this procedure by selecting it DAC CalDAC with the soft key in the Diags directory Follow the directions displayed
316. r ns 160 jitter frequency KHz for frequencies below 160 kHz 360 Mb s 0 8 ns pk to pk for frequencies of 160 kHz Cable Length Maximum for No Equivalent to 200 meters of Belden 8281 Bit Errors cable and above Max jitter ns 130 jitter frequency KHz for frequencies below 160 kHz Equivalent to 250 meters of Belden 8281 cable typical 1 40 VM700T Video Measurement Set Service Manual Specification Table 1 105 SDI Ch B Input Characteristic Electrical Characteristics Input type Return Loss PowerOn Power Off Signal Characteristics Amplitude Range Performance requirement BNC 75 terminated z 25 dB 1 MHz to 360 MHz gt 15 dB 1 MHz to 360 MHz 800 mV 1596 25 Supplemental information Channel on or off Frequency Range 143 Mb s 20 ppm 270 Mb s 20 ppm 360 Mb s 20 ppm J iter Maximum for No Bit Errors 143 Mb s 2 ns pk to pk for frequencies of 160 kHz and above Max jitter ns 320 jitter frequency KHz for frequencies below 160 kHz 270 Mb s 1 ns pk to pk for frequencies of 160 kHz and above Max jitter ns 160 jitter frequency KHz for frequencies below 160 kHz 360 Mb s 0 8 ns pk to pk typical for frequencies of Cable Length Maximum for No Bit Errors Table 1 106 LTC Input Characteristic Electrical Characteristics Input type Input Impedance Signal Characteristics Format Equivalent to 200 meters of Belden 8281 cable Performance requirement Mi
317. rates with line frequencies of 50 Hz or 60 Hz over two line voltage ranges The nominal setting of the low voltage range is 115 VAC The nominal setting of the high voltage range is 230 VAC There are two power switches on the measurement set m The main power switch is on the rear panel above the power cord receptacle m Stby On switch is on the front panel Both power switches must be on to operate the measurement set when the rear panel power switch is on regardless of the position of the front panel power switch Do not operate the measurement set with any covers removed Refer all servicing of the measurement set to a qualified service person WARNING Dangerous voltages are present within the Power Supply module VM700T Video Measurement Set Service Manual 2 1 Operating Information 2 2 Changing Line Voltage Range and Fuse A Power Cord Power Line Conditioner Accessory The voltage range selection switch and fuse holder are located in the lower left corner of the rear panel see Figure 2 10 on page 2 16 The measurement set is shipped from the factory set to the operating voltage of the destination 115 VAC or 230 VAC If the setting is not correct you must change it before connecting the power cord to the power source Set the voltage range selection switch located on the rear panel of the measurement set to the correct position for operation CAUTION When changing the line voltage sele
318. ratures up to 31 C decreasing linearly to 50 to at 40 C Equipment Type Testand Measuring Safety Class Class as defined in IEC 1010 1 Annex grounded product Overvoltage Category Mains Overvoltage Category II as defined in IEC 1010 1 Annex Local level mains appliances portable equipment Pollution Degree Pollution Degree 2 as defined in IEC 1010 1 Do not operate in environments where conductive pollutants may be present Note Rated for indoor use only Table 1 10 Rear panel signal connectors Characteristic Description Port 0 and Port 1 Connectors DB 9 male connectors configured as RS 232C DTE ports to provide hardcopy output to serial printers and remote control GPIB Connector Option 48 Meets electrical specifications described in IEE E 488 for parallel GP IB connectors VGA Connector 15 pin D type Outputs VGA signals Parallel P rinter Connector DB 25 female Centronics compatible connector and signals Remote Contact Closure Relay Alarm Contacts are not debounced Maximum Current 50 mA 1 6 VM700T Video Measurement Set Service Manual Specification Table 1 10 Rear panel signal connectors Cont Characteristic Description Maximum Voltage 30 VACgnyus or 30 VDC Control Logic Set GRLY 1 closes the relay Set GRLY 0 opens the relay CH A CH B CHC and Ext Sync BNC 75 Termination required when not used as feed through signal path Feed Through Connectors Table 1 11 Opti
319. rdering the VM 700T you may specify the video standard you what your instrument to be capable of making measurement with Option 01 is the System M NTSC video standard and Option 11 is the System BG i PAL video standard You may also order the VM 700T with both standards installed or purchase a firmware upgrade to add a standard to make the VM 700T dual standard Video Measurement Set Application Options Option 1G Option 20 Option 21 Option 30 Option 42 2T Echo and Rounding of Black and White Measurement Option 1G Teletext Measurement Option 20 Camera Measurements Option 21 The application options provide additional measurement capabilities not provided in the standard Option 01 NTSC or Option 11 PAL firmware as part of the base instrument measurements These may be ordered as part of the original purchase or added later with an option upgrade The VM 700T Video Measurement Set Option 1G 2T Echo and Rounding of Black amp White gives you access to two measurements named Echo and Rounding Errors respectively Echo determines multipath distortion Rounding Errors measures rounding of the black to white and white to black signal transitions The VM700T Video Measurement Set Option 20 Teletext gives you access to two measurements Teletext and SoundInSync These measurement applications determine various parameters related to the transmission of digital information in the vertical interval and in the sync pulse
320. re 2 3 Touch screen calibration display 2 6 Figure 2 4 Touch screen calibration 1 2 6 Figure 2 5 Panel calibration values 2 6 Figure 2 6 Diagnostic configuration Menu 2 7 Figure 2 7 Set diagnostics power up mode menu 2 8 Figure 2 8 The VM 700T Video Measurement Set front panel 2 11 Figure 2 9 Measurement set keypad 2 12 Figure 2 10 VM700T Video Measurement Set rear 1 2 16 Figure 2 11 Video signal input connectors 2 18 Figure 2 12 Cables and connectors supplied with Audio Option 40 2 19 Figure 2 13 Option 40 connectors pin assignments 2 19 Figure 2 14 Option 41 Triple Input Audio input connector pinlocations 2 20 Figure 2 15 GPIB board rear panel 2 21 Figure 2 16 VM700T rear panel with Option 1S installed 2 23 Figure 2 17 Option 1S rear 2 23 Figure 3 1 Analog input board A1 block diagram 3 4 Figure 3 2 Genlock board A2 block diagram 3 8 Figure 3 3 ADC board block diagram 3 12 Figure 3 4 Filter switch board A4 block diagram 3 15 Figure 3
321. red to the three stereo inputs of the VM 700T Either Option 40 or Option 41 may be installed in the VM 700T not both VM700T Video Measurement Set Service Manual 7 3 Options Serial Digital Interface Option 15 Option 15 provides the capability to display capture and analyze 270 Mbit 525 line and 625 line serial component 143 Mbit serial composite and 360 Mbit serial component digital video signals The Option 1S hardware consists of an SDI circuit board that installs into the right side card cage a two board input assembly that mounts onto the measurement set rear panel updated instrument firmware and several interconnecting cables The Option 15 rear panel connectors include two SDI inputs one loopthrough and one internally terminated in 75 2 a buffered SDI output of one of the SDI input channels an AES EBU digital audio input a Longitudinal Time Code input for time stamping logged error files and an analog loopthrough input to be used for a timing reference signal Option 15 provides the following key features Automatic analysis of 270 Mbit component 143 Mbit composite and 360 Mbit component serial digital video signals m Continuous real time format analyzer with event logging and frame capture captured frames can be downloaded to a PC m Longitudinal Time Code input for time stamping error events External and embedded digital audio measurements including audio to video timing measurements m Conf
322. requested and storing the current setting the VM700T displays a second set of instructions as shown in Figure 2 4 Follow the directions given in the screen After you have touched the dots at all four corners a screen showing the panel calibration factors is displayed see Figure 2 5 From that screen you can press any key to return to the startup menu VM700T Video Measurement Set Service Manual 2 5 Operating Information TOUCH PANEL INTERFACE CAL DISPLAY Use the knob to adjust horizontal position and squareness of the screen border lines Press AUTO button to abort or any other to accept and store current setting Current Setting 14 Figure 2 3 Touch screen calibration display TOUCH PANEL INTERFACE CAL PANEL press AUTO to abort TOUCH THE DOT INSIDE THE SQUARE Place finger tip directly over the dot being careful to avoid parallex touching the dot until the square highlights and beeper sounds SQUARE LOCATIONS SEQUENCE SQUARES will appear near Screen the screen corners 1 2 SEQUENCE will be 1 2 3 4 3 4 as indicated to the right Figure 2 4 Touch screen calibration panel PANEL CALIBRATION VALUES XSCALE 471 XOFFSET 292 YSCALE 398 YOFFSET 231 Press Any Key to Continue Figure 2 5 Panel calibration values 2 6 VM700T Video Measurement Set Service Manual Operating Infor
323. right side card cage refer to CPU Board A5 Removal and Replacement on page 6 15 c Remove the Acquisition Memory board refer to Acquisition Memory Board 18 Removal and Replacement on page 6 18 d Remove the I O board refer to 1 Board A20 Removal and Replace ment on page 6 9 e Remove any installed option boards refer to Option 40 and Option 41 Audio Boards A12 A13 and 17 Removal and Replacement on page 6 11 and Option 48 GPIB Interface Board A19 Removal and Replacement on page 6 14 for more information f From the top of the instrument disconnect the power bus cable at its five connectors and then remove the cable g From the bottom of the instrument remove the connectors and terminal wires between the power supply and the Interconnect board assembly h Inside the left card cage remove the six screws holding the Interconnect board assembly to the card cage back panel see Figure 6 25 NOTE The Interconnect board assembly retaining screws are easier to remove if you first place the instrument on it s right side and then use a long shank screwdriver allowing more hand clearance to remove them i With the instrument placed upside down carefully push the power supply wiring aside and move the Interconnect board assembly up and out of the chassis 2 Replace the Interconnect board assembly by performing step 1 in reverse order VM700T Video Measurement Set Service Manual Maintenan
324. rnal and external sync with the genlock configured for the opposite standard Then the genlock is configured for the standard being tested and time to lock is measured NTSC or PAL VCO Lock Controller portion of the Control R egisters Checks mode Genlock configuration Genlock status and filter control Acquisition Memory registers with 8 bit walking 1 and walking 0 patterns Checks analog A18 input register for writeability no bus errors Checks DVM readback register for readability Overrange Detector Checks bit 4 of the Controller interrupt register ADC output is latched high to force the bitto set and latched low to clear it Successful completion of 5 Clock Detector Checks bit 2 ofthe Controller interrupt register Disables the sample these test require that Clock to cause the bitto set then re enables the sample clock to clear the Genlock board A2 the bit be operating correctly 6 Clamp Counters A C Checks the counter chips Performs walking 1 and walking 0 tests and Acq Sig Counters read and write and checks countdown over several reads Sig0 Sig2 Register File State Machine Settings Checks SRUN and TRUN lines of the dynamics RAM control data Trigger and Sequence and address lines ofthe trigger RAM Runs a checkerboard pattern RAM test on the trigger RAM Tests state machine sequence RAM Acquisition portion ofthe 9 RAM Fills RAM with psuedo random sequence then reads and ver
325. rrupt Generator Status Port scies sae i habs 3 35 DSP Processor and Interface 2 2222 5222 2 2 242 yen is 3 36 Audio Data vet ire RR RE p RUE 3 36 Static RAM 3 36 ii VM700T Video Measurement Set Service Manual Table of Contents Audio Analog Board A13 400 Hz Notch Filter DAC Output Option 40 A D Converter Audio Board Control Floating Power Supply Option 41 Audio Analog Board Option 48 GPIB Interface Board 19 Option 1S Serial Digital Measurements Performance Verification Self Diagnostics Test Equipment Required System Verification Procedures Audio Option Verification Procedure Test Equipment Required Audio Option 40 Verification Procedure Check Level Measurement Accuracy and Flatness Check Distortion and Distortion Measurement Accuracy Check Frequency and Phase Measurement Accuracy Audio Option 41 Triple Input Verification Procedure Configuring Source Selection Audio Check Level Measurement Accuracy and Flatness Check Distortion and Distortion Measurement Accuracy Check Frequency and Phase Measurement Accuracy
326. rter outputs and unclocked to minimize delays Output Latch The output latch supplies differential drive for the cable transporting the data to the acquisition controller The latch is set and reset by ASYNC SET and ASYNC RESET from the acquisition controller board It is clocked by the OUT LATCH clock derived from the 4FSC signal VM700T Video Measurement Set Service Manual 3 11 Theory of Operation 42 5 V and 2 5 V REGULATORS FLATNESS ADJUST COMP ADC IN TEST POINT SIGNAL CONDITIONING AMPL e GAIN ADJUST SIGNAL IN VREF SAMPLE CLK OUTPUT LATCH BUFFERS SAMPLE CLK 00 0 0 DETECTOR CC 9 b9 SITION OUTLATCH OVERRANGE 9AMPLE CKD DIGITAL CKD ASYNC SET ASYNC RESET LINE OUT LINE OUT FRAME OUT FRAME OUT CC LINE AND FRAME PULSE PIPELINE VM700T Video Measurement Set ASYNC SET ASYNC RESET ND Service Manual Theory of Operation Line and Frame Pulse and V sync from the GenLock board are applied to the Line and Frame Pipeline Pulse Pipeline The pipeline is a series of flip flops that delays the frame and line sync by the same amount as the A D converter delays the video Overrange Detector Overrange detector checks to see if the
327. ry of Operation D0 31 VM 700 J 100A B C to VM 700T 10 GPIB Connector GPIB Status Indicators Figure 3 18 Simplified block diagram of the GPIB interface option board 3 46 D0 31 VM 700 ain Processor Decodi ng VM 700 Main Processor Dual P ort Memory Interface Main BA0 25 Processor Address Buffers A0 31 3 VM 700 Main Processor Access DPRDO 31 Control amp GPIB Timing Processor Dual P ort Memory Interface gt Control 3 7 Signals Decoding Timing and Watchdog 1 23 BA0 25 DPRA2 21 Dual Port DPRDO 31 Memory Dual Port Controller Memory MRAO 9 IR W Timer ID0 15 GPIB Interface 141 23 141 23 DPRD0 31 DPRA2 21 Inter processor Communication Register SYS RESET Reset and Halt Generation and General Control IA1 23 100 15 System Clock Tick Debug RS 232 and Forced Inst Buffers Register VM700T Video Measurement Set Service Manual Theory of Operation The GPIB processor has no memory cache so it gets its program instructions from the program RAM space Most of the remaining access time the GPIB processor is doing reads and writes to and from t
328. s 1 25 Frequency Response measurements 1 26 Incidental Carrier Phase Modulation 1 26 Color Bar measurements 1 27 Out of Service measurements 1 27 Waveform Distortion measurements 1 27 VIRS measurements 1 27 Signal to Noise Ratio measurements 1 28 O 33 Automatic audio test measurement specifications 1 29 Tektronix automatic audio test measurement specifications 1 30 Frequency and Noise specifications 1 31 Accuracy and Flatness specifications 1 32 General Audio Spectrum specifications 1 32 Audio Spectrum Level measurement specifications 1 32 Harmonic Analyzer measurement specifications 1 33 Miscellaneous specifications 1 33 Multitone Analyzer measurement specifications 1 33 Audio Video Timing measurement specifications 1 34 VM700T Video Measurement Set Service Manual Table of Contents Table 1 95 IEEE 488 1 interface functions implemented in the VM700T GPIB interface Table 1 96 GPIB Electrical characteristics Table 1 97 Mechanical specifications Table 1 98 Optional accessories Table 1 99 SDI
329. s board you must first remove the right side cover and the card cage retainer You must also disconnect five cables from the circuit board Required Tools Use the following tools to remove the Option 1S hardware m Flat blade screwdriver 3 16 or inch blade W Pozidriv screwdriver 1X 2X VM700T Video Measurement Set Service Manual 6 19 Maintenance SDI Board Use the following procedure to remove and replace the Option 1S SDI circuit board 1 Perform the following steps to remove the SDI board a Remove the right side cover panel refer to Cover Panel Removal and Replacement on page 6 8 Remove the card cage retainer refer to step 1 on page 6 16 The SDI board occupies the second from the top slot in the right side card cage see Figure 6 10 on page 6 17 To remove this board you must first disconnect five cables from the board Disconnect the cables from the SDI board at J8 J7 J10 and J5 see Figure 6 12 Spread the cable ejector tabs to disconnect the cable from the SDI board at J3 Unplug the circuit board using the ejector tab to release the board from the main interconnection board When the circuit board 15 loose slide it out of the card cage 2 Perform the following steps to replace the SDI board a Guide the SDI board onto the second from the top right side card cage track and slide it into the card cage connector Align the circuit board connector pins with the main interconnection
330. s in backing up the VM700T user created files These files can be reloaded to the same instrument or to another VM700T to generate a common set of configuration files This software package assists in remote control of the VM700T using a personal computer The software also allows you to capture text and graphics This software package aids you in handling the graphic displays and transferring them to a personal computer for filing display or printing Table 7 1 Optional accessories Tektronix part or Accessory Description product number Service manual VM700T servicing information 070 9630 XX GPIB accessories Available with Option 48 Cables 1m double shielded 012 0991 01 2 m double shielded 012 0991 00 3m double shielded 012 0991 02 GURU 11 GPIB User s Resource Utility for the Personal S3FG100 Computer This package includes software and manual plus National PC2A GPIB controller board GPIB cable software on floppy diskettes VM700T Video Measurement Set Service Manual 7 5 Power Options Table 7 2 Optional power cords Plug configuration Option number North America Standard 125 V 15A Plug NEMA 5 15P Europe All 230V United Kingdom A21 230V North America 230 V S witzerland 230 V European and United Kingdom power cord options A1 and A2 also require the VM700T Power Line Conditioner box for operation in EU countries The power line conditioner preven
331. selection INSTRUMENT RUN MODES MENU The instrument will be reset to run in the mode selected below overriding current boot switch settings Key Selection Current Powerup Mode is QUICK START abort this menu and go to the DIAGNOSTICS CONFIGURATION MENU to change it P aoe POWERUP IDIAGS 4 cover rrr rrr Da Diagnostics start Instrument Q aso QUICK START Skip Diagnostics start Instrument L LOW LEVEL DIAGS LOOP Loop on Low Level Diagnostics D HIGH LEVEL DEBUG Start Instrument in HL Debug Mode AUTORESET iii so rer nes Do EXTRA Diagnostics start Instrument Reprint 8 Abort Menu Input your selection Figure 6 49 Instrument run modes menu From this menu you can override the normal powerup settings and start up the VM700T in any of the indicated start up modes for one time The Autoreset choice runs all the diagnostics prior to initializing and it is a good choice when running the Verification procedure 6 72 VM700T Video Measurement Set Service Manual Troubleshooting Procedures VM700T Boot Switch and Boot switch is located at rear outer corner of the CPU board when viewed Diagnostic LED facing the right side of instrument and looking down at the CPU board In Figure 6 50 the Boot switch is shown in the Normal setting That is with all switches set to the CLOSED position pushed in at top This is the normal setting for
332. shooting the CRT 6 94 Display The display module is a 9 inch diagonal 640 x 480 pixel monochrome CRT unit The display is adjusted at the factory for optimum viewing brightness The interactive touch screen is attached in front of the CRT It can be removed for replacement of the touch screen or the display module if necessary If the CRT display fails the faulty unit must be removed and replaced For information on replacing the CRT display module refer to Removing and Replacing Display and Control Components on page 6 32 When a CRT display module is replaced minor adjustments may be necessary to center the display or fine adjust its brightness level Refer to Adjusting the Display on page 5 10 if readjustment is needed Part of the Touch Screen calibration procedure also makes some adjustments to the display If you replace the touch screen perform the touch screen calibration procedure on page 6 68 Isolating a CRT Display Fault Two types of CRT display failures can occur No display blank screen No display and POWER SUPPLY FAIL LED lit For no display blank screen CRT display symptoms follow this procedure 1 Connect an external monitor to the rear panel connector If there is no display on the external monitor the problem may be in the CPU or display driver circuitry on the CPU board Exchange the CPU board with a known good one to see if the display returns If there is a VGA output display
333. soldering or replacing components To avoid electric shock do not touch exposed connections X Radiation To avoid x radiation exposure do not modify or otherwise alter the high voltage circuitry or the CRT enclosure X ray emissions generated within this product have been sufficiently shielded VM700T Video Measurement Set Service Manual XV Service Safety Summary xvi VM700T Video Measurement Set Service Manual Preface This is a service manual for the VM700T Video Measurement Set It is a module level repair manual for use by a qualified service person in the isolation of faulty modules and repair by module exchange Contents of the Manual This manual contains the following sections 1 10 Specification lists the major specifications of the VM700T as an instrument Option specifications are contained in the associated Option User Manuals Operating Information introduces the VM700T gives the basic installation instructions describes its major features and the controls and connectors of the instruments Theory of Operation contains functional block descriptions of the VM700T circuit board modules to aid in understanding the instrument for servicing Performance Verification has the procedures for verifying the operation of the VM700T and the audio options Adjustment Procedure has the procedures for returning the VM700T to specification after a circuit board module exchange Maintenance provides the custom
334. solution 0 1 dB Frequency Range 20 Hz to 20 kHz Accuracy 1 Hz for input gt 60 dBu Resolution 1 Hz for input gt 60 dBu Phase Difference Minimum input level for Specified accuracy Phase measurement error 40 dBu 1 for inputs at 40 Hz to 20 kHz 12 for inputs at 40 Hz to 20 kHz Total harmonic distortion amp noise THD N Measurement bandwidth Input level Residual THD4N Maximum measurement Accuracy Channel S eparation 33 Hz to 22 kHz 2 20 dBu lt 0 0396 70 0 10 of reading 1 digit for harmonics Measurement Window 24 Hz Measurementis taken in the undriven 20 Hz to 350 Hz 96 Hz channel The measurement window follows the driven channel signal frequency 2350 Hz Constant bandwidth Measurement F ilter Plot Mode Minimum frequency change 2Hz Minimum dwell time 1 sec for input frequencies lt 500 Hz 500 ms for input frequencies 2 500 Hz VM700T Video Measurement Set Service Manual 1 31 Specification Table 1 88 Accuracy and Flat ness specifications Accuracy includes Frequency range Level range 1 flatness Flatness 20 40 Hz gt 20dBu 0 3 0 2 dB 0 1 0 2 dB 20 dBu to 50 dBu 0 4 0 3 dB 0 1 0 2 dB 50 dBu to 60 dBu 0 6 0 5 dB 0 1 0 2 dB 60 dBu to 70 dBu 1 0 dB 0 1 0 2 dB 40 Hz 20 kHz gt 20 dBu 0 2 dB 0 1 dB 20 dBu to 50 dBu 0 3 dB 0 1 dB 50 dBu to 60 dBu 0 5 dB t 0 1 dB 60 dBu to 70 dBu 1 0 dB 0 1 dB 1 Level
335. ss of Signal message replace the SDI board NOTE Various user settings can dramatically alter the displayed waveform in ways that may appear to indicate a malfunctioning circuit In the SDI Waveform application these user settings include Menu selections of Style Display Display Diff Free Run as well as the front panel controls of Move and Expand Verify these settings before assuming a malfunction exists 5 Swap the SDI Ch A and SDI Ch B cable connections on the SDI board at J7 and 18 see Figure 6 65 6 Connect the signal input to the SDI Ch B input connector leave the VM700T front panel set to display the channel A signal 7 Check that there is a signal display 8 Ifthere is still no signal display on channel A replace the SDI board 9 If there is a signal display on channel A 10 Check J5 pin 9 for 13 to 15 VDC see Figure 6 65 11 Check J5 pin 10 for 13 to 15 VDC 12 If one or both voltages are bad replace the SDI board 13 If both voltages are good remove the SDI Rear Panel Interface assembly 14 Check that the cables are properly seated in their connectors on the SDI Rear Panel Interface assembly 15 Disconnect the flat cable and the green channel A cable from the SDI Rear Panel Interface assembly 16 Check each of the wires in the flat cable and the green cable for continuity 17 If the cables are good replace the SDI Rear Panel Interface assembly VM700T Video Measurement Set Ser
336. ssing and holding certain of the front panel buttons at power on These are referred to as the backdoor boot modes The choices are shown in Figure 6 39 Bypassing the Power Up Diagnostics The factory Quick Start default bypasses the power up diagnostics to shorten the power up sequence but it also prevents the VM 700T from performing self tests at power up If the startup diagnostics have been reconfigured to run at power up they can be bypassed from the front panel at power on To bypass all power up diagnostics both low level and high level when the VM700T is not configured for Quick Start press and hold the Waveform button when you power on the VM 700T Release the button after the VM700T beeps twice in about 10 seconds VM700T Video Measurement Set Service Manual Troubleshooting Procedures The 700 displays the message Startup in Quick Start Mode Recognized Another message indicating all the diagnostics are being bypassed is then displayed and the VM700T proceeds with system initialization To bypass each user selectable diagnostic as each begins to run or at any time during the running of the diagnostic press the Abort Diagnostic soft key The VM700T proceeds to the next selected diagnostic in the Diagnostics Selection file After the last selected diagnostic either runs or is aborted the VM 700T proceeds with system initialization Low Level Diagnostic Interface SPECIAL INSTRUMENT POWER UP MODES Th
337. step requires a 67 5 MHz clock that must meet the specifications listed in Table 5 4 on page 5 21 or you will misadjust the instrument If you are using the module of the TG2000 Signal Generation Platform as the clock source you must use the Clock Out connector on the module or you will misadjust the instrument 2 Perform the following steps to adjust the SDI Jitter application a b Touch the Jitter soft key Connect a 67 5 MHz clock to the VM700T SDI Ch A input Terminate the SDI Ch A loopthrough using a 75 2 high frequency terminator Touch the Calibrate soft key Touch the Proceed soft key once to perform the Jitter Scale Factors adjustment Wait until the message at the bottom of the screen disappears Touch the Proceed soft key a second time to perform the Jitter Offset adjustment Check that the displayed New Data values are within the limits shown in Table 5 6 If the displayed values are within the required limits touch the Accept Data soft key Remove the signal cable from the SDI Ch A input Table 5 6 Jitter application adjustment value limits Measurement New data value limits J itter scale factors Timing 0 650 to 0 800 Align 0 700 to 0 860 Frame 36 000 to 48 000 Line 72 000 to 97 000 J itter offs ets Timing 0 040 to 0 120 Align 0 020 to 0 080 Frame 84 000 to 152 000 Line 84 000 to 152 000 VM700T Video Measurement Set Service Manual Adjustment Procedure
338. stream of all zeroes Hence the third test checks for bits that are not zero Since this indicates a spurious data movement condition Each such bitis annunciated via a message on the console VM700T Video Measurement Set Service Manual 6 109 Troubleshooting Procedures Table 6 13 SDI Option 1S diagnostic test descriptions Cont Test name 2C and EDH Chips Description The I2C chip is a Philips PCF8584 device that provides a 2 wire interface by which ICs can communicate with each other The CPU in the VM700T uses this device to communicate with the Gennum GS9001 Error Detection and Handling Coprocessor EDH chip The I2C interface is tested first and if it works then itis used to do a limited amount of communication with the EDH chip PCF8584 Rd Wrt There is only one register in the I2C chip 059 which can be both read and written all others are read only or write only This register is tested by writing and reading back a series of test patterns If there is a mismatch a message is generated to the console to indicate the expected and actual values that were read back from the chip EDH Chip If the previous test passes then this testis run else itis set to N A Since the interface to the EDH chip U41 is a 2 wire serial interface the only point of the test is to exchange some data with the device to see if it can be written and read Consequently we write and read back the TV standard bits in the EDH chip using the I
339. strument High quality cables have a reliable continuous outer shield braid and foil that has low impedance connections to shielded connector housings at both ends 2 Peak Inrush Current 35 5 A 230 VAC 50 Hz VM700T with Power Line Conditioner accessory used on 230 Vac power mains VM700T Video Measurement Set Service Manual Specification Table 1 8 Safety standards Category Description 0 5 Nationally Recognized Testing UL3111 1 Standard for Electrical and Electronic Measuring and Testing Equipment Laboratory Listing Canadian Certification CAN CSA C22 2 No 1010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use European Declaration of Conformity Compliance was demonstrated to the following specification as listed in the Official Journal of European Communities Low Voltage Directive 73 23 EEC amended by 93 68 EE C EN61010 1 A2 1995 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use Additional Compliance ANSI ISA S82 02 01 Safety Standard for Electrical and Electronic Test Measuring Controlling and Related Equipment 1994 IEC1010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use Table 1 9 Safety certification compliance Category Description Temperature operating 45 C to 4509 C Altitude maximum operating 2000 Meters Relative Humidity maximum operating 80 for tempe
340. t Chrominance Amplitude Chrominance Phase Chrominance to Luminance Intermodula tion Table 1 54 ColorBar Measurement Luminance Level Absolute mode accuracy Relative mode accuracy 0 to 100 1 0 0 5 0 to 360 0 2 Absolute mode accuracy Relative mode accuracy 0 to 100 IRE 30 5 IRE 0 2 0 to 714 3 mV Chrominance Level excluding gray and 0 to 100 IRE 1 0 of nominal see 10 296 black 0 to 714 3 mV Table 1 55 Chrominance Phase 180 of nominal 0 5 of nominal 50 19 1 20 VM700T Video Measurement Set Service Manual Specification Table 1 55 SMPTE color bar nominal values Color Prase degrees lo ua zm 234 ree TE 1034 Blue 108 1 444 2 347 1 Table 1 56 Differential Gain and Phase Measurement Differential Gain Absolute mode accuracy Relative mode accuracy 0 to 100 Differential Phase 0 to 360 0 3 0 03 Table 1 57 Frequency Response and Group Delay Measurement Frequency Response Group Delay Table 1 58 Horizontal Blanking Measurement Blanking Start Blanking End Blanking Width Table 1 59 Horizontal Timing Measurement Burst Level Horizontal Sync Rise and Fall Time Horizontal Sync Width Absolute mode accuracy Relative mode accuracy 40 dB 1 0 dB 0 3 dB 45 ns Absolute mode accuracy 0 1 us to 4 2 us 50 ns 6 8 us to 12 2 us 50 ns 6 9 us to 16 4 us 50 ns Range
341. t 10 frequencies over the entire range Tested frequencies should include the specification limits 20 Hz 20 kHz and the 40 Hz breakpoint Example frequencies to test might also include the following 100 Hz 200 Hz 1 kHz 2 kHz 10 kHz 3 Check that the measured frequency is accurate to the limits shown in Table 4 5 for the applied test signal frequency and level and that the phase difference between channels meets the phase difference specification VM700T Video Measurement Set Service Manual 4 23 Audio Option 41 Triple Input Verification Procedure 4 24 VM700T Video Measurement Set Service Manual _ UU SDI Option 1S Performance Verification This section contains the performance verification procedure for Option 15 The test equipment required to perform the Option 1S verification procedures is listed in Table 4 7 Test equipment examples are based on the test equipment that many customers and the Tektronix service centers have installed for supporting the VM700 family of video measurement sets Substitute test equipment meeting the minimum specifications may be used if available If you do not have the required test equipment you can return your instrument to a Tektronix service center to have its performance verified Table 4 7 Test equipment required for Option 1S verification Minimum specification Purpose Example Test equipment Leveled sine wave generator Output source resistance 50 1
342. t Input soft key and then touch the Update amp Exit soft key to exit the configuration file Press the 700 front panel Measure button Touch the SDI soft key and then touch the SDI_EyeDiagram soft key Press the VM700T front panel Menu button Touch the Waveform soft key and then select Full Signal on and Free Run off Check that the readout text in the upper right corner of the display reads 143 Mb NOTE You can set the Eye Diagram horizontal scale units to UI unit intervals or to ns nanoseconds To set the horizontal scale touch the Cursors Units soft key and then touch the Jitter Units soft key Touch the Calibrate soft key only visible if the CPU dip switch S4 is set to Open and then touch the Horz Pos 143 Mbit soft key Turn the front panel knob to center the left zero crossing of the Eye Diagram at approximately 0 15 UI 1 ns on the horizontal scale See Figure 5 13 Touch the Horz Pos 143 Mbit soft key to save the adjustment wait message will appear Replace the 143 Mb signal on the SDI Ch A input with a 525 line 270 Mb 100 color bars signal Check that the readout text in the upper right corner of the display reads 270 Mb Touch the Horz Pos 270 Mbit soft key Turn the front panel knob to center the left zero crossing of the Eye Diagram at approximately 0 15 UI 0 5 ns on the horizontal scale See Figure 5 13 VM700T Video Measurement Set Service Manual Adjustment Procedure
343. t and adjustment resiStoF a obses Lis eee fede eR eR BRON SR EO aS de Figure 5 13 Adjusting the eye crossing horizontal position Figure 5 14 Adjusting the rising edge of the SDI Eye Diagram application Figure 6 1 Locating the major standard assemblies Figure 6 2 Removing acover panel Figure 6 3 Removing the left card cage center support Figure 6 4 Installing the I O board in the card cage Figure 6 5 Locating the audio option boards in the left side card cage Figure 6 6 Orientation of the cable adapter collar Figure 6 7 Option 41 Triple Input Audio input connector pin locations Figure 6 8 Ferrite forms installed on the Option 41 interconnection cable Figure 6 9 Loosening the screws on the right card cage retainer Figure 6 10 Location of right card cage circuit boards Figure 6 11 Acquisition Memory board 18 cables Figure 6 12 SDI board A22 cable connections Figure 6 13 Installing the SDI Rear Panel Interface A23 assembly Figure 6 14 Disconnecting the Analog Input board connectors 4 1 4 3 4 4 4 4 4 16 4 17 4 21 4 22 5 5 5 11 5 12 5 12 5 13 5 13 5 17 5 20 5 20 5 22 5 25 5 27 5 29 5 30 6 7 6 8 6 10
344. t first remove the right side cover and the card cage retainer The following procedures explain how to remove the GPIB board Required Tools Use the following tools to remove the Option 48 circuit board m Flat blade screwdriver 3 16 blade Pozidrive screwdriver 1X VM700T Video Measurement Set Service Manual Maintenance Procedure Use the following procedure to remove and replace the Option 48 GPIB Interface board 1 Perform the following steps to remove the GPIB Interface board a Remove the left side cover panel refer to Cover Panel Removal and Replacement on page 6 8 Remove the retaining screw from the card cage center support and remove the center support from the card cage see Figure 6 3 on page 6 10 Remove the circuit board retaining screw from the GPIB circuit board NOTE It may also be necessary to remove or loosen the circuit board retaining screw immediately above the one retaining the circuit board you are removing d Unplug the board using the ejector tab and remove the board from the card cage 2 Perform the following steps to replace the GPIB Interface board a Guide the board onto the card cage track and slide it into the card cage connector see Figure 6 4 Align the circuit board connector pins with the main interconnection board connector and press firmly to seat the connector Replace the circuit board retaining screw Replace the circuit board
345. t panel knob to position the cursor to 400 mV as read in the readout 6 Touch the Volt Cursor 2 soft key and then use the front panel knob to position the cursor to 400 mV as read in the readout 7 Adjust the amplitude of the leveled sine wave so that the displayed waveform amplitude matches the voltage cursors NOTE It may be necessary to expand the waveform to accurately position the voltage cursors You can expand the waveform by touching the waveform and then using the front panel knob to adjust the waveform display If there is a small DC offset adjust for equal error at the two cursors so that waveform amplitude is 600 mV 8 Setthe frequency of the leveled sine wave to 550 MHz without adjusting the signal amplitude 9 Touch the Volt Cursor 1 soft key and then use the front panel knob to position the cursor to the top of the sine wave 10 Touch the Volt Cursor 2 soft key and then use the front panel knob to position the cursor to the bottom of the sine wave 11 Check that the waveform amplitude readout V 1 V2 is 520 mV to 721 mV 65 to 90 VM700T Video Measurement Set Service Manual 4 29 SDI Option 1 Verification Jitter Application The following Jitter application checks verify the frequency response of the Timing Jitter and Alignment Jitter measurements They also verify the Jitter Waveform and Jitter Spectrum displays including the 10 Hz and 1 kHz filters in both Line and
346. t rebuilding the entire list NOTE The custom list you build is not retained when exiting this menu VM700T Video Measurement Set Service Manual 6 63 Troubleshooting Procedures 6 64 Diagnostic Help Menu One of the menu choices in the VM700T START UP MENU is the diagnostic help menu The help menu has two choices List special instrument power up modes and List diagnostic front panel button uses Figure 6 38 lists the front panel buttons that can be used directly to make menu selections These keystrokes are in lieu of highlighting the menu choice and pressing the Select button when one of the listed key choices is available in a menu Low Level Diagnostic Interface DIAGNOSTIC FRONT PANEL BUTTON USES Some Front Panel buttons may be used in place of moving the hilight cursor and pressing the Select button Below are some common diagnostic menu selections and their Front Panel button equivalents Display Next Menu Page Arrows Key FR PNL BUTTON SPC Pause Freeze RET Continue Display Abort Auto Reprint Menu Select All A Un Sel All C Previous Menu Page Move Expand Press Any Key to Continue Figure 6 38 Front Panel diagnostic selection buttons Backdoor Boot Modes The other choice in the diagnostic help menu provides a list of the special power up modes that are accessible through pre
347. t replaced to effect a repair If there is a common hardware component or components tested in the different failures suspect the module that has the common components NOTE The interdependencies between modules is very high Several modules may have to be swapped into the instrument to determine the exact module that is causing a diagnostic failure Table 6 5 is then used to determine the modules that are most probable to be the source of the failure 6 82 VM700T Video Measurement Set Service Manual Troubleshooting Procedures Table 6 5 Diagnostic test number to hardware components tested cross reference Test no 1 Status Checks Checks 2 EI or PAL VCO Lock 3 Control Registers 4 Overrange Detector 2 5 Clock Detector X 2 6 Clamp Counters A C and Acq Sig Counters 5100 5102 7 eere 8 State Machine Settings Trigger and Sequence RAM 9 RAM 10 FIFO 11 Load Looping n owe B pee _ x x 5 smeowm ESI SN 16 ode Checks X X X X X X X X X X 17 Bit Patterns X X X X X X X X X X 18 DVM X X X umm p p RETE E n wem 00 x X p T RET P d 2 gem Eu 23 Input Selection X 24 i gt gt gt X gt gt gt gt for each channel 25 Clamp for each X i i i i channel 26 Times
348. t states This DSACK generator is much faster than the DSACK generator in the interrupt controller VM700T Video Measurement Set Service Manual Theory of Operation Front Panel Board 10 1 The front panel board decodes input from the control knob and touch screen and relays push button and LED information to and from the A10A2 keypad board The front panel board connector to the display memory board contains most of the lines of the 68008 bus including lines for relaying push button and LED information to and from the keypad board Additional lines for power and the signals INTEGRATE and CLK200 are provided Figure 3 10 shows a block diagram for the front panel board To F rom ADDRESS STATUS CONFIGURATION HK DIGITAL CPU Board DECODER PORT REGISTER KNOB To F rom Keyboard De AUTONULL l OVERFLOW DETECTOR INVERTER SYNCHRONOUS AID DEMODULATOR INTEGRATOR CONVERTOR e CLK200 To From MULTIPLEXER Touch Panel Figure 3 10 Front panel board block diagram VM700T Video Measurement Set Service Manual 3 27 Theory of Operation Keypad Board 10 2 Control Knob Push Buttons LEDs 3 28 The VM 700T front panel push buttons LED and the control knob are connected to the keypad board The keypad board is connected to the front panel board through a flex cable that carries power the 68008 data bus enable signals from the front panel board s address
349. t way to start the measurement set for normal operation is to turn off the VM700T and turn it back on again VM700T Video Measurement Set Service Manual 2 7 Operating Information Low Level Diagnostic Interface knob moves cursor Select Line inputs selection SET DIAGNOSTICS POWERUP MODE Select a Powerup Mode from the list below The mode selected will be stored in Diag NVRAM and will be effective for NORMAL powerups ie Boot Switches in NORMAL position The current Powerup Mode setting is STARTUP MENU Key Selection Q iss QUICK START eee reu Skip Diagnostics start Instrument M vus STARTUP MENU uerit sun Goto VM700T Startup Menu POWERUP DIAGS Do Diagnostics start Instrument L LOW LEVEL DIAGS LOOP Loop on Low Level Diagnostics D HIGH LEVEL DEBUG Run Instrument in DEBUG MODE Reprint 8 Abort Menu Input your selection Figure 2 7 Set diagnostics power up mode menu Measurement Set Operating Modes 2 8 Waveform Mode Vector Mode The measurement set has multiple operating modes These modes provide different measurements and different means of making measurement The following information explains each of the operating modes For detailed waveform analysis you can display the actual signal and take additional measurements manually In Waveform mode cursors are available to aid in measuring time frequency and amplitude
350. tainer This section describes removing and replacing the VM 700T components responsible for instrument display and user interface These components include the CRT assembly the touch panel and the keypad board assembly Removing and replacing these components requires first removing the instrument cover panels the CRT bezel and to remove the keypad board assembly the right side card cage retainer Required Tools Use the following tools to remove the display and control components m Flat blade screwdriver 3 6 or inch blade Combination wrench or nut driver 3 16 inch Pozidriv screwdriver 2X CRT Bezel Use the following procedure to remove and replace the CRT bezel 1 Perform the following steps to remove CRT bezel a Remove the instrument cover panels refer to Cover Panel Removal and Replacement on page 6 8 b Remove the four screws holding the bezel to the front frame see Figure 6 19 There is one screw on each side and one each in the top and bottom of the bezel c Carefully separate the bezel from the frame and disconnect the 5 conductor cable from the STBY ON switch d Remove the nut that holds the STBY ON switch ground strap ring terminal to the keyboard bracket and disconnect the ground strap see Figure 6 20 2 Replace the CRT bezel by performing step 1 in reverse order NOTE Use care in tightening the bezel retaining screws The threaded bezel inserts can be stripped from the
351. tandard and release version This information is used by the d T S fi C iagnostic to determine valid filter ID for each slot he frequency response sub test generates a psuedo square wave ignal by switching channel input between A and B with each channel input clamped to a different DC level The signal is routed through the ter slot under testto the ADC acquired and analyzed Discrepan ies are displayed on screen When an empty slot is correctly identified this test displays NA 1 Each gating pattern has a different number of active video lines so the ratio of the NTSC pattern cal factor to always on pattern equals the ratio of the NTSC pattern active lines to the always on pattern number The same is true for PAL Range is the arithmetic sum of the measured bit weights and bit weights are measured as the effect of toggling only the Table 6 5 provides a cross reference between the test numbers and test names given in Table 6 4 with the hardware components tested An X in the Test no row indicates that the hardware component given in the column head is required to be operational for the test to pass See Figure 6 55 for the hardware compo nent reference If one or more diagnostic tests fail note the hardware compo nents tested They can be located on different modules so the task is to determine which hardware component is causing the failure to occur That will isolate the problem to a specific module that mus
352. ted on the GPIB board You can see them at the rear of the measurement set as shown in Figure 2 15 Use Table 2 2 to determine what a lighted lamp means and its color Table 2 2 Status indicators Label Color Meaning when lighted LSTN Green Addressed to listen MLA when on TALK Green Addressed to talk MTA when on The LED is always on in talk only mode SRQ Yellow Service request SRQ pending when on REM Yellow Remote control active when on LOCK Red FrontPanel lockout CACT Green Controller active state when on SCTL Green System control never on Figure 2 15 GPIB board rear panel 2 21 Operating Information SDI Option 1S Rear Panel Connections Figure 2 16 shows the VM700T rear panel with Option 15 installed Figure 2 17 shows a close up of the Option 15 rear panel 2 22 The Option 15 rear panel connectors provide the following functions The SDI Ch A input is a noninterfering loopthrough BNC input for serial digital video signals You must use the SDI Ch A input to perform electrical signal measurements in the following applications SDI Eye Diagram SDI Jitter and SDI Wander The remaining loopthrough connector must be precision terminated in 75 2 when not used in a loopthrough mode The primary function intended for this input is to measure a signal under test The SDI Ch B input is an internally precision terminated 75 2 BNC input for serial digital video
353. ter The VCOs are located in metal housings on the Genlock board near the back of the Display Monitor CRT see Figure 5 1 NOTE If your instrument is a dual standard instrument check both VCOs before continuing with step 9 10 11 12 13 Disconnect from the VM700T and reinstall the instrument covers Disconnect all signal inputs from the VM700T then wait 5 minutes while the internal temperature of the instrument stabilizes Press the Measure hard key and touch the Video soft key if necessary to recall the Video measurement menu Touch the Burst Frequency soft key With no signal applied the VM700T displays a warning message that tells you to check the signal source because a signal cannot be found The burst frequency measurement starts automati cally after 3 seconds the Loss of Sync indicator blinks Press the Menu hard key and touch the Reference soft key in the menu display VM700T Video Measurement Set Service Manual Adjustment Procedure CHAN CHAN CHAN
354. ter is to be loaded with the 16 data bits or is to hold the current count When the counter overflows the CARRY bit is returned to the address register The CARRY bit can be used to count samples lines frames or whatever the application needs to count Dynamic Address Latch The 11 bits received by this address latch are clocked through to the dynamic settings static RAM These are the same 11 address bits that are returned to the address register from the output of the sequencer static RAM but delayed one clock cycle Control Word Latch The control word latch holds a three bit control word issued to the data acquisition section of the board These control bits cause the program counter in the data acquisition section of the board to jump to preset addresses Dynamic Settings This circuitry sends additional front end control data to the Analog Input Genlock and Filter Switch boards The key requirement for this block is that its outputs must be able to change rapidly because offset gain dither input selection and filter selection may change many times during a single line of video The dynamic settings static RAM can be accessed by the CPU microprocessor anytime even during an acquisition The same control bit SRUN that disables the sequencer static RAM determines if the microprocessor access requires synchronization Six of the eight bits sent to the dither generator are used as data the other two are for control The dither ge
355. terrupted when you access one of the following applications SDI Eye Diagram SDI Jitter and SDI Wander The AES EBU Digital Audio input is used to measure external digital audio signals This BNC input is internally terminated in 75 The LTC Time Code input is a standard Longitudinal Time Code interface input used for time stamping measurement log reports VM700T Video Measurement Set Service Manual Operating Information Option 19 rear panel Fan exhaust 060 Power Fuse ON OFF Line voltage VGA Parallel Alarm RS 232 connector switch selector output printer port connector ports Figure 2 16 VM700T rear panel with Option 1S installed Figure 2 17 Option 1S rear panel VM700T Video Measurement Set Service Manual 2 23 Operating Information 2 24 VM700T Video Measurement Set Service Manual of Operation This section describes the electrical operation of the VM700T Video Measure ment Set using the major circuit blocks as modules This section has two main parts m Overview of the VM 700T System describes the system operation of the modules circuit boards m Module Functional Description describes circuit operation of the modules from a functional circuit block perspective Block diagram illustrations accompany the appropriate text Overview of The VM700T System The video signal enters the VM 700T ana
356. th 3 meters gt Figure 5 11 Cable requirements for adjusting the Cable Meter VM700T Video Measurement Set Service Manual 5 25 Adjustment Procedure Touch the Calibrate soft key and then touch the Proceed soft key Set the cable clone for 100 m of cable or replace the standard length cable on the SDI Ch A input with 100 m of cable Touch the Proceed soft key Replace the 143 Mb signal with a 525 line 270 Mb 100 color bars signal Leave the SDI Ch A input terminated Set the cable clone for 0 m of cable or replace the 100 m of cable with the standard length cable Touch the Proceed soft key Set the cable clone for 100 m of cable or replace the standard length cable on the SDI Ch A input with 100 m of cable Touch the Proceed soft key Replace the 270 Mb signal with a 525 line 360 Mb television signal Leave the SDI Ch A input terminated Set the cable clone for 0 m of cable or replace the 100 m of cable with the standard length cable Touch the Proceed soft key Set the cable clone for 100 m of cable or replace the standard length cable on the SDI Ch A input with 100 m of cable Touch the Proceed soft key Check that the Cable New Data is within the limits shown in Table 5 7 If the data is within the limits touch the Accept Data soft key Touch the Update All soft key and then touch the Really Update soft key Replace the cable clone or the 100 m of cable with the standard le
357. the baseband composite video signal but leaves the horizontal and vertical sync information The sync stripper provides this information on its horizontal sync and composite sync combined horizontal and vertical sync outputs Video signals from VCRs sometimes contain only rudimentary vertical sync information which can cause the sync stripper to mis trigger A 200 microse cond delay allows the sync stripper to function properly in the presence of this kind of vertical sync Some countries place digital audio on the horizontal sync pulse using sound in sync SIS A menu selection in the waveform application engages circuitry in the sync stripper to sustain good performance in the presence of SIS A temperature compensated crystal oscillator provides a 20 25 MHz clock with 5 parts per million ppm accuracy It is divided to either an NTSC or PAL line rate frequency and used as one of the selections for the phase locked loop reference clock It is also used as the sampling strobe in 20 25 MHz sampling mode VM700T Video Measurement Set Service Manual 3 7 Theory of Operation ain Mode Frame Mode Sound In Frame Ref Clock approx 2 3 MHz Composite sync Frame On Off mode control On Off grsc VCO H Phase Locked Loop ni RTO RTI C ram Video Composite Sync orrection Sync Horizontal Sync Lo
358. the Update amp Exit soft key to write out save any changes to the file press the No change amp Exit soft key to leave the file as it was when it was last saved High Level Diagnostics Test Figure 6 55 illustrates the diagnostic test blocks of the high level diagnostics to assist you in determining the module interdependen cies for the successful completion of the tests Table 6 4 lists and describes the VM700T high level diagnostic tests Additional diagnostics are added to this list with the addition of the hardware options GPIB Interface Audio Measurements and Serial Digital Interface 1 TheAudioProcessor Diagnostic and AudioAnalog Diagnostic selections are available only with the VM700T Audio option GPIB Diagnostics is added to this list when the GPIB option is installed 6 78 VM700T Video Measurement Set Service Manual Troupleshooting Procedures A1 Analog Input CAL DAC 4 Filter Switch Acquisition id Bias O d ang Acquisition Data Path Clamping Input Select Acquisition Data Data Path 1x 8x Path 1 A Acquisition Data P ath Dynamics Control Dynamics Control gt Gain A4a 8 bit Offset 5 bit Gain 6 bit Dither Acquisition Data Path Dynamics Control A2 Genlock Access Dynamics RAM z Genlock A18a NTSC VCO Acquisition Data Path Contro
359. the same interface You can also send hard copy output to a parallel printer through the Centronics compatible parallel printer port The measurement set can be operated from a remote terminal through either of the RS 232C ports to monitor unattended transmission systems or to put systems under computer control The output connector on the rear panel provides a copy of the measurement set display for remote viewing on a standard VGA monitor A GPIB port is added for remote control or hard copy output to a GPIB printer with Option 48 installed VM700T Video Measurement Set Service Manual Operating Information Front Panel Controls The front panel controls shown in Figure 2 8 consists of a touch screen interface and a 20 button keypad with a control knob VM700T VesSusevenr turbo Waveform Vector Picture Measure Auto Ta pec 0o EJ G G 1 SOURCE Freeze Average Menu Help Configure Function Copy EJ dep dep dep dal Select Line O Move O Expand o 0 0 40 0 50 0 60 0 Noise reduction RESET MicroSeconds APL 49 9 Precision Mode off 525 line NTSC No Filtering Synchronous Sync Source Slow clamp to 0 00 V at 6 63 us Frames selected 1 2 Cursors Noise Extra Filter Clamp I Display 15 05 rFunctions select Couple Display Graticule PISFAIL OVER TEMP Intensity 1
360. ther and genlock VM700T Video Measurement Set Service Manual 3 1 Theory of Operation The CPU board A5 contains a microprocessor a floating point unit real time clock Flash EPROM NVRAM display memory and display driver hardware The display driver hardware converts acquired data to video and drives the VM700T display A monochrome output to the rear panel is also derived from the display driver hardware The Flash EPROM stores application programs and the NVRAM stores system and configuration files created by the user The front panel interface hardware is also on the CPU board This interface controls the touch panel control knob and keyboard interfaces to the CPU microprocessor The audio option boards for Option 40 and 41 provide the interface for audio test signals into the VM 700T Operation of the audio option measurements are discussed in VM 700T Option 40 41 42 Audio Measurements User manual A second option requiring additional hardware is Option 48 the GPIB option This option provides a interface for remote control in a GPIB controlled system Operation of the GPIB option is described in the VM 700T GPIB Interface Option 48 Programmer manual VM700T Video Measurement Set Service Manual Theory of Operation Module Functional Description This part describes the operation of each circuit board module in the VM 700T Block diagrams accompanying the text show the functions of the modules Analog Input
361. tics Table 1 14 Power Line Conditioner Environmental Characteristics Table I 15 BarLane 222220222229 RR eee eb eG RE Verr S Table 1 16 Bowne ee RC UR MEET 6 85 6 86 6 86 6 87 6 90 6 91 6 93 6 95 6 96 6 102 6 105 6 105 9 3 9 4 10 17 10 19 10 21 10 23 10 25 10 27 1 1 1 2 1 2 1 3 1 3 VM700T Video Measurement Set Service Manual Table of Contents Table 1 17 Burst Frequency Table 1 18 Chrominance to Luminance Table 1 19 Chrominance Noise Table 1 20 Chrominance Nonlinearity Table 1 21 ColourBar Table 1 22 Differential Gain and Phase Table 1 23 Frequency Response and Group Delay Table 1 24 Horizontal Blanking Table 1 25 Horizontal Timing Table 1 26 Incidental Carrier Phase Modulation Table 1 27 Jitter 220 e eror R REESE Table 1 28 K Factor Table 1 29 Level Meter Table 1 30 Line Frequency Table 1 31 Luminance Nonlinearity Table 1 32 MultiBurst Table 1 33 Noise Spectrum Table 1 34 SCH Phase Table 1 35 TwoField Table 1 36 Vertical Blanking Table 1 37 VITS ID Table 1 38 Line Blanking timing measurements
362. ting the Touch Screen 2 4 Benchtop Mounting standalone VM700T benchtop for portable use apply the four adhesive rubber feet provided with the accessory to the bottom of the box at the corners Place the conditioner box in a convenient location where you can make the power cord connections Power Cord Connections Connect the Power Line Conditioner in the power line between the AC mains and the VM700T power input connector in the following order 1 Plug the output power cord connected to the box into the AC power input connector of the VM700T 2 Plug the AC mains power cord into the AC input connector of the power line conditioner box 3 Plug the AC mains power cord into the 230 Vac mains source The measurement set as shipped from the factory is configured to skip diagnostics at power on for a quicker start up You can run diagnostics at power on by doing an Auto Reset Refer to Auto Reset on page 6 84 for information on forcing an Auto Reset If any of the diagnostic tests fail refer your measurement set to a qualified service person You may want to access the diagnostics for a couple of operating selections These are setting the power on run mode either to run the diagnostics at power on or to skip them for a quick start and calibrating the touch screen The measurement set is shipped from the factory with its touch screen fully calibrated However if you notice misregistration of the touch scre
363. ting the V bit itself Channel Selection MUX The channel selection MUX selects between the two SDI channels EDH Coprocessor The EDH coprocessor detects and decodes EDH errors The coprocessor also participates in the automatic rate detection function VM700T Video Measurement Set Service Manual Theory of Operation Analog Signal Path Digital Signal Path Rear Panel SDI SDI SDI AES EBU Analog LTC ChA 1 Output Digital Audio Ref Time Code 1 mm AES Audio mm receiver 1 Clock Clock recovery recovery Analog sync stripper Analog line amp frame synthesizer Channel select Eye J itter select Deserializer Deserializer Line amp frame Line amp frame ynthesizer synthesizer itter waveform Wander Analog frequency peak counter detectors E Diagram ise fall flags Channel select mux DH coprocessor Digital Analog mux Audio data serial Eye rising falling 2 bits ChA line amp frarre ChB line amp frarre Eye sweep start ChATRS error Ch B TBS error Audio left chanel Analog line amp frarre LTC change gt Bus Functions contained in data path mux IC Audio Video Deserializer Functions contained in mux Flag
364. tion 15 installed Maximum operating temperature 1 42 VM700T Video Measurement Set Service Manual EES SS Operating Information The VM700T Video Measurement Set is a multi function television test and measurement device with an easy to use interface The measurement set performs the functions of a waveform monitor vectorscope automatic measurement set and a noise measurement set on acquired television signals The measurement set does measurements on video signals obtained from either live TV signals broadcast or cable or television test equipment You can select numeric value displays to confirm signal path quality or graphic displays for more detailed analysis of the applied signal The measurement set can be operated directly using the front panel or remotely using one of the RS 232C ports on the rear panel Installation The measurement set comes standard as a rack mounted unit Refer to the VM700T Rack Mounting Instructions on page 6 44 for the rack mounting installation instructions The following unpacking and power requirements information is repeated there The measurement set may also be ordered as a cabinetized unit Unpackaging When you unpackage the measurement set keep the shipping carton and packaging material If you need to return the measurement set for servicing you will then have packaging available that provides adequate protection for shipment Power Requirements The VM700T Video Measurement Set ope
365. tion 1S functions You cannot access any Option 1S functions if the VM700T is set to Mode Analog 2 Verify that all Option 1S and VM700T diagnostics pass refer to SDI Option Diagnostics on page 6 104 3 Inspect the rear panel connectors for damage 4 Inspect the internal cable connections between the SDI Rear Panel Interface assembly and the SDI board and the cable between the SDI board and the Acquisition Controller board The instructions for isolating the SDI option faults listed below are found on the following pages M No signal from the SDI Ch A input m No signal from the SDI Ch B input m No signal from the Analog Ref input M No signal from the AES EBU Digital Audio input m No signal from LTC Time Code input m No signal from the SDI Output connector Perform the following steps when the VM700T will not display a known signal on the SDI Ch A input 1 Connect a digital video signal to the SDI Ch A input and terminate the loopthrough connector 2 Setthe VM700T to display the channel A signal using the SDI Waveform application VM700T Video Measurement Set Service Manual Troubleshooting Procedures NOTE The VM700T must be set to Mode Digital The Source Selection Digital configuration file must be set Auto Detect or for the bit rate and standard of the digital test signal 3 Check for a Loss of Signal message on the display 4 If hardware trouble is indicated other than the Lo
366. tion 41 audio input 1 2 3 for a video source A B C and then select an appropriate audio source file if you want to use an audio source file other than the system default In the next steps you want to have source to audio input 1 source B to 2 and source C to 3 To specify audio inputs and audio source files for video sources use the following procedure 1 A wu ROO From Measure Mode press the Configure front panel button touch the Configure Files soft key followed by the Source_Selection Audio soft key Rotate the front panel knob to highlight the source A B C for which you are specifying an audio input and an audio source file Touch the highlighted audio input 1 2 or 3 to select it Rotate the front panel knob to change the audio input selection Touch the highlighted source file to select it Rotate the front panel knob to change the audio source file selection if you are using an audio source file other than the system default When you have specified the audio inputs and source files touch the Accept Input soft key If the change is correct touch the Update amp Exit soft key otherwise touch the No Change amp Exit soft key VM700T Video Measurement Set Service Manual 4 19 Audio Option 41 Triple Input Verification Procedure NOTE If you change audio input and source files and then decide to exit the directory and cancel the change you must press the Accept Input soft key follo
367. tion 42 Specifications Automatic Audio Test Specifications Table 1 85 0 33 Automatic audio test measurement specifications The following tables give the specifications for the audio measurements Measurement Range Accuracy includes flatness Insertion Gain Error 6 dB 50 2 dB Sweep Gain Min and Max 12 dB 0 1 dB THD N at 1020 Hz lt 0 0396 to 70 10 1 digit 2nd Harmonic at 60 Hz lt 0 03 to 70 10 1 digit 3rd Harmonic at 60 Hz lt 0 0396 to 70 10 1 digit Crosstalk into channel 3 1dB Test Level 6 dBu lt 66 dB to 0 dB 0 dBu lt 60 dB to 0 dB 6 dBu lt 54 dB to 0 dB SNR unweighted 4 1 dB Test Level 6 dBu 10 dB to gt 76 dB 0 dBu 10 dB to gt 70 dB 6 dBu 10 dB to gt 64 dB SNR weighted 45 2 dB Test Level 6 dBu 10 dB to gt 76 dB 0 dBu 10 dB to gt 70 dB 6 dBu 10 dB to gt 64 dB Max Compandor Error rise fall 6 dB 0 2 dB Gain Difference 12 dB 0 2 dB Phase Difference 180 to 180 19 1 Assumes insertion gain is within 6 dB 2 measurement range specification assumes that the input level is within 6 dB of the 0 33 test level in the audio configuration The actual O 33 test level range is 6 dBu to 14 dBu 3 The value for other test levels can be calculated from the formula 60 Test Level Measured with Quasi Peak response as per CCIR 468 4 recommendation The measurement range can be determined from the formula 70 Test Level
368. to 714 mV or with less rounding to 714 3 mV A 1 V pk pk signal is 140 IRE Measure Mode Table 1 47 Bar Line Time Measurement Range Absolute mode accuracy Relative mode accuracy Bar Level 50 IRE to 200 IRE 30 5 0 2 Sync Level 20 IRE to 80 IRE 0 5 50296 Sync to Bar Top IRE to 280 IRE 0 5 0 2 Sync Bar Ratio 10 to 125 0 5 0 2 100 nominal Bar Tilt Rec 569 0 to 20 0 1 Line Time Distortion Rec 567 0 to 20 0 1 Bar Width 10 us to 30 hs NA Table 1 48 Bounce Measurement Range Accuracy Peak Deviation 0 to 5096 1 Settling Time 0 to 10 sec 100 msec VM700T Video Measurement Set Service Manual 1 19 Specification Table 1 49 Burst Frequency Measurement Burst Frequency Error 100 Hz 0 5 Hz Table 1 50 Chrominance to Luminance Gain and Delay Measurement Absolute mode accuracy Relative mode accuracy Chrominance to Luminance Delay 300 ns 5 ns 1 0 ns Chrominance to Luminance Gain Ratio 0 to 160 1 0 0 1 Table 1 51 Chrominance Frequency Response Measurement Range Absolute mode accuracy Relative mode accuracy Reference Amplitude 0 to 100 IRE 1 0 5 Frequency Response 0 to 100 IRE 1 0 5 Table 1 52 Chrominance Noise Measurement AM Noise PM Noise Range Absolute mode accuracy 1 dB 20 dB to 60 dB 1 dB 20 dB to 60 dB 20 dB to 80 dB 20 dB to 70 dB Table 1 53 Chrominance Non Linearity Measuremen
369. to the VM 700T to determine exactly how it should be connected Table 6 8 gives the null modem cable configurations for 9 pin to 9 pin and 9 pin to 25 pin DTE connectors that should work in most cases for remote control and for viewing the output of the VM 700T in debug mode The pin numbers listed for the Terminal DTE are the most common locations for the corresponding signals Table 6 8 Typical RS 232C null modem cable wiring 700 DTE to terminal with 25 pin DTE connector VM700T DTE to terminal with 9 pin DTE connector VM700T pin no Terminal pin no VM700T pin no Terminal pin no 1 DCD 4 DTR 1 DTR 20 DTR 2 RD TD 2 RD 2 TD 3 TD 2 RD 3 TD 3 RD 4 DTR 1 DCD 4 DTR 6 DSR amp 8 DCD 5 Signal Ground 5 Signal Ground pee Ground 7 Signal Ground 6 Unused 6 DSR 6 Unused 20 DTR 7 RTS 5 CTS 8 5 8 4 RTS 9 Unused RI Unused RI 9 1 Unused FG 1 Both ends of a DTE to DTE cable are usually female DB 25 connectors VM700T Video Measurement Set Service Manual 6 89 Troubleshooting Procedures Troubleshooting the Power Supply and CRT Display 6 90 A Power Supply This section contains information on how to troubleshoot the power supply module and the CRT display WARNING High voltages present inside the VM700T chassis can cause serious injury All service procedures that require remo
370. to the serial ports NOTE Diagnostics can also be controlled and executed remotely through the serial port This method is most useful if the display system is inoperative or in a service environment for programmed troubleshooting of the VM 700T Refer to Viewing Diagnostics Remotely on page 6 95 for more information VM700T Video Measurement Set Service Manual 6 55 Troubleshooting Procedures 6 56 During execution diagnostics give positive feedback of progress indicating results as they are gathered During power up execution these results are presented in minimal fashion a test which passes shows only its main result whereas one that fails also shows the sub results that caused the failure During looping and user interactive modes results display options are available to either show only the main test results or all the test results To facilitate quick appraisal of diagnostics results the information is presented in a uniform format Each line consist of fields arranged under a heading shown at the top of the instrument terminal screen The heading line looks something like the following Test measmt unit min max result A brief description of the content of each field follows Field Description Test In a main result the name of the test In a sub result noted by an indentation from the associated main result a description of what was evaluated to determine the main result measmt A measured value pr
371. tored in step 4 Change the TV standard parameter to PAL by pressing the XY Arrow hardkey Change the leveled sine wave generator frequency to 4 43 MHz do not change the output level To speed up the response to the frequency change toggle the Average hardkey off then back on again after the display has re stabilized Check that the amplitude is within 0 5 of the reference level stored in step 4 Repeats steps 1 through 7 for channel B and channel C VM700T Video Measurement Set Service Manual 4 9 Performance Verification 4 10 Measuring the Burst Frequency 26 Disconnect the test equipment from the measurement set NOTE If the response on channel A is out of limits go to Adjusting Filter Flatness on page 5 6 in the Adjustment Procedure section of this manual If either channel B or channel C does not pass but channel A does the Analog input board may need replacement Check with your nearest Tektronix represen tative or factory service for assistance and board replacement information This procedure checks the calibration of the internal oscillator using a signal source of known frequency NOTE To successfully run this procedure the internal oscillator of the measure ment set must be completely stable Power on the measurement set at least 20 minutes before performing this procedure Test Equipment Required m Television signal generator with full field and burst capability accurate to 1
372. tput signal from the VGA connector If that display is normal but there is no display on the CRT check the display monitor In Debug mode the VM 700T redirects the low level diagnostics display data to the rear panel PORT 0 serial connector To view the diagnostics you must connect a terminal or PC to PORT If you connect a PC you must also run a terminal emulator program on the PC to read the output from the VM 700T In Figure 6 57 the Boot switch is shown in the setting that enables output to the serial I O port 0 That is with all switches set to the CLOSED position pushed in at top except S6 The password feature is also enabled by this switch setting but if the password file is empty a password is not needed to make file changes VM700T Video Measurement Set Service Manual 6 85 Troubleshooting Procedures 6 86 S1 55 53 54 55 56 57 58 Closed Q Figure 6 57 Boot switch setting to enable diagnostic output to serial port 0 Setting the Console Baud Rate The baud rate setting for output of the diagnostics through the serial port must be set to match the requirements of the terminal or terminal emulation program used to monitor the output Setting the diagnostic baud rate is done in one of the choices in the Diagnostics Configuration Menu shown in Figure 6 58 Select Set Low Level Diagnostics Baud Rate and press the Select
373. trol register 0 to 0 When this is done bits 3 2 and lt 8 7 gt are used to select the manual rate desired 143 177 270 or 360 MHz These values are then reflected back in the status register in bits 4 3 and 9 8 respectively This factis used to do a loop back test between control register 0 and the status register If the bits match the test passes Ch A Manual Rate Channel A is commanded to lock to each of 4 frequencies on the input 143 177 270 and 360 MHz and the frequency to which the channel locks is displayed If the front end logic detects the absence of a signal then this test is flagged as N A Ch A Auto Rate If there is no signal this is flagged N A Otherwise the SDI board is placed in autorate mode and after a waiting period the status register is checked to see which frequency the circuit locks to This frequency is displayed Ch A Rate Xcheck If there is no signal this is flagged N A Otherwise the manually determined frequency is compared with the frequency detected in autorate mode If there is a difference the test fails Ch B Manual Rate Repeat of the checks run for channel A Ch B Auto Rate Ch B Rate Xcheck A D Converter This group checks the calibration DAC the voltmeter and associated circuits on the board The tests are as follows Voltmeter Inputs The voltmeter 028 has 16 possible inputs feeding itthrough 026 after selection through the analog muxes U25 and U121 Each ofthese
374. tronix field office or representative Changes to Tektronix products are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest improvements Therefore when ordering parts it is important to include the following information in your order B part number instrument type or model number instrument serial number instrument modification number if applicable If you order a part that has been replaced with a different or improved part your local Tektronix field office or representative will contact you concerning any change in part number Using the Replaceable Mechanical Parts List The tabular information in the Replaceable Mechanical Parts List is arranged for quick retrieval Understanding the structure and features of the list will help you find all of the information you need for ordering replacement parts The following table describes the content of each column in the parts list VM700T Video Measurement Set Service Manual 10 1 Replaceable Mechanical Parts Parts list column descriptions 1 Figure amp index number Items in this section are referenced by figure and index numbers to the exploded view illustrations that follow 2 Tektronix part number Use this part number when ordering replacement parts from Tektronix 3and4 Serial number Column three indicates the serial number at which the part was first effective Column four indicates the seria
375. ts harmonic emissions from the VM700T power supply from entering the commercial power mains 7 6 VM700T Video Measurement Set Service Manual Pec A Replaceable Electrical Parts The electrical modules for the VM700T Video Measurement Set are included in the Replaceable Mechanical Parts list Since component level repair is not supported in this instrument individual electrical components are not listed VM700T Video Measurement Set Service Manual 8 1 Replaceable Electrical Parts 8 2 VM700T Video Measurement Set Service Manual EE LL AERE Diagrams The block diagram and interconnection diagram are provided to assist in identifying the interaction between modules in troubleshooting to the module level Use the exploded view diagrams in the Replaceable Parts List section to locate the modules installed in the VM700T Block Diagram Each module in the instrument is assigned an assembly number for example A20 The assembly number appears on the block diagram The overall block diagram is at the board level More detailed block diagrams of the modules are shown in the Theory section with the discussion of the module circuit operation Interconnection Diagram The interconnection diagram shows the connections made between modules to assist in tracing the signal and power distribution routes VM700T Video Measurement Set Service Manual 9 1 Diagrams 9 2 VM700T Video Measurement Set Service Manual SD Ch SD Ch B
376. ttaches to the rack rails The chassis section mounts on the VM 700T is installed at the factory The chassis section slides into the intermediate section which in turn slides into the stationary section Automatic latch 10 32 PHS 10 32 PHS screws screws Chassis section 10 32 5 Screws ae Intermediate oN section J Bar nut Stop latch hole Figure 6 27 Construction of rack slides VM700T Video Measurement Set Service Manual 6 45 Maintenance Mounting the Rack Slides Locate the proper holes in the rack rails as shown in Figure 6 28 Notice that the hole spacing varies with the type of rack When installing the slides in EIA type racks make certain that the slides are attached to the 1 2inch spaced holes Install the stationary section of the rack slides as shown in Figure 6 29 Make sure the stationary sections are horizontally aligned level and parallel MIL STD 189 spacing Universal spacing Q 2 O O e lt lt lt Mount the 0 500 0 500 Stationary section e i to these holes 0 625 1 250 1 0 625 G T O O Figure 6 28 Rail detail for mounting rack slides 6 46 VM700T Video Measurement Set Service Manual Maintenance Front rack rail Front rail mount Barnut Use if front rack rail is not tapped 10 32 PHS screws Rear rack rail 10 32 PHS S screws E Deep rack mount 4
377. tton changes the function of the control knob from the default Move Expand action to line selection The LED in the Select Line button is on when Select Line is active To scroll through the field line by line press the Select Line button and rotate the control knob Depending on the operational mode a menu of soft keys may also appear when the Select Line button is pressed Refer to the relevant sections of the user documentation for a description of the Select Line soft keys and the specific control knob functions In the diagnostic menus use the Select Line button to activate a selected choice For additional information on diagnostic operation refer to Diagnostics beginning on page 6 55 Equipment Signal Sources Most measurements can only be made using either off air live signals or signals Required from a generator that have the appropriate test signals in the vertical interval No useful measurement information is displayed if the test signals are not correct for the measurement being made Bandwidth bandwidth of the measurement set is 0 Hz DC to approximately 6 8 MHz video signals Connecting Inputs and measurement set has three video loop through inputs one external sync Outputs loop through two RS 232C DTE ports a Centronics compatible printer port and a VGA output connector on the rear panel Figure 2 3 The audio options Option 40 and Option 41 add appropriate connectors for application of the audio sign
378. udes 10 dBu 21 dBu 40 dBu 49 dBu 51 dBu 55 dBu 59 dBu 61 dBu 65 dBu 70 dBu 4 21 Audio Option 41 Triple Input Verification Procedure Check Distortion and Distortion Measurement Accuracy This procedure verifies that residual THD N is lt 0 03 then checks the THD N measurement accuracy by reading a known signal Specification Checked THD N accuracy is 10 of the reading 1 digit for harmonics at input levels of 20 dBu and greater in a 33 Hz to 22 kHz bandwidth Option 41 Distortion 1 Check residual THD N Measurement Accurac Apply a signal between 20 dBu and 30 dBu from a sine wave generator to the VM700T Audio Option See to Figure 4 9 for connec tions b Runthe Audio Analyzer measurement and verify that residual THD N is 0 03 or less An applied signal of 8 to 10 dBu yields optimal reading while a 20 dBu signal yields a worst case reading 2 Check THD N Measurement Accuracy a With 600Q output resistance selected connect the outputs of two sine wave generators in parallel to the left channel of the dual female XLR to DB 37 female adapter cable see Figure 4 9 7 Option 41 audio input connector Odo Figure 4 9 Option 41 cable connections distortion measurement accuracy check b Set one sine wave generator for a 2 V rms output at 1 kHz 4 22 VM700T Video Measurement Set Service Manual Audio Option 41 Triple Input
379. udio Analyzer Frequency Measurement Accuracy Same as Audio Analyzer AN Timing Specifications Option 42 Table 1 94 Audio Video Timing measurement specifications Characteristic Performance requirement Audio Amplitude Window Audio Amplitude Range Timing Range Timing Accuracy 92 dB 102 dB to 30 dB in five ranges 65 ms 1 ms 1 34 VM700T Video Measurement Set Service Manual Specification Option 48 GPIB Specification The GPIB interface function set implemented in the VM 700T GPIB interface and the capability level is given in Table 1 95 Table 1 95 IEEE 488 1 interface functions implemented in the VM700T GPIB interface card Function Implemented Source Handshake SH1 Notes Complete capability Acceptor Handshake AH1 Complete capability Talker T6 Basic Talker Serial Poll UnaddrifMLA Talker extended 0 No capability Listener L4B Basic Listener Unaddr if MTA Listener extended LEO No capability Service Request SR1 Complete capability Remote Local RL2 No local lock out Parallel P oll 0 No capability Device Clear Complete capability Device Trigger No capability Controller C0 No capability Electrical Interface E2 Table 1 96 GPIB Electrical characteristics Characteristic Output Signal Levels Logical 0 2 42 0 V Logicall lt 40 8 V Performance requirement Three state bus drivers Comments IEEE
380. uires access to a radio frequency standard signal If you do not have access to a radio frequency standard signal do not attempt to adjust the frequency of the VM700T genlock crystal oscillator Specification Checked Genlock VCO within 5 Hz of a radio frequency standard 1 MHz signal when checked with the following procedure Single standard instruments either NTSC or PAL need only one VCO checked For dual standard instruments both the PAL and the NTSC VCO must be checked Verifying the Genlock Voltage Controlled Oscillator 1 Connecta radio frequency standard 1 MHz signal to the external reference input of the frequency counter channel B of the example counter 2 Connect the subcarrier output of the appropriate video signal generator NTSC or PAL to the signal input of the frequency counter channel A of the example counter 3 Using the suggested frequency counter the ratio of the channel A to channel B signal is used to determine when the frequency of the test signal is adjusted correctly Adjust the signal generator until the frequency counter displays the exact TV standard subcarrier frequency for the VCO being checked 3 579545 MHz for NTSC or 4 43361875 for PAL 4 Connect the composite video output of the signal generator to the VM700T channel A input terminate channel with the 75 termination VM700T Video Measurement Set Service Manual 5 3 Adjustment Procedure 5 4 5 With the VM700T powered o
381. uity If the cable is good replace the SDI Rear Panel Interface assembly VM700T Video Measurement Set Service Manual 6 103 Troubleshooting Procedures No Signal From the SDI Output Connector Perform the following steps when the SDI Output connector provides no signal but the SDI Ch A and SDI Ch B inputs operate 1 Connect a digital video signal to the SDI Ch A input and terminate the loopthrough connector 2 Connect a cable from the SDI Output connector to SDI Ch B input 3 Check that you can display the SDI Ch B signal on the VM700T NOTE Set the Source Selection Digital configuration file to output the selected channel to the SDI Output connector 4 Ifthere is no signal display disconnect the cable from J10 on the SDI board see Figure 6 65 5 Check the center pin of the J10 connector for a digital video signal 6 If the video signal is not present replace the SDI board 7 Ifthe video signal is present replace the SDI Output cable SDI Option Diagnostics Running the Option 1S 6 104 Diagnostics Option 1S is composed of three modules and two sets of interconnects see Figure 6 66 The SDI and the Acquisition Controller diagnostics effectively identify failures to the Acquisition Controller board the SDI to Acquisition Con troller interconnect and the SDI specific hardware when signal sources are connected as shown in Figure 6 67 Most SDI specific hardware errors occur on th
382. until the measured value is within 0 02 Set the sine wave generator for a frequency of 5 793146 MHz at a level of 3 81 dBm Check to see that the measured amplitude is within 0 55 of the reference level measured in step 30 Power off the VM700T and remove all the test cables Reinstall the instrument cover panels Run the Diagnostics final test is to run the complete set of VM700T diagnostics to verify that the system passes the tests 1 2 Press and hold the Menu button and power on the VM 700T After about 10 seconds you should hear two beeps from the VM 700T Release the Menu button In the VM700T Startup Menu shown in Figure 5 8 use the large control knob to select R Instrument Run Modes Menu VM700T Video Measurement Set Service Manual 5 19 Adjustment Procedure Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu Calibrate TOUCH PANEL INTERFACE A c zu Reprint 8 Abort Menu Input your selection Figure 5 8 VM700T startup menu 4 Press the Select Line button to display the Run Mode Menu shown in Figure 5 9 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection INSTRUMENT RUN MODES MENU Th
383. ute warm up period before starting the verification procedures The instrument must be powered on for at least 20 minutes After a board replacement certain adjustments may be needed to compensate the overall system performance The procedures in this section may be used to make those adjustments NOTE These procedures are not complete board level adjustments Most of the factory adjustments are made during testing before the boards are assembled into the VM700T The adjustments given here are those used to verify and adjust the instrument at the system level 5 2 VM700T Video Measurement Set Service Manual Adjustment Procedure Adjust the Genlock This procedure verifies the VM700T genlock VCO by comparing it to a Voltage Controlled frequency standard and describes the adjustment process if that is needed Oscillator VCO Test Equipment Required m Signal generator Tektronix TSG 170A or equivalent for NTSC or Tektronix TSG 271 or equivalent for PAL Both signal generators are needed for dual standard instruments m Frequency counter with external reference or Ratio Tektronix DC 503A TEGAM DC 503A or equivalent m Digital voltmeter with 3 1 2 digit display m Termination 75 Q precision BNC Tektronix 011 0102 01 Coaxial cables 75 Q high quality noise free BNC 1 meter length 2 each Tektronix 012 0074 00 m Non metallic flat blade adjusting tool Tektronix 003 1364 00 NOTE This procedure req
384. uts to a Signal pin connect Signal pin to shield VM700T Video Measurement Set Service Manual Maintenance Tektronix Supplies a DB 37 mating connector kit for Option 41 users for assembling the signal interconnection cabling The supplied kit provides several sizes of cable adapter collars Select the one fits your cable and put it on the cable before assembling the wiring to the connector as shown in Figure 6 6 See Table 6 2 for the connector pin assignments The connector pin locations are shown in Figure 6 7 The Tektronix part number for the DB 37 connector is 200 3947 00 After assembling the connector and checking out the wiring install the EMI reduction ferrite choke as instructed below Figure 6 6 Orientation of the cable adapter collar Input3 Input2 Inputl right right right Q QUO QUO Q O CO QUO O G LEE Male DB 37 v v v Input3 Input2 1 left left left Figure 6 7 Option 41 Triple Input Audio input connector pin locations Installing the EMI Reduction Ferrite Choke The EMI reduction parts consist of two ferrite forms and two cable tie wraps to secure the ferrite forms on a multicon ductor cable The ferrite forms fit together on a cable that has an outside diameter of 0 5 inch or less The ferrite choke consists of the following parts Ferrite forms 2 ea Tektronix part number 276 0832 00 m Cabl
385. vice Manual 6 101 Troubleshooting Procedures 6 102 10 Yel SDI Se A Green SANT 5 SDI board back side Pin 8 ofj5 N eae Figure 6 65 SDI board cable connections and J5 pinouts No Signal From the Perform the following steps when the VM700T will not display a known signal SDI Ch B Input the SDI Ch B input but the SDI Ch A input operates 1 Connect a digital video signal to the SDI Ch B input and set the VM700T to display the channel B signal Swap the SDI Ch A and SDI Ch B cable connections on the SDI board at J7 and J8 see Figure 6 65 Connect the signal input to the SDI Ch A input connector leave the VM700T front panel set to display the channel B signal Check that there is a signal display If there is still no signal display on channel B replace the SDI board If there is a signal on channel B replace the SDI Ch B cable VM700T Video Measurement Set Service Manual Troubleshooting Procedures No Signal From the Perform the following steps when the Analog Ref input does not operate but the Analog Ref Input SDI Ch A input operates 1 2 Connect an NTSC television signal to the Analog Ref input Check for a video signal on J5 pin 8 on the SDI board Leave the J5 cable installed and probe the board from the bottom as shown in Figure 6 65 If the video signal is present on J5 pin 8 replace the SDI board If the video sig
386. ving instrument covers should be done only by a qualified service person The VM 700T power supply is a high efficiency switching supply Field repairs to a VM700T with a power supply problem are done by board exchange Refer to Exchanging VM 700T Modules on page 6 3 for more information Front Panel Check Check the LED indicators over the front panel STBY ON switch see Figure 6 60 One red LED is an over temperature warning and the other is a power supply failure indicator If the green Power indicator is on primary power is applied the line fuse is good and the housekeeping voltage supply is operating If no indicators come on either the primary power circuitry has failed or the master ON OFF switch is OFF Check the line fuse and the master ON OFF switch to make sure it is on Also make sure the Line Voltage Selector switch is set to the correct supply voltage If the Line Voltage Selector was not set to the correct setting the fuse may have opened If the line fuse is good the master switch is ON the Line Voltage Selector set correctly and the power supply still does not operate troubleshoot the power supply P SFAIL POWER OVER TEMP O O O Figure 6 60 Front panel power supply and over temperature indicators If the Over Temp indicator is on and the instrument is still operating then an over temperature condition exists If the temperature continues to rise a power supply shutdown
387. wed by the No Change amp Exit soft key The measurement verifies that you want to exit the Source Selection Audio directory and cancel any changes by asking you to touch the No Change amp Exit soft key again Check Level Measurement Accuracy and Flatness Specifications Checked Option 41 Level Accuracy and Flatness 4 20 This procedure verifies flatness and measurement accuracy by checking signal levels at specified frequencies NOTE Frequencies and levels checked are not specified in this procedure If the measurement accuracy of certain frequencies and levels is important to your application we recommend that your test procedure include those frequencies and levels Table 4 5 lists audio option accuracy and flatness specifications Table 4 5 Accuracy and flatness specifications Accuracy Frequency Range Level Range 1 includes flatness Flatness 20 40 Hz gt 20 dBu 0 3 0 2 dB 0 1 0 2 dB 20 dBu to 50 dBu 0 4 0 3 dB 0 1 0 2 dB 50 dBu to 60 dBu 0 6 0 5 dB 0 2 0 3 dB 60 dBu to 70 dBu 1 0cB 0 4 0 5 dB 40 Hz 20 kHz gt 20 dBu 0 2 dB 0 1 dB 20 dBu to 50 dBu 0 3 dB 0 1 dB 50 dBu to 60 dBu 0 5 dB 0 2 dB 60 dBu to 70 dBu 1 0 dB 0 4 dB 1 Level difference between channels is 0 2 dB at levels of 50 dBu and greater 1 Power on the VM700T and associated test equipment and let them warm up for 20 minutes 2 Connect the sine w
388. wing steps 1 Turn off the VM700T 2 Press and hold the Menu button as you turn the power back on 3 After the VM700T beeps twice release the Menu button The VM700T Startup Menu is then displayed see Figure 6 40 4 Use the front panel knob to select U in the menu and then press the Select Line button This displays the Utilities Menu shown in Figure 6 41 Low Level Diagnostic Interface knob moves cursor Select Line inputs selection VM700T STARTUP MENU Key Selection Instrument RUN MODES Menu UTILITIES Menu Low Level DIAGNOSTICS Menu Diagnostics CONFIGURATION Menu Diagnostics HELP Menu Calibrate TOUCH PANEL INTERFACE Reprint 8 Abort Menu Input your selection Figure 6 40 VM700T Startup menu Low Level Diagnostic Interface knob moves cursor Select Line inputs selection UTILITIES MENU Key Selection ERROR LOG utilities NVRAM utilities REPROGRAM Instrument Show FIRMWARE Date Codes Show INSTRUMENT ID number Reset Software OPTION KEY D 2 Reprint 8 Abort Menu Input your selection Figure 6 41 Diagnostic Utilities menu 6 66 VM700T Measurement Set Service Manual Troubleshooting Procedures Clearing the CPU NVRAM and FILE SYSTEM NVRAM The diagnostic utilities include the NVRAM utilities These utilities have a couple of uses one is to recover
389. xpand the waveform by touching the waveform and then using the front panel knob to adjust the waveform display 7 Touch the Volt Cursor 2 soft key and then use the front panel knob to position the cursor to the bottom of the sine wave 8 Check that the V2 measurement readout is 770 mV to 820 mV 800 mV 3 8 4 28 VM700T Video Measurement Set Service Manual SDI Option 1 Verification Eye Diagram Frequency frequency response 20 to 80 rise time specification for SDI Eye Response Diagram application is 100 ps for rise times between 400 ps and 1 5 ns Perform the following procedure to check the frequency response of the SDI Eye Diagram application 1 Connect a 50 kHz 1 25 Vpp leveled sine wave through a 50 2 75 converter to the SDI Ch A input Terminate the SDI Ch A input with a 75 Q high frequency terminator NOTE If you are using the Tektronix SG 5030 connect the 50 0 75 converter between the Output Head and the SDI Ch A input no cable between the Output Head and the input 2 Press the 700 front panel Measure button and then touch the SDI Eye Diagram soft key 3 Press the VM700T front panel Menu button Touch the Waveform soft key and then select Free Run on soft key is highlighted 4 Press the 700 front panel Menu button and then touch the Cursors Units softkey 5 Touch the Volt Cursor 1 soft key and then use the fron
390. y Figure 4 4 Power up diagnostics selection display Figure 4 5 Diagnostic selection file showing an unselected choice Figure 4 6 Option 40 cable connections level accuracy and flatness check Figure 4 7 Option 40 cable connections distortion measurement accuracy check 2 25 eed ues EVEN A AUS Figure 4 8 Option 41 cable connections level accuracy and flatness check Figure 4 9 Option 41 cable connections distortion measurement accuracy check 2 2 vere EP EP RETE PX Pes Figure 5 1 Adjustment locations Figure 5 2 VM700T startup menu Figure 5 3 Display monitor centering adjustments Figure 5 4 Touch screen calibration display Figure 5 5 Touch screen calibration Figure 5 6 Panel calibration values Figure 5 7 Example gain phase analyzer flatness waveforms for the VM700T Figure 5 8 VM700T startup menu Figure 5 9 Instrument run modes menu Figure 5 10 Loosening the right side cover Figure 5 11 Cable requirements for adjusting the Cable Meter Figure 5 12 Location of CPU board dip switch and SDI board test poin
391. y modules on the CPU board ty SIMM board socket ty ADC board A3 Faulty analog input board 1 power supply Faulty or blocked cooling fan Loose connections to cooling fan Clogged or dirty front bezel air filters Power supply is in over temperature shutdown mode Faulty monitor pulling down 12 V on power supply Replace the RAM memory SIMM on the CPU board Clean the SIMM board connector Check for firm connection Replace the ADC board Refer to Removing and Replacing the ADC Board Replace analog input board Refer to Removing and Replacing the Analog Input Board Check power supply Refer to Power Supply Diagnostics in this section Check cooling fan for operation and for obstructions blocking air flow Check cooling fan connections Refer to Removing and Replacing the Cooling Fan Clean the front bezel air filters Refer to Cleaning the Front Bezel Air Filters Same as OVERTEMP symptom Diagnose by disconnecting 12 V monitor supply cable P3 at power supply and retrying startup If POWER FAIL status LED does not light with 12 V cable disconnected replace CRT module Faulty power supply Check power supply Referto Power Supply Diagnostics in this section Load on power supply exceeds design limit Check power supply Referto Power Supply Diagnostics in this section VM700T Video Measurement Set Service Manual 6 53 Troubleshooting Proc
392. y Accuracy 0 1 ppm Drift Rate Range 40 ppm s Drift Rate Accuracy 5 ppb s Table 1 102 SDI Interchannel Timing application Characteristic Performance requirement Supplemental information Digital to Digital Accuracy 1 sample Range 0 5 frame Digital to Analog Accuracy 400 ns Range 0 5 frame Table 1 103 SDI Audio Video Timing application Characteristic Performance requirement Embedded Signal Accuracy 200 us Range External Signal Accuracy 200 us Range VM700T Video Measurement Set Service Manual Supplemental information 2 seconds less range on data streams heavily loaded with ancillary data 2 seconds 1 39 Specification Table 1 104 SDI Ch A Input Characteristic Performance requirement Electrical Characteristics Input type BNC passive loopthrough 15 compensated Return Loss Supplemental information Power On gt 25 dB 1 MHz to 360 MHz Channel on or off Power Off gt 15 dB 1 MHz to 360 MHz Insertion Loss Power On 0 3 dB 1 MHz to 360 MHz Power Off 1 0 dB 1 MHz to 360 MHz Signal Characteristics Amplitude Range 800 mV 15 25 Frequency Range 143 Mb s 20 ppm 270 Mb s 20 ppm 360 Mb s 20 ppm J itter Maximum for No Bit Errors 143 Mb s 2 ns pk to pk for frequencies of 160 kHz and above Max jitter ns 320 jitter frequency KHz for frequencies below 160 kHz 270 Mb s 1 ns pk to pk for frequencies of 160 kHz and above Max jitte
393. y for the Diagnostic Errors file is 100 lines If the number of errors detected produces a longer file the earliest results are scrolled out and a message stating that fact is included VM700T Video Measurement Set Service Manual Troubleshooting Procedures Low Level Diagnostic Interface knob moves cursor Select Line inputs selection INSTRUMENT RUN MODES MENU The instrument will be reset to run in the mode selected below overriding current boot switch settings Key Selection Current Powerup Mode is QUICK START abort this menu and go to the DIAGNOSTICS CONFIGURATION MENU to change it POWERUP 5 4 4554 54 24 Da Diagnostics start Instrument Q us QUICK STAR Trasse anes Skip Diagnostics start Instrument L LOW LEVEL DIAGS LOOP Loop on Low Level Diagnostics D HIGH LEVEL DEBUG Start Instrument in HL Debug Mode AUTORESET Lie eni Do EXTRA Diagnostics start Instrument Reprint 8 Abort Menu Input your selection Figure 6 56 Instrument Run Modes menu Viewing Diagnostics You will not be able to view diagnostic results if the VM 700T display either is Remotely not operating or is operating improperly The VM 700T supplies a method known as Debug mode to view diagnostic results on a terminal or PC should the display be malfunctioning You can isolate a display problem to the display monitor by viewing the ou
394. zeros all ones normal and overflow bit modes and checks the ADC output by running an acquisition and scanning Successful completion of acquired data The overflow bit test generates a drive level to these tests requires that overrange the board then acquires data and checks to verify that the Genlock A2 and board s overrange bit was set Acquisition Memory A18 boards be oper ating correctly Uses Controller state machine to toggle offset level a dynamic setting on the Analog Input board while a long acquisition runs Analyzes the acquired data to detect missing samples Bit Patterns Generates a calibration DAC drive level that produces an ADC level corresponding to the bit pattern shown in the individual test The diagnostic runs a long acquisition and searches the acquired data for the individual test s bit pattern DVM Calibrates the DVM to the standard gating patterns for both TV standards and the gating pattern that enables the DVM for all video lines using a precise 1 000 volt reference and ground 1 Checks that a nominal DC voltage can be routed through each input channel to the ADC E Gain Control Checks gain control range and bit weights Calibration DAC Checks the range and bit weights of the calibration DAC Offset Control Checks the range and bit weights of the offset control DAC Input S election Checks the input selection switch by setting the channel bias DACs to different levels on each chann

Service Manual VM700T Video Measurement Set 070-9630-04

Contents

Download Pdf Manuals

Related Search

Related Contents