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SR785 Service Manual - Stanford Research Systems

1. Before proceeding reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the Analog boards in the Analyzer card cage behind the input BNC connectors Remove the card cage cover by loosening the five screws in the cover The Channel 1 Analog board is in the center of the card cage The Channel 2 Analog board is on the right Pull off the small shield at the front using the finger hole Remove the correct Analog board by using the card ejectors to release the board and pull the board up and out SR785 Dynamic Signal Analyzer 3 20 Service 7 Use the DVM to verify that the A input BNC center conductor and shield are connected to the front most SMB jack at the bottom of the card cage directly behind the inputs The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield Use the DVM to verify that the B input BNC connects properly to the rear most SMB jack If both connections are OK procee
2. Connect the frequency synthesizer output to both the Ch1 A and Chl B inputs of the analyzer Use equal length cables from A and B to a BNC TEE Connect the cable from the synthesizer output to the TEE Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 1 kHz and an amplitude of 500 mVrms 3 Setup the measurement Press the keys in the following sequence Freq lt Span gt 1 6 Select kHz Enter lt Center Freq gt 1 Select kHz Enter Input lt Input Config gt Chl Input Range 2 Enter Average Averaging Type Select Linear Fixed Len Enter it Avgs gt 1 0 Enter Display Avg Select RMS Enter Wait for the average to finish Auto Scale A Marker Max Marker Ref Input Input Config Chl Input Mode Select A B Enter SR765 Dynamic Signal Analyzer 1 12 Performance Tests Start Reset Wait for the average to finish 4 Record the marker Y reading This is the Chl CMRR in dB at 1 kHz 5 Move the input cables from Ch1 A and B to Ch2 A and B Repeat the measurement for Ch2 Press the keys in the following sequence Active Display Make DisplayB the active display Input Channel Select Ch2 Enter Ch2 Input Range 2 Enter Start Reset Wait for the average to finish Auto Scale B Marker Max Marker Ref Input
3. Analyzer Backplane NIMM Front Both the system and the analyzer backplanes are passive and contain no active circuitry They only provide power distribution signal routing between the various boards and to external ports or devices Schematic Diagram Locations Schematic diagrams are located in Chapter 5 Board Assembly Schematic s see Chapter 5 CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Board MKEY 1 DSP Board D785 1 through D785 11 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 SR765 Dynamic Signal Analyzer Service Guide Circuit Description 2 5 CPU Board This section covers schematics MCPU 1 through MCPU 9 in Chapter 5 The CPU board contains the main microprocessor system CPU memory front panel and printer interfaces are on this board Two off board data buses are also driven from this board The I O Expansion data bus connects the CPU board with the Video IO and Aux slots on the System backplane The External data bus connects to the DSP Board via the Analyzer backplane Microprocessor System The microprocessor U101 is an 80C186XL or 80C186EA microcontroller which integrates a fast 16 bit processor counter timers interrupt controller DMA controller and I O decoding into a single component The 80C186 is clo
4. R 112 0 00001 000 WIRE Hardware Misc R 113 0 00001 000 WIRE Hardware Misc R 114 0 00001 000 WIRE Hardware Misc R 115 0 00001 000 WIRE Hardware Misc R 116 0 00001 000 WIRE Hardware Misc SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 17 DSP Board Assembly Ref No SRS Part No Value Component Description R 301 4 00079 401 4 7K Resistor Carbon Film 1 4W 5 R 302 4 00079 401 4 7K Resistor Carbon Film 1 4W 596 R 501 4 00177 407 3 48K Resistor Metal Film 1 8W 1 50PPM R 502 4 00177 407 3 48K Resistor Metal Film 1 8W 1 50PPM R 504 4 00771 407 66 5 Resistor Metal Film 1 8W 1 50PPM R 505 4 00163 407 2 80K Resistor Metal Film 1 8W 1 50PPM R 506 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1 25ppm R 507 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1 25ppm R 508 4 00467 407 2 43K Resistor Metal Film 1 8W 1 50PPM R 509 4 00193 407 499 Resistor Metal Film 1 8W 1 SOPPM R 510 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R511 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1 25ppm R512 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1 25ppm R513 4 00746 407 2 05K Resistor Metal Film 1 8W 1 50PPM R514 4 00317 407 422 Resistor Metal Film 1 8W 1 50PPM R515 4 00652 407 1 58K Resistor Metal Film 1 8W 1 50PPM R 516 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1 25ppm R 517 4 00409 408 1 210K Resistor Metal Film 1 8W 0 1
5. 50PPM R 33 4 00705 407 5 62K Resistor Metal Film 1 8W 1 50PPM R41 4 00034 401 10K Resistor Carbon Film 1 4W 5 R42 4 00522 407 243 Resistor Metal Film 1 8W 1 50PPM R 43 4 00705 407 5 62K Resistor Metal Film 1 8W 1 50PPM TP1 1 00143 101 TEST JACK Vertical Test Jack TP2 1 00143 101 TEST JACK Vertical Test Jack TP3 1 00143 101 TEST JACK Vertical Test Jack TP4 1 00143 101 TEST JACK Vertical Test Jack TPS 1 00143 101 TEST JACK Vertical Test Jack TP10 1 00143 101 TEST JACK Vertical Test Jack TP11 1 00143 101 TEST JACK Vertical Test Jack TP12 1 00143 101 TEST JACK Vertical Test Jack TP13 1 00143 101 TEST JACK Vertical Test Jack TP14 1 00143 101 TEST JACK Vertical Test Jack TP15 1 00143 101 TEST JACK Vertical Test Jack TP16 1 00143 101 TEST JACK Vertical Test Jack TP17 1 00143 101 TEST JACK Vertical Test Jack TP18 1 00143 101 TEST JACK Vertical Test Jack TP19 1 00143 101 TEST JACK Vertical Test Jack TP20 1 00143 101 TEST JACK Vertical Test Jack TP21 1 00143 101 TEST JACK Vertical Test Jack TP22 1 00143 101 TEST JACK Vertical Test Jack TP23 1 00143 101 TEST JACK Vertical Test Jack U10 3 00149 329 LM317T Voltage Reg TO 220 TAB Package Ul 3 00141 329 LM337T Voltage Reg TO 220 TAB Package U20 3 00149 329 LM317T Voltage Reg TO 220 TAB Package U21 3 00141 329 LM337T Voltage Reg TO 220 TAB Package U 30 3 00096 340 LM317L Integrated Circuit Thru hole Pkg U 40 3 00096 340 LM317L Integrated Circuit Thru h
6. Auto Scale A Auto Scale B If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Low Gain Offset pot to minimize the marker reading see Fig 8 3 12 Connect the Source Output to both the Ch1 A and B inputs Ch2 A and B Use equal length cables from A and B to a BNC TEE Connect the cable from the Source Output to the TEE Press Source On Sine Frequency 1 1 0 2 4 Select KHz Enter Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 2 Enter Auto Scale A Auto Scale B Use the knob to move the marker to 1 024 kHz The amplitude should be 6 dBV Marker Ref Marker now reads relative to the signal amplitude SR765 Dynamic Signal Analyzer Service Guide Service 3 27 Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Mode Ch2 Input Mode Select A B Enter Do not move the marker The marker reading is the common mode rejection ration CMRR If the reading is below 100 dB then do not make any adjustment If the reading is above 100 dB then adjust the High Gain CMR pot to minimize the reading see Fig 8 3 13 Press Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 0 Enter
7. Remove the DSP board by using the card ejectors to release the board and pull the board up and out Use the DVM to verify that the Source Output BNC center conductor and shield are connected to the front most SMB jack at the bottom of the card cage directly behind the Source Output The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield If the connection is OK follow Procedure F1 to replace the DSP board Otherwise contact SRS for more information Service Procedure F7 DSP Memory Module Replacement 1 2 Service Guide Before replacing a memory module reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module SR785 Dynamic Signal Analyzer 3 22 Service 10 11 Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the DSP board in the Analyzer card cage nearest the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP board by using the card ejectors to release the board and pull the boar
8. To prevent damage to the input FET the input voltage is monitored by comparators U106 and U107 High voltages cause the input attenuator to be automatically engaged regardless of the user gain setting at the front panel Resistors R107 and R108 provide some input protection to the input FET with only a slight penalty in input voltage noise The input FET U100 is an extremely low noise matched pair of FET s with a voltage input noise of approximately 3 5 nV VHz To improve distortion performance the input FET s are cascoded to maintain a constant drain source voltage across each FET This prevents modulation of the drain source voltage by the input voltage U104 senses the source voltage and maintains the same voltage at the drain with some DC offset determined by resistors N102 and N103 U103B provides common mode feedback and maintains a constant drain current in each FET U105 provides the single ended output The gain of the front end is either 10 dB or 20 dB as selected by relay K107 When a gain of 10 dB is selected the offset and CMR are adjusted via P104 and P103 respectively When a gain of 20 dB is selected offset and CMR are adjusted via P102 and P101 respectively Gain Stages And Attenuators Collectively the front end amplifier gain stages and attenuators provide sensitivity ranges from 50 dBV to 34 dBV This is accomplished through the front end amplifier two gain stages and a resistive ladder attenuator Service Guide SR78
9. 20 Rad C 502 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 505 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 506 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 507 5 00148 545 1000P Capacitor Monolythic Ceramic COG 146 C 508 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 509 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C510 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C511 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 513 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C514 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL C515 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C516 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C517 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 520 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C521 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL C 530 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C531 5 00053 512 033U Cap Stacked Metal Film 50V 5 40 85c C 532 5 00052 512 01U Cap Stacked Metal Film 50V 5 40 85c C 533 5 00050 566 0033U Cap Polyester Film 50V 5 40 85c Rad C 534 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 550 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C551 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 554 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C555 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z
10. 25ppm R 518 4 00523 407 649 Resistor Metal Film 1 8W 1 50PPM R 519 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 520 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM R 521 4 00136 407 1 82K Resistor Metal Film 1 8W 1 50PPM R 522 4 00654 407 182 Resistor Metal Film 1 8W 1 50PPM R 523 4 00356 407 20 Resistor Metal Film 1 8W 1 50PPM R 524 4 00057 401 220 Resistor Carbon Film 1 4W 5 R 525 4 00233 424 47 Resistor Carbon Comp 2W 5 R 527 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 530 4 00479 407 66 5K Resistor Metal Film 1 8W 1 50PPM R 531 4 00457 407 33 2K Resistor Metal Film 1 8W 1 50PPM R 532 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 533 4 00161 407 2 49K Resistor Metal Film 1 8W 1 50PPM R 534 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 535 4 00066 401 3 3M Resistor Carbon Film 1 4W 5 R 536 4 00210 407 9 09K Resistor Metal Film 1 8W 1 50PPM R 537 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM R 570 4 00107 402 10 Resistor Carbon Comp 1 2W 5 R571 4 00107 402 10 Resistor Carbon Comp 1 2W 5 R 572 4 00080 401 47 Resistor Carbon Film 1 4W 5 R 573 4 00080 401 47 Resistor Carbon Film 1 4W 5 R 600 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 601 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 602 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 603 4 00032 401 100K Resistor Carbon Film 1 4W 5 R 604 4
11. 50V 80 20 Z5U AX C 1409 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1410 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1411 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1412 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1413 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1414 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1415 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1416 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1417 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1418 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1419 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1420 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1440 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1441 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1442 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1445 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1446 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1447 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1450 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1451 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1452 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1453 5 00100 517 2 2U Capacitor T
12. C182 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 201 5 00008 501 22P Capacitor Ceramic Disc 50V 10 SL C 202 5 00005 501 150P Capacitor Ceramic Disc 50V 10 SL C 203 5 00017 501 47P Capacitor Ceramic Disc 50V 10 SL C 204 5 00008 501 22P Capacitor Ceramic Disc 50V 10 SL C 205 5 00005 501 150P Capacitor Ceramic Disc 50V 10 SL C 206 5 00017 501 47P Capacitor Ceramic Disc 50V 10 SL C210 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C211 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C212 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 213 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C214 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C215 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C216 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C217 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C218 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C219 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 220 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C221 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C222 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 223 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 224 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 225 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 226 5 00148 545 1000P Capacitor Monolythic Ceramic
13. COG 1 C227 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 228 5 00148 545 1000P Capacitor Monolythic Ceramic COG 1 C 229 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 230 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 250 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C251 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 252 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad Service Guide SR785 Dynamic Signal Analyzer 4 22 Parts Lists Analog Input Board Assembly Ref No SRS Part No Value Component Description C 253 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 254 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 255 5 00023 529 IU Cap Monolythic Ceramic 50V 20 Z5U C 256 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 257 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 258 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 259 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 260 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 261 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 262 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 263 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 264 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 265 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 266 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 267 5 00100 517 2 2U Capacitor
14. Chl Input Mode Ch2 Input Mode Select A Enter Auto Scale A Auto Scale B Marker Ref Marker now reads absolute signal amplitude Use the knob to move the marker to 1 024 kHz The amplitude should be 6 dBV Marker Ref Marker now reads relative to the signal amplitude Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Mode Ch2 Input Mode Select A B Enter Do not move the marker The marker reading is the common mode rejection ration CMRR If the reading is below 80 dB then do not make any adjustment If the reading is above 80 dB then adjust the Low Gain CMR pot to minimize the reading see Fig 8 3 14 Remove the cables from the A and B inputs Connect a 50Q termination to the Chl Ch2 A input This shorts the input to ground so the analyzer s own DC offset is measured Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 5 0 Enter Service Guide SR785 Dynamic Signal Analyzer 3 28 Service Chl Input Mode Ch2 Input Mode Select A Enter Marker Ref Marker now reads absolute signal amplitude Use the knob to move the marker to 0 Hz The marker position should display 0 Hz The marker reading is the DC offset Auto Scale A Auto Scale B If the marker reading is less than 85 dBV remember 80 dBV is greater than 85 dBV and 90 dBV is less than 85 dBV then proceed to the next ste
15. Connect a 50Q feedthrough termination to the Chl A and Ch2 A inputs This shorts the inputs so the analyzer s own DC offset will be measured Procedure 1 Reset the unit by pressing System Preset and then Enter to confirm 2 Press the keys in the following sequence Freq Span 1 6 select KHz Enter Marker Marker Select Link Enter Use the knob to move the markers to 0 Hz Average Averaging Type Select Linear Fixed Length Enter lt Avgs gt 1 0 Enter Display Average Select RMS Enter 3 a Press Input Input Configuration Chl Input Range Channel Select Both Enter Chl Input Range 3 0 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B b Record the marker Y values for both displays on the 30 dBV range c Press Chl Input Range SR765 Dynamic Signal Analyzer 1 10 Performance Tests 5 0 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B d Record the marker Y values for both displays for the 50 dBV range 4 This completes the DC measurement test Enter the results of this test in the test record at the end of this section SR785 Dynamic Signal Analyzer Performance Tests 1 11 3 Common Mode Rejection This test measures the common mode rejection of the analyzer inputs Setup We will use the frequency synthesizer to provide the signal
16. Enter Averaging Type Select Linear Enter 4 Record the marker Y readings for both displays Make sure that the marker frequency is 10 24 kHz 5 This completes the phase accuracy test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer Performance Tests 1 25 9 Noise and Spurious Signals This test measures the analyzer noise floor and checks for spurious signals Setup Connect 50Q feedthrough terminations to the Chl A and Ch2 A inputs This grounds the inputs so the analyzer s input noise is measured Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Freq lt Span gt 5 1 2 Select kHz Enter lt Start Freq gt 5 1 2 Select Hz Enter Window lt Window gt Select Hanning Enter Input lt Input Config gt lt Channel gt Select Both Enter Chl Input Range gt 5 0 Enter Chl Coupling Select AC Enter Chl Grounding gt Select Ground Enter Display Setup Y mid Link 1 5 0 Enter Display Options Units lt PSD Units Link Select On Enter Pk Units Link Select rms Enter SR785 Dynamic Signal Analyzer 1 26 Performance Tests Average lt Avgs gt 2 0 Enter Averaging Type Select Linear Fix Len Enter Display Avg Select RMS Enter
17. Tantalum 35V 20 Rad C 268 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 269 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 270 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C271 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C272 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 273 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C274 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 275 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 276 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C277 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 278 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 279 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 280 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 281 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 282 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C301 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C310 5 00049 566 001U Cap Polyester Film 50V 5 40 85c Rad C311 5 00056 512 JU Cap Stacked Metal Film 50V 5 40 85c C312 5 00056 512 JU Cap Stacked Metal Film 50V 5 40 85c C313 5 00056 512 1U Cap Stacked Metal Film 50V 5 40 85c C314 5 00317 501 750P Capacitor Ceramic Disc 50V 10 SL C315 5 00056 512 JU Cap Stacked Metal Film 50V 5 40 85c C341 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 342 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 354 5 00100 517 2 2U C
18. Z5U AX C 969 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 970 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C971 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 972 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 973 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 974 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 975 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 976 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C977 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 978 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 979 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 980 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 981 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 982 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 983 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 984 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 985 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 986 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 987 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 988 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 989 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 990 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80
19. paths present If the DSP or Analog boards are not present then the voltages labeled ANLG CH1 30V CH2 30V and DIG must be measured relative to the AGND CHIRET CH2RET and DGND test points Assuming that all other boards are present connect the negative lead of the DVM to the chassis Use the positive lead to measure the test points along the top of the power supply board starting at the rear Digital Power Test Point Nominal 12V 12V 45 5V 5V 5 12V 12V 45 5V 5V 5 Ground OV ANLG Power Test Point Nominal 28V lt 23V 28V gt 23V 20V 20V 5 20V 20V 5 AGND OV CH2 Test Point Nominal 30V 30V 5 RET OV CH1 Test Point Nominal 30V 30V 45 RET OV SR785 Dynamic Signal Analyzer Service Guide 10 Service 3 13 DIG Power Test Point Nominal 28V lt 23V 28V gt 23V 20V 20V 5 20V 20V 5 DGND OV If the supplies check ok then replace the top lid and refasten the eight lid screws If the supplies are not correct try one or both of the following A Follow procedure A1 to replace the power supply board and repeat this check B Remove one or more of the other boards and recheck the power supply This assumes that the supply voltage is being affected by a bad board elsewhere in the unit The Digital power drives the CPU Video IO Disk cards and the CRT assembly The ANLG and CH1 power drives the Ch1 analog input board The ANLG and CH2 power drives the Ch2 anal
20. 1 8W 1 50PPM R 317 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R318 4 00166 407 200K Resistor Metal Film 1 8W 1 50PPM R 320 4 00176 407 3 01K Resistor Metal Film 1 8W 1 50PPM R 321 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 335 4 00059 401 22K Resistor Carbon Film 1 4W 5 R 350 4 00031 401 100 Resistor Carbon Film 1 4W 5 R351 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 352 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 353 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 354 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 355 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 356 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 357 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 360 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 361 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 362 4 00185 407 4 02K Resistor Metal Film 1 8W 1 50PPM R 363 4 00161 407 2 49K Resistor Metal Film 1 8W 1 50PPM R 364 4 00161 407 2 49K Resistor Metal Film 1 8W 1 50PPM R 370 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 371 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM R 372 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 373 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 374 4 00395 407 316K Resistor Metal Film 1 8W 1 50PPM R 375 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 378 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 379 4 00031 40
21. 100K Resistor Metal Film 1 8W 1 50PPM R 232 4 00348 407 2 21K Resistor Metal Film 1 8W 1 50PPM R 233 4 00765 407 56 2 Resistor Metal Film 1 8W 1 50PPM R 234 4 00475 407 2 61K Resistor Metal Film 1 8W 1 50PPM R 235 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 236 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 237 4 00467 407 2 43K Resistor Metal Film 1 8W 1 SOPPM R 238 4 00698 407 357 Resistor Metal Film 1 8W 1 50PPM R 239 4 00582 407 2 15K Resistor Metal Film 1 8W 1 50PPM R 240 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 241 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 242 4 00159 407 2 10K Resistor Metal Film 1 8W 1 50PPM R 243 4 00429 407 511 Resistor Metal Film 1 8W 1 50PPM R 244 4 00136 407 1 82K Resistor Metal Film 1 8W 1 50PPM R 245 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 246 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 247 4 00137 407 1 91K Resistor Metal Film 1 8W 1 50PPM R 248 4 00583 407 309 Resistor Metal Film 1 8W 1 50PPM R 249 4 00699 407 1 54K Resistor Metal Film 1 8W 1 50PPM R 250 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R251 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 252 4 00200 407 619 Resistor Metal Film 1 8W 1 50PPM R 253 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 254 4 00130 407 1 00K Resistor Metal Film 1 8W 1
22. 101 TEST JACK Vertical Test Jack TP302 1 00143 101 TEST JACK Vertical Test Jack TP303 1 00143 101 TEST JACK Vertical Test Jack TP304 1 00143 101 TEST JACK Vertical Test Jack TP401 1 00143 101 TEST JACK Vertical Test Jack TP402 1 00143 101 TEST JACK Vertical Test Jack TP403 1 00143 101 TEST JACK Vertical Test Jack TP404 1 00143 101 TEST JACK Vertical Test Jack TP501 1 00143 101 TEST JACK Vertical Test Jack TP502 1 00143 101 TEST JACK Vertical Test Jack TP511 1 00143 101 TEST JACK Vertical Test Jack TP521 1 00143 101 TEST JACK Vertical Test Jack TP522 1 00143 101 TEST JACK Vertical Test Jack TP531 1 00143 101 TEST JACK Vertical Test Jack TP532 1 00143 101 TEST JACK Vertical Test Jack TP541 1 00143 101 TEST JACK Vertical Test Jack SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 29 Analog Input Board Assembly Ref No SRS Part No Value Component Description TP542 1 00143 101 TEST JACK Vertical Test Jack TP551 1 00143 101 TEST JACK Vertical Test Jack TP690 1 00143 101 TEST JACK Vertical Test Jack U 101 3 00246 340 NPD5564 Integrated Circuit Thru hole Pkg U 102 3 00817 340 NPD5566 Integrated Circuit Thru hole Pkg U 103 3 00461 340 OPA2604 Integrated Circuit Thru hole Pkg U 104 3 00461 340 OPA2604 Integrated Circuit Thru hole Pkg U 105 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 106 3 00143 340 LM393 Integrated Circuit Thru hole Pkg U 107 3 00143 340 LM393 Inte
23. 3 00596 360 DP8473AV Integrated Circuit Surface Mount Pkg U 1202 3 00645 340 NAT9914BPD Integrated Circuit Thru hole Pkg U 1203 3 00078 340 DS75160A Integrated Circuit Thru hole Pkg U 1204 3 00079 340 DS75161A Integrated Circuit Thru hole Pkg U 1301 3 0005 1 340 7T4HCU04 Integrated Circuit Thru hole Pkg U 1303 3 00247 340 SCN2641 Integrated Circuit Thru hole Pkg U 1304 3 00110 340 MC1489 Integrated Circuit Thru hole Pkg U 1305 3 00109 340 MC1488 Integrated Circuit Thru hole Pkg U 1401 3 00342 340 T4ALS 138 Integrated Circuit Thru hole Pkg U 1402 3 00342 340 T4ALS 138 Integrated Circuit Thru hole Pkg X 1201 6 00068 620 24 000 MHZ Crystal X 1301 6 00037 620 3 6864 MHZ Crystal Z0 0 00373 000 CARD EJECTOR Hardware Misc SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 9 Power Supply Board Parts List This section covers schematics MPWR 1 through MPWR 2 in Chapter 5 Power Supply Board Assembly Ref No SRS Part No Value Component Description C1 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C2 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C3 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL C4 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C5 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C6 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL C 10 5 00124 526 5600U Capacitor Electrolytic 35V 20 Rad C11 5 00124 526 5600U C
24. 50PPM R 255 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 256 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 257 4 00577 407 1 21K Resistor Metal Film 1 8W 1 50PPM R 258 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 260 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 261 4 00448 407 8 87K Resistor Metal Film 1 8W 1 50PPM R 262 4 00448 407 8 87K Resistor Metal Film 1 8W 1 50PPM R 263 4 00739 407 113 Resistor Metal Film 1 8W 1 50PPM R 264 4 00894 407 5 23K Resistor Metal Film 1 8W 1 50PPM R 265 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 266 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 267 4 00237 407 4 87K Resistor Metal Film 1 8W 1 50PPM R 268 4 00280 407 715 Resistor Metal Film 1 8W 1 50PPM R 269 4 00895 407 4 32K Resistor Metal Film 1 8W 1 50PPM R 270 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R271 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 272 4 00186 407 4 22K Resistor Metal Film 1 8W 1 50PPM R 273 4 00308 407 1 02K Resistor Metal Film 1 8W 1 50PPM R 274 4 00444 407 3 65K Resistor Metal Film 1 8W 1 50PPM R 275 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 276 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 277 4 00178 407 3 83K Resistor Metal Film 1 8W 1 50PPM SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 27 Analog Input Board Assembl
25. 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 930 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C931 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 932 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 933 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 934 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 935 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 936 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 937 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 938 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 939 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 950 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C951 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad Service Guide SR785 Dynamic Signal Analyzer 4 4 Parts Lists CPU Board Assembly Ref No SRS Part No Value Component Description C 952 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 953 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 954 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C955 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 956 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C957 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 958 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C959 5 00100 517 2 2U Capacitor Tan
26. Accuracy Frequency Trigger Source 95 9976 kHz Lower Limit Upper Limit DispA Ch1 96 0024 kHz DispB Ch2 lt 90 dB Upper Limit 10 24 kHz Chl Noise and Spurious Signals Noise floor 03 0 deg 512 Hz 51 2 kHz Spurious signals Start Frequency Center Frequency Span 51 2 kHz 51 2 kHz Span 230 Hz 500 Hz 1 kHz 5 kHz 10 kHz 25 kHz 50 kHz 75 kHz 101 kHz 400 Hz 400 Hz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz DispA Chl DispB Ch2 87 0 deg Upper Limit DispA Chl DispB Ch2 160 dBVrms VHz 160 dBVrms VHz Upper Limit 135 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk SR765 Dynamic Signal Analyzer 1 34 Performance Tests SR785 Performance Test Record Page 3 of 3 10 Sine Source Amplitude Frequency Lower Limit Upper Limit 1 kHz 0 3 dBV 0 3 dBV 1 kHz 20 3 dBV 19 7 dBV 1 kHz 40 3 dBV 39 7 dBV Amplitude Flatness Frequency Level Lower Limit Upper Limit 20 48 kHz 1000 mV 0 3 dBV 0 3 dBV 40 96 kHz 1000 mV 0 3 dBV 0 3 dBV 61 44 kHz 1000 mV 0 3 dBV 0 3 dBV 81 92 kHz 1000 mV 0 3 dBV 0 3 dBV 99 072 kHz 1000 mV 0 3 dBV 0 3 dBV 11 Harmonic Distortion Fundamental DispATHD DispB THD Upper Limit 10 24 kHz 80 dB SR765 Dynamic Signal Analyzer e sae Chapter 2 Circuit Description This chapter provides descriptions of the circuitry
27. Demo Filter Board Parts List Miscellaneous Parts List Service Guide 12 13 21 31 34 35 SR785 Dynamic Signal Analyzer 4 2 Parts Lists SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 3 CPU Board Parts List This section covers schematics MCPU 1 through MCPU 9 in Chapter 5 CPU Board Assembly Ref No SRS Part No Value Component Description BT701 6 00001 612 BR 2 3A 2PIN PC Battery C101 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 102 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 401 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 602 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 603 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 701 5 00064 513 0047U Capacitor Mylar Poly 50V 596 Rad C 704 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 705 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 706 5 00022 501 001U Capacitor Ceramic Disc 50V 1096 SL C 901 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 902 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 903 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 904 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C905 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 906 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 907 5 00262 548 01U AXIAL Capacitor Cera
28. Film 1 8W 1 50PPM R 206 4 00380 407 6 34K Resistor Metal Film 1 8W 1 50PPM R 207 4 00556 407 2 94K Resistor Metal Film 1 8W 1 50PPM R 208 4 00164 407 20 0K Resistor Metal Film 1 8W 1 50PPM R 209 4 00556 407 2 94K Resistor Metal Film 1 8W 1 50PPM R 210 4 00764 407 9 31K Resistor Metal Film 1 8W 1 50PPM R211 4 00568 407 215 Resistor Metal Film 1 8W 1 50PPM R 212 4 00543 407 169 Resistor Metal Film 1 8W 1 50PPM R 213 4 00873 407 137 Resistor Metal Film 1 8W 1 50PPM R214 4 00144 407 107 Resistor Metal Film 1 8W 1 50PPM R 215 4 00874 407 84 5 Resistor Metal Film 1 8W 1 50PPM Service Guide SR785 Dynamic Signal Analyzer 4 26 Parts Lists Analog Input Board Assembly Ref No SRS Part No Value Component Description R 216 4 0067 1 407 332 Resistor Metal Film 1 8W 1 50PPM R 220 4 00059 401 22K Resistor Carbon Film 1 4W 5 R 221 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 222 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 223 4 00553 407 2 55K Resistor Metal Film 1 8W 1 50PPM R 224 4 00553 407 2 55K Resistor Metal Film 1 8W 1 50PPM R 225 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 226 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 227 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 228 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 230 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 231 4 00142 407
29. Pkg U 601 3 00467 340 T4HCT74 Integrated Circuit Thru hole Pkg U 603 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 606 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 607 3 00454 340 74HC574 Integrated Circuit Thru hole Pkg U 608 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 609 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 610 3 00467 340 74HCT74 Integrated Circuit Thru hole Pkg U 611 3 00467 340 7AHCT74 Integrated Circuit Thru hole Pkg U 612 3 00039 340 74HC14 Integrated Circuit Thru hole Pkg U701 3 00594 340 MAX693A Integrated Circuit Thru hole Pkg U 702 3 00900 340 DS12C887 Integrated Circuit Thru hole Pkg U 703 3 00046 340 74HC374 Integrated Circuit Thru hole Pkg U 704 3 00263 340 DS75451N Integrated Circuit Thru hole Pkg U 705 3 00039 340 74HC14 Integrated Circuit Thru hole Pkg Z0 0 00089 033 4 Tie Z0 0 00373 000 CARD EJECTOR Hardware Misc Service Guide SR785 Dynamic Signal Analyzer 4 6 Video IO Board Parts List Parts Lists This section covers schematics MVID 10 through MVID 14 in Chapter 5 Video IO Board Assembly Ref No SRS Part No Value Component Description C1101 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 1102 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 1103 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 1105 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 1
30. RT ANGLE JACK SMB Connector J 901 1 00234 109 96 PIN RT ANGLE DIN Connector Male J 902 1 00234 109 96 PIN RT ANGLE DIN Connector Male JP301 1 00239 135 72 PIN SIMM Connector Card Edge K 501 3 00444 335 BS 211 DC5 GF Relay K 601 3 00196 335 HS 212S 5 Relay K 602 3 00196 335 HS 212S 5 Relay K 603 3 00196 335 HS 212S 5 Relay K 614 3 00444 335 BS 211 DC5 GF Relay K 615 3 00444 335 BS 211 DC5 GF Relay K 701 3 00444 335 BS 211 DC5 GF Relay L701 6 00180 603 560U Inductor Axial N 101 4 00270 425 1 0KX5 Resistor Network SIP 1 4W 2 Common N 501 4 00262 425 100X7 Resistor Network SIP 1 4W 2 Common N 502 4 00262 425 100X7 Resistor Network SIP 1 4W 2 Common N 601 4 00856 421 1 0KX5 Res Network SIP 1 4W 2 Isolated N 602 4 00856 421 1 0KX5 Res Network SIP 1 4W 2 Isolated N 702 4 00852 420 82X8 Resistor Network DIP 1 4W 2 8 Ind N 703 4 00265 421 100X4 Res Network SIP 1 4W 2 Isolated N 801 4 00690 421 3 3KX4 Res Network SIP 1 4W 2 Isolated N 802 4 00767 420 270X8 Resistor Network DIP 1 4W 2 8 Ind N 803 4 00767 420 270X8 Resistor Network DIP 1 4W 2 8 Ind PCI 7 00762 701 SR785 DSP Printed Circuit Board Q701 3 00022 325 2N3906 Transistor TO 92 Package Q 702 3 00022 325 2N3906 Transistor TO 92 Package R 101 4 00029 401 1 8K Resistor Carbon Film 1 4W 5 R 102 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 103 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 111 0 00001 000 WIRE Hardware Misc
31. Test Jack TP104 1 00143 101 TEST JACK Vertical Test Jack TP105 1 00143 101 TEST JACK Vertical Test Jack TP106 1 00143 101 TEST JACK Vertical Test Jack U 1001 6 00178 621 19 590 MHZ Crystal Oscillator U 1002 3 00274 340 T4AC74 Integrated Circuit Thru hole Pkg U 1003 3 00598 340 63484P 98 Integrated Circuit Thru hole Pkg U 1004 3 00585 340 T4ACT573 Integrated Circuit Thru hole Pkg U 1005 3 00585 340 T4ACTS73 Integrated Circuit Thru hole Pkg U 1006 3 0055 1 341 128KX8 70 STATIC RAM I C U 1007 3 0055 1 341 128K X8 70 STATIC RAM I C Service Guide SR785 Dynamic Signal Analyzer 4 8 Parts Lists Video IO Board Assembly Ref No SRS Part No Value Component Description U 1008 3 00592 340 T4ACT299 Integrated Circuit Thru hole Pkg U 1009 3 00592 340 T4ACT299 Integrated Circuit Thru hole Pkg U 1010 3 00592 340 T4ACT299 Integrated Circuit Thru hole Pkg U 1011 3 00592 340 T4ACT299 Integrated Circuit Thru hole Pkg U 1012 3 00277 340 74HC11 Integrated Circuit Thru hole Pkg U 1013 3 00274 340 T4AC74 Integrated Circuit Thru hole Pkg U 1014 3 00274 340 7AAC74 Integrated Circuit Thru hole Pkg U 1016 3 00591 340 T4ACT04 Integrated Circuit Thru hole Pkg U 1017 3 00588 340 T4ACT08 Integrated Circuit Thru hole Pkg U 1101 3 00241 340 AD7528JN Integrated Circuit Thru hole Pkg U 1102 3 00087 340 LF347 Integrated Circuit Thru hole Pkg U 1103 3 00122 325 79L05 Transistor TO 92 Package U 1201
32. adjustment pots on the Analog board are towards the front Remove the small shield cover at the front of the Analog board Simply pull the shield up using the finger hole 5 The five adjustment pots are shown in Figure 8 3 Do not make any other adjustments Output Offset Analog Board VE chs m tes m eh Dues EE chs m e eh m z eh m e Ed m eh Ed E High Gain CMR m Ed ios HER eh m E cd rz High Gain Offset Low Gain Offset Low Gain CMR Figure 8 3 Analog Adjustments SR765 Dynamic Signal Analyzer Service Guide Service 3 25 6 Press the following keys to clear the internal offset calibrations and turn Auto Offset Off System lt Diagnostics gt lt Kill AutoOff gt 7 Press the following keys to set the input configuration and frequency span Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 0 Enter Chl Grounding lt Ch2 Grounding gt Select Ground Enter Chl Coupling Chl Coupling Select DC Enter Freq Span 1 6 Select KHz Enter Start Freq gt 0 Enter Marker Width Link Select Spot Enter 8 Connect a 50Q termination to the Ch1 Ch2 A input This shorts the input to ground so the analyzer s own DC offset is measured Rotate the knob so that the m
33. being careful to engage the slots which secure the front of the Disk card Replace the eight bezel screws Replace the handle and the pivot screws Replace the top lid and refasten the eight lid screws Replace the power cord Reset the unit by turning the power ON while holding down the backspace key Run the Disk test in the System lt Diagnostics gt menu SR785 Dynamic Signal Analyzer 3 24 Service Service Procedure J1 Adjusting the DC Offset and CMR 1 The DC Offset and CMR adjustments affect each other and must be done together This procedure requires a 50Q terminator A small but long slotted screwdriver is required to adjust the potentiometers 2 Reset the unit by turning the power ON while holding down the backspace key Let it warm up for at least an hour The adjustment procedure for the two channels is the same The procedure described below uses Channel 1 as the example To adjust Channel 2 press Active Display to switch to DisplayB Spectrum of Ch2 and when necessary adjust the Ch2 input parameters in the Input menu and make the input connections to the Ch2 A and B inputs Press Auto Scale B instead of Auto Scale A when necessary 3 Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the card cage cover by loosening the five screws which secure it 4 The
34. key Service Procedure G1 Replacing the Disk Drive Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom SR765 Dynamic Signal Analyzer Service Guide Service Guide 10 11 12 13 Service 3 23 Remove the front panel bezel by pulling it slowly off towards the front The keypad is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis The keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT Note the cable orientation and remove the cable from the Disk card Pull the Disk card straight out to remove it Insert the new Disk card Make sure that the card is in the plastic card guides under the CRT Do not force the card in if the card is not in the guides Push the card in until the connector is secure Reattach the keypad cable to the Disk card Replace the front panel bezel
35. provide a sine wave with an exact amplitude Connect the output of the frequency synthesizer to the phase lock input of the calibrator Connect the output of the AC calibrator to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Set the Synthesizer to Set the AC Calibrator to Function Sine Frequency 1 0 kHz Frequency 1 0 kHz Amplitude 6 3021 Vrms Amplitude 0 5 Vrms Voltage Off Offset off or OV Phase Lock On Sweep off Sense Internal Modulation none Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Window lt Window gt Select Flattop Enter Freq lt Span gt 1 6 Select kHz Enter lt Center Freq gt 1 Select kHz Enter Input lt Input Config gt lt Channel gt Select Both Enter Chl Coupling Select AC Enter Chl Input Range 2 2 Enter SR765 Dynamic Signal Analyzer 1 18 Performance Tests Average lt Averaging Type gt Select Linear Fix Len Enter lt Avgs gt 1 0 Enter Display Aveg gt Select RMS Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max 3 For each of the amplitudes listed below perform steps 3a through 3c AC Calibrator Amplitudes 6 3021 Vrms 1 1207 Vrms 141 09 mVrms 22 361 mVrms 3 544 mVrms a Set the AC calibrator to the am
36. the RS232 port on the rear panel NOT to the Printer port Use a tested cable Check that the SR785 is set to output data to the RS232 interface NOT the GPIB interface The output interface is set in the System Remote menu Check the RS232 setup in the System Remote menu Make sure that the proper baud rate word length and parity is selected Place a loop back connector on the RS232 port A loop back connector is a male DB25 connector with pins 2 and 3 connected together Perform the RS232 test in the System lt Diagnostics gt menu If the test fails proceed to Service Procedure D3 Video IO Board Replacement GPIB problems Check that the GPIB cable is securely fastened to the rear panel GPIB port Use a tested cable Check that the SR785 is set to output data to the GPIB interface NOT the RS232 interface The output interface is set in the System Remote menu Check the instrument GPIB address The address is set in the System lt Remote gt menu Proceed to Service Procedure D3 Video IO Board Replacement Printer problems Check that the printer cable is attached securely to the Printer port on the rear panel NOT the RS232 port Use a tested cable Check the Printer Type selected in the Output menu The SR785 can output to Epson compatible dot matrix printers or HP LaserJet InkJet compatible laser printers Make sure that the printer is On Line and has paper Proceed to Service Procedu
37. 00034 401 10K Resistor Carbon Film 1 4W 5 R 605 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 606 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 607 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 608 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 609 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R610 4 00241 407 787 Resistor Metal Film 1 8W 1 50PPM R 620 4 00480 407 80 6K Resistor Metal Film 1 8W 1 50PPM R 621 4 00164 407 20 0K Resistor Metal Film 1 8W 1 50PPM R 622 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 623 4 00032 401 100K Resistor Carbon Film 1 4W 5 R 624 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 625 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 626 4 00062 401 270 Resistor Carbon Film 1 4W 5 Service Guide SR785 Dynamic Signal Analyzer 4 18 Parts Lists DSP Board Assembly Ref No SRS Part No Value Component Description R 627 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 628 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 629 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 630 4 00048 401 2 2K Resistor Carbon Film 1 4W 5 R 631 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 632 4 00161 407 2 49K Resistor Metal Film 1 8W 1 50PPM R 633 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 635 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 636 4 00161 407 2 49K Resisto
38. 1 021 4 40X1 PP Screw Panhead Phillips Z0 0 00472 018 1 329631 2 Jam Nut Z0 0 00481 000 BUMPER CORD WRP Hardware Misc Z0 0 00500 000 554808 1 Hardware Misc Z0 0 00501 042 1 329632 2 Washer lock Z0 0 00502 000 CARD GUIDE 6 Hardware Misc Z0 0 00503 000 CARD GUIDE 2 5 Hardware Misc Z0 0 00505 064 10 32X1 4 Screw Socket Head Shoulder Z0 0 00506 000 HANDLES Hardware Misc Z0 0 00507 000 90MM 12V Hardware Misc Z0 0 00508 000 CARD GUIDE 5 Hardware Misc Z0 0 00517 000 BINDING POST Hardware Misc Z0 0 00519 027 4X3 16PP B Screw Sheet Metal Z0 0 00523 048 5 5 8 18 Wire 18 UL1015 Strip 3 8 x 3 8 No Tin Z0 0 00525 050 8 1 4 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00527 050 13 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00536 032 31894 Termination Z0 0 00598 031 4 40X1 3 8 M F Standoff SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 33 Analyzer Backplane Assembly Ref No SRS Part No Value Component Description Z0 0 00618 025 10 32X1 2 Screw Allen Head Z0 1 00073 120 INSL Connector BNC Z0 1 00120 113 3 PIN I8AWG OR Connector Amp MTA 156 Z0 1 00138 130 5 PIN SI Connector Male Z0 1 00141 171 5 PIN SIL Cable Assembly Ribbon Z0 1 00153 113 11 PIN ISAWG OR Connector Amp MTA 156 Z0 1 00246 130 20 PIN ELH SHR Connector Male Z0 1 00252 171 34 COND Cable Assembly Ribbon Z0 1 00253 171 20 COND Cable Assembly Ribbon Z0 1 00254 113 2 PIN 22AWG RD Con
39. 1 100 Resistor Carbon Film 1 4W 5 R 386 4 00330 407 1 65K Resistor Metal Film 1 8W 1 50PPM R 387 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 390 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 391 4 00738 407 442 Resistor Metal Film 1 8W 1 50PPM R 392 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 393 4 00738 407 442 Resistor Metal Film 1 8W 1 50PPM R 394 4 00696 407 43 2K Resistor Metal Film 1 8W 1 50PPM Service Guide SR785 Dynamic Signal Analyzer 4 28 Parts Lists Analog Input Board Assembly Ref No SRS Part No Value Component Description R 395 4 00210 407 9 09K Resistor Metal Film 1 8W 1 50PPM R 396 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 397 4 00158 407 2 00K Resistor Metal Film 1 8W 1 50PPM R 398 4 00210 407 9 09K Resistor Metal Film 1 8W 1 50PPM R 399 4 00696 407 43 2K Resistor Metal Film 1 8W 1 50PPM R 401 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 402 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 403 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 404 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 440 4 00154 407 150 Resistor Metal Film 1 8W 1 50PPM R 441 4 00154 407 150 Resistor Metal Film 1 8W 1 50PPM R 452 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 501 4 00107 402 10 Resistor Carbon Comp 1 2W 5 R 502 4 00107 402 10 Resistor Carbon Comp 1 2W 5 R51
40. 1 2RP Screw Roundhead Phillips Z0 0 00179 000 RIGHT FOOT Hardware Misc Z0 0 00180 000 LEFT FOOT Hardware Misc Z0 0 00181 020 6 32X1 4PF Screw Flathead Phillips Z0 0 00185 021 6 32X3 8PP Screw Panhead Phillips Z0 0 00187 021 4 40X 1 4PP Screw Panhead Phillips Z0 0 00195 020 6 32X3 8PF Screw Flathead Phillips Z0 0 00204 000 REAR FOOT Hardware Misc Z0 0 00209 021 4 40X3 8PP Screw Panhead Phillips Z0 0 00212 021 6 32X2PP Screw Panhead Phillips Z0 0 00248 026 10 32X3 8TRUSSP Screw Black All Types Z0 0 00249 021 6 32X1 1 2PP Screw Panhead Phillips Z0 0 00256 043 6 SHOULDER Washer nylon Z0 0 00259 021 4 40X1 2 PP Screw Panhead Phillips Z0 0 00280 050 9 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00308 021 4 40X 7 8PP Screw Panhead Phillips Z0 0 00327 050 8 18 WHITE Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00328 050 8 418 RED Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00329 050 8 18 BLACK Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00336 027 4X1 4PP B Screw Sheet Metal Z0 0 00351 029 4 40X1 4TRUSSPH Screw Truss Phillips Z0 0 00371 026 4 40X3 16PF Screw Black All Types Z0 0 00377 004 SR760 830 780 Knobs Z0 0 00378 004 CAP 760 830 780 Knobs Z0 0 00382 000 CARD GUIDE 4 5 Hardware Misc Z0 0 00390 024 1 72X1 4 Screw Slotted Z0 0 00391 010 1 72X5 32X3 64 Nut Hex Z0 0 00407 032 SOLDR SLV RG174 Termination Z0 0 00415 031 4 40X 1 2 M F Standoff Z0 0 00417 057 GROMMET STRIP Grommet Z0 0 0047
41. 1 4 00031 401 100 Resistor Carbon Film 1 4W 5 R512 4 00706 407 237 Resistor Metal Film 1 8W 1 50PPM R 513 4 00269 407 4 64K Resistor Metal Film 1 8W 1 50PPM R 521 4 00108 402 150 Resistor Carbon Comp 1 2W 5 R 522 4 00108 402 150 Resistor Carbon Comp 1 2W 5 R 541 4 00108 402 150 Resistor Carbon Comp 1 2W 5 R 542 4 00108 402 150 Resistor Carbon Comp 1 2W 5 R 543 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 544 4 00706 407 237 Resistor Metal Film 1 8W 1 50PPM R 545 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 546 4 00706 407 237 Resistor Metal Film 1 8W 1 50PPM R 601 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 602 4 00042 401 15K Resistor Carbon Film 1 4W 5 R 603 4 00042 401 15K Resistor Carbon Film 1 4W 5 R 604 4 00042 401 15K Resistor Carbon Film 1 4W 5 R 605 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 606 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 690 4 00054 401 200K Resistor Carbon Film 1 4W 5 R 701 4 00031 401 100 Resistor Carbon Film 1 4W 5 SO101 1 00173 150 8 PIN MACH Socket THRU HOLE SO102 1 00173 150 8 PIN MACH Socket THRU HOLE TP100 1 00143 101 TEST JACK Vertical Test Jack TP101 1 00143 101 TEST JACK Vertical Test Jack TP201 1 00143 101 TEST JACK Vertical Test Jack TP202 1 00143 101 TEST JACK Vertical Test Jack TP203 1 00143 101 TEST JACK Vertical Test Jack TP204 1 00143 101 TEST JACK Vertical Test Jack TP301 1 00143
42. 106 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 1107 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 1108 5 00218 529 120P Cap Monolythic Ceramic 50V 20 Z5U C 1109 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C1110 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1201 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL C 1202 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL C 1203 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL C 1204 5 00316 512 027U Cap Stacked Metal Film 50V 5 40 85c C 1205 5 00054 512 047U Cap Stacked Metal Film 50V 5 40 85c C 1206 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL C 1303 5 00012 501 330P Capacitor Ceramic Disc 50V 1096 SL C 1304 5 00012 501 330P Capacitor Ceramic Disc 50V 1096 SL C 1305 5 00178 501 62P Capacitor Ceramic Disc 50V 1096 SL C 1306 5 00178 501 62P Capacitor Ceramic Disc 50V 1096 SL C 1401 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1402 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1403 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1404 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1405 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1406 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1407 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1408 5 00262 548 01U AXIAL Capacitor Ceramic
43. 148 Diode Service Guide SR785 Dynamic Signal Analyzer 4 24 Parts Lists Analog Input Board Assembly Ref No SRS Part No Value Component Description D 120 3 00457 301 1N5241B Diode D 201 3 00004 301 1N4148 Diode D 202 3 00004 301 1N4148 Diode D 301 3 00004 301 1N4148 Diode D 302 3 00004 301 1N4148 Diode D 303 3 00004 301 1N4148 Diode D501 3 00004 301 1N4148 Diode D 502 3 00004 301 1N4148 Diode D511 3 00004 301 1N4148 Diode J101 1 00241 141 RT ANGLE JACK SMB Connector J 102 1 00241 141 RT ANGLE JACK SMB Connector J701 1 00234 109 96 PIN RT ANGLE DIN Connector Male K 101 3 00240 335 BS 211 DC12 GF Relay K 102 3 00240 335 BS 211 DC12 GF Relay K 103 3 00239 335 HS 212 12 Relay K 104 3 00239 335 HS 212 12 Relay K 105 3 00239 335 HS 212 12 Relay K 106 3 00239 335 HS 212 12 Relay K 107 3 00240 335 BS 211 DC12 GF Relay K 108 3 00239 335 HS 212 12 Relay K 201 3 00240 335 BS 211 DC12 GF Relay K 202 3 00240 335 BS 211 DC12 GF Relay K 203 3 00240 335 BS 211 DC12 GF Relay K 204 3 00240 335 BS 211 DC12 GF Relay K 301 3 00240 335 BS 211 DC12 GF Relay N 102 4 00244 421 10KX4 Res Network SIP 1 4W 2 Isolated N 103 4 00690 421 3 3KX4 Res Network SIP 1 4W 2 Isolated N 210 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common N 211 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common N 212 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common N 213 4 00252 425 100X5
44. 19 529 01U Cap Monolythic Ceramic 50V 20 Z5U C8C 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C9 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 10C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C11C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 12 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 13C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 14C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 15 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 16C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C17C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 18C 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 19C 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 20C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C21 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C22 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U D 1B 3 00610 303 GREEN RT ANGLE LED T1 Package J1C 1 00233 120 RT ANGLE Connector BNC J2C 1 00233 120 RT ANGLE Connector BNC J3C 1 00233 120 RT ANGLE Connector BNC J4C 1 00233 120 RT ANGLE Connector BNC J5C 1 00233 120 RT ANGLE Connector BNC J6C 1 00233 120 RT ANGLE Connector BNC J 10C 1 00235 108 96 PIN VERTICAL DIN Connector Female J11C 1 00235 108 96 PIN VERTICAL DIN Connector Female J 20C 1 00235 108 96 PIN VERTICAL DIN Connector Female J 30C 1 00224 141 STRAIGHT PLUG SMB Con
45. 20 Z5U AX C 99 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 992 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 993 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX Service Guide SR785 Dynamic Signal Analyzer 4 16 Parts Lists DSP Board Assembly Ref No SRS Part No Value Component Description C 994 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 995 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 996 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 997 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 998 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 999 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX D 501 3 00004 301 1N4148 Diode D 502 3 00004 301 1N4148 Diode D601 3 00204 301 1N5230 Diode D 602 3 00204 301 1N5230 Diode D 603 3 00004 301 1N4148 Diode D 604 3 00004 301 1N4148 Diode D 605 3 00204 301 1N5230 Diode D 606 3 00204 301 1N5230 Diode D 607 3 00004 301 1N4148 Diode D 608 3 00004 301 1N4148 Diode D 660 3 00004 301 1N4148 Diode D 661 3 00004 301 1N4148 Diode J 201 1 00239 135 72 PIN SIMM Connector Card Edge J 202 1 00239 135 72 PIN SIMM Connector Card Edge J 203 1 00239 135 72 PIN SIMM Connector Card Edge J 204 1 00239 135 72 PIN SIMM Connector Card Edge J 501 1 00241 141 RT ANGLE JACK SMB Connector J 601 1 00241 141
46. 3 20 dBV 14dBV 99 881 mVrms 17 20 dBV 4 dBV 10 dBV 22 dBV 34 dBV Input Range 0 7934 Vrms 1 5830 Vrms 6 3021 Vrms 25 089 Vrms Flatness relative to 1 kHz Frequency 14dBV 14dBV 14dBV 14dBV 24 kHz 48 kHz 76 kHz 99 kHz SR765 Dynamic Signal Analyzer 0 80 dBV 6 80 dBV 18 80 dBV 30 80 dBV Lower Limit DispA Chl DispB Ch2 48 80 dBV 40 80 dBV 32 80 dBV 16 80 dBV 1 20 dBV 7 20 dBV 19 20 dBV 31 20 dBV Upper Limit 17 20 dBV 17 20 dBV 17 20 dBV 17 20 dBV 16 80 dBV 16 80 dBV 16 80 dBV 16 80 dBV SR785 Performance Test Record 4 Amplitude Accuracy and Flatness Continued Flatness relative to 1 kHz Input Range Frequency 22 dBV 24 kHz 22 dBV 48 kHz 22 dBV 72 kHz 22 dBV 96 kHz Amplitude Linearity Input Range Calibrator Ampl Lower Limit DispA Chl DispB Ch2 Performance Tests 1 33 Page 2 of 3 Upper Limit 18 80 dBV 18 80 dBV 18 80 dBV 18 80 dBV Lower Limit DispA Chl DispB Ch2 19 20 dBV 19 20 dBV 19 20 dBV 19 20 dBV Upper Limit 22 dBV 6 3021 Vrms 1 1207 Vrms 141 09 mVrms 22 361 mVrms 3 544 mVrms Anti Alias Filter Attenuation Frequency Accuracy 18 80 dBV 3 80 dBV 14 20 dBV 30 20 dBV 46 20 dBV Input Frequency DispA Chl DispB Ch2 19 20 dBV 4 20 dBV 13 80 dBV 29 80 dBV 45 80 dBV Upper Limit 160 144 kHz Input Frequency Lower Limit 96 000 kHz Phase
47. 410 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C411 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C414 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 420 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C421 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 422 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 423 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 424 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 425 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 426 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 427 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 428 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 429 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 440 5 00287 562 22P Cap NPO Monolitic Ceramic 50v 5 Ra C 441 5 00287 562 22P Cap NPO Monolitic Ceramic 50v 596 Ra C 456 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C501 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C 502 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C 503 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 504 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 505 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 506 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C511 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C512 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C513 5 00100 517 2 2U Capacit
48. 5 Dynamic Signal Analyzer 2 16 Circuit Description The two gain stages are identical inverting amplifiers Each has selectable gain of 10 dB 0 dB 10 dB or 20 dB To achieve the desired gain the front end attenuator and amplifier and these two gain stages are cascaded together The signal path always includes the same number of amplifiers The resistive ladder attenuator R211 R216 provides attenuation from OdB to 10 dB in 2 dB steps This improves the gain resolution U206 is the buffered amplifier output Comparators U220 and U392 detect overload and half scale amplifier output based upon the A D converter reference voltage Anti Aliasing Filter To prevent aliasing the input signal passes through a low pass filter so that all frequency components greater than half the sampling frequency are attenuated by at least 96 dB This is accomplished with an 8 zero 9 pole elliptical low pass filter U230 U233 The pass band of this filter is DC to 102 4 kHz with a ripple of 0 5 dB The stopband begins at 156 KHz Stopband attenuation is nominally 100 dB U234A follows the anti aliasing filter to sum the DC offset correction from DAC U361 with the signal A second 51 2 kHz anti aliasing filter U240 U243 is used for two channel octave measurements Relays K202 K203 and K204 select an anti aliasing filter or bypasses the filters altogether The filter output is buffered by U244A and U244B to the trigger circuit on the DSP board A Weig
49. 5 Dynamic Signal Analyzer Service Guide Parts Lists 4 25 Analog Input Board Assembly Ref No SRS Part No Value Component Description R 106 4 005 15 407 31 6K Resistor Metal Film 1 8W 1 50PPM R 107 4 00580 407 475 Resistor Metal Film 1 8W 1 50PPM R 108 4 00580 407 475 Resistor Metal Film 1 8W 1 50PPM R 109 4 00544 407 165 Resistor Metal Film 1 8W 1 50PPM R 110 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM R111 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM R112 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM R 113 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM R 114 4 00145 407 110 Resistor Metal Film 1 8W 1 50PPM R 115 4 00145 407 110 Resistor Metal Film 1 8W 1 SOPPM R 116 4 00217 408 1 000K Resistor Metal Film 1 8W 0 1 25ppm R 117 4 00217 408 1 000K Resistor Metal Film 1 8W 0 1 25ppm R 118 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM R 119 4 00375 407 348 Resistor Metal Film 1 8W 1 50PPM R 120 4 00375 407 348 Resistor Metal Film 1 8W 1 50PPM R 121 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM R 122 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM R 123 4 00203 407 75 0K Resistor Metal Film 1 8W 1 SOPPM R 124 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM R 125 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 126 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 127 4 00192 407 49 9K Resistor Metal Fil
50. 501 6 00137 601 15MH Inductor T 601 6 00009 610 T1 1 X65 Transformer T 611 6 00009 610 T1 1 X65 Transformer T 612 6 00009 610 T1 1 X65 Transformer TP502 1 00143 101 TEST JACK Vertical Test Jack TP503 1 00143 101 TEST JACK Vertical Test Jack TP506 1 00143 101 TEST JACK Vertical Test Jack TP507 1 00143 101 TEST JACK Vertical Test Jack TP601 1 00143 101 TEST JACK Vertical Test Jack TP602 1 00143 101 TEST JACK Vertical Test Jack TP603 1 00143 101 TEST JACK Vertical Test Jack TP604 1 00143 101 TEST JACK Vertical Test Jack TP901 1 00143 101 TEST JACK Vertical Test Jack TP902 1 00143 101 TEST JACK Vertical Test Jack TP903 1 00143 101 TEST JACK Vertical Test Jack U 101 3 00577 340 ADSP21020KG 133 Integrated Circuit Thru hole Pkg U 102 6 00177 621 33 333 MHZ Crystal Oscillator U 301 3 00859 343 SR785 U301 GAL PAL I C U 302 3 00597 340 CY7C433 25 Integrated Circuit Thru hole Pkg U 303 3 00597 340 CY7C433 25 Integrated Circuit Thru hole Pkg U 304 3 00597 340 CY7C433 25 Integrated Circuit Thru hole Pkg U 401 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 19 DSP Board Assembly Ref No SRS Part No Value Component Description U 402 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 403 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 404 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 405 3 00265 340 74HC
51. 517 2 2U Capacitor Tantalum 35V 20 Rad C 663 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C701 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad C 702 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 703 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 704 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 705 5 00177 501 30P Capacitor Ceramic Disc 50V 10 SL C 706 5 00177 501 30P Capacitor Ceramic Disc 50V 10 SL C 901 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C 902 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C 903 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 904 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 905 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 906 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 907 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad C 908 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 920 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C921 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 922 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 923 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 924 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 925 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 926 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 927 5 00225 548 1U AXIAL Capacit
52. 595 Integrated Circuit Thru hole Pkg U 406 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 407 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 408 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 409 3 00488 340 74HC597 Integrated Circuit Thru hole Pkg U 410 3 00488 340 74HC597 Integrated Circuit Thru hole Pkg U 411 3 00350 340 74ALS04 Integrated Circuit Thru hole Pkg U 501 3 00531 340 AD766JN Integrated Circuit Thru hole Pkg U 502 3 00532 340 AD744 Integrated Circuit Thru hole Pkg U 505 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 506 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 507 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 508 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 509 3 00241 340 AD7528JN Integrated Circuit Thru hole Pkg U 510 3 00371 340 DG444 Integrated Circuit Thru hole Pkg U 511 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 512 3 00383 340 LM6321 Integrated Circuit Thru hole Pkg U 513 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 520 3 00117 325 78L12 Transistor TO 92 Package U 521 3 00123 325 79L12 Transistor TO 92 Package U 530 3 00089 340 LF357 Integrated Circuit Thru hole Pkg U 601 3 00461 340 OPA2604 Integrated Circuit Thru hole Pkg U 602 3 00262 340 74HC86 Integrated Circuit Thru hole Pkg U 603 3 0021 1 340 LT1016 Integrated Circuit Thru hole Pkg U 604 3 00461 340 OPA2604 Integrated Circuit Thru h
53. 5U C 556 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C557 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 558 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C559 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 560 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 561 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 562 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 563 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 564 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 565 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 566 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 567 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C570 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C571 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 572 5 00034 526 100U Capacitor Electrolytic 35V 20 Rad C 573 5 00034 526 100U Capacitor Electrolytic 35V 20 Rad C 574 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C575 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 576 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C577 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C601 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 602 5 00200 532 470P Capacitor Ceramic Disc 50V 10 NPO Service Guide SR785 Dynamic Signal Analyzer 4 14 Parts Lists DSP Board Assembly Ref No SRS Part No Val
54. 62 714 SR780 39 Extrusion Z0 7 00673 721 SR780 44 Machined Part Z0 7 00674 721 SR780 46 Machined Part Z0 7 00675 721 SR780 47 Machined Part Z0 7 00723 720 SR780 48 Fabricated Part Z0 7 00800 709 SR785 Lexan Overlay Z0 8 00045 840 9 Z AXIS CRT Display Z0 9 00267 917 GENERIC Product Labels Z0 9 008 15 924 DBL SIDED 1 2 Tape All types Service Guide SR785 Dynamic Signal Analyzer 4 34 Parts Lists Demo Filter Board Parts List Demo Filter Board Assembly Ref No SRS Part No Value Component Description CI 5 00149 545 01U Capacitor Monolythic Ceramic COG 146 C2 5 00149 545 01U Capacitor Monolythic Ceramic COG 1 C3 5 00149 545 01U Capacitor Monolythic Ceramic COG 1 C4 5 00149 545 01U Capacitor Monolythic Ceramic COG 1 PCI 7 00672 701 SR780 DEMO Printed Circuit Board RI 4 00600 407 15 8K Resistor Metal Film 1 8W 1 50PPM R2 4 00600 407 15 8K Resistor Metal Film 1 8W 1 50PPM R3 4 00303 407 7 87K Resistor Metal Film 1 8W 1 50PPM Z0 0 00196 052 1 1 2 X 22 Wire 22 UL1007 Z0 1 00003 120 BNC Connector BNC SR785 Dynamic Signal Analyzer Service Guide Miscellaneous Parts List Parts Lists 4 35 Miscellaneous Assembly Ref No SRS Part No Value Component Description U 301 3 00552 342 27C010 70DC EPROM PROM I C U 302 3 00552 342 27C010 70DC EPROM PROM I C U 303 3 00552 342 27C010 70DC EPROM PROM I C U 304 3 00552 342 27C010 70
55. 766 Since the DAC is clocked synchronously with the A D converters the source is synchronous with the input sampling The output of U501 is buffered by U502 AD744 U505 U507 form an elliptic anti aliasing filter to remove high frequency components K501 selects the anti aliasing filter output or the pink noise filter output U530 as the source U5094 is used as an 8 bit attenuator and U510 is a divide by 10 or 100 attenuator U512 is a high current output buffer which provides the low output impedance Interface To CPU The CPU interface provides the communication pathway between the DSP board and the main CPU board All signal interconnections are made via the 120 pin connector J902 U801 U803 are buffers for the address and data bus connections These buffer chips are enabled only when the CPU board is writing to the DSP board This is signaled by PCS4 from the 80C186 This helps isolate the activity on the CPU board from affecting circuitry on the DSP board U808 and U809 are simple latches used to hold configuration data for the DSP board U805 is a decoder which generates the chip selects and strobes needed by the DSP board U810 is a serial EEPROM which holds the calibration data required by the source and trigger circuits SR765 Dynamic Signal Analyzer Service Guide Circuit Description 2 15 Analog Input Boards This section covers schematics A780 1 through A780 7 in Chapter 5 The Analog Input boards provide the very important lin
56. A Auto Scale B Link Marker Max The Y value of the markers should both read 17 0 dB 0 15 dB d Set the AC calibrator and frequency synthesizer to the frequency in the table e Press Frequency lt Center Freq gt Enter the signal frequency Start Reset Wait for the average to settle Link Marker Max f Record the marker Y reading for both displays Repeat steps 4d and 4e for all of the frequencies listed 5 Now repeat the frequency response measurements at a different input range a Set the AC calibrator to 1 kHz and an amplitude of 6 3021 Vrms b Set the frequency synthesizer to 1 kHz c Press Freq lt Center Freq gt 1 lt kHz gt Input Chl Input Range 2 2 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max The Y value of the marker should now read 19 0 dB 0 15 dB SR765 Dynamic Signal Analyzer 1 16 Performance Tests d Repeat steps 4d through 4f above 6 This completes the amplitude accuracy and frequency response test Enter the results of this test in the test record at the end of this section SR785 Dynamic Signal Analyzer Performance Tests 1 17 5 Amplitude Linearity This test measures the amplitude linearity This tests how accurately the analyzer measures a signal smaller than full scale Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to
57. AX C 947 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 948 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 949 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 950 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 951 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 952 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 953 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 954 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 955 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 956 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 957 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 958 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 959 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 960 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 961 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 962 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 963 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 964 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 965 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 966 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 967 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 968 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20
58. Angle PC Female JP13A 1 00242 130 20 PIN ELH VERT Connector Male JP20A 1 00237 108 120 PIN VERTICA DIN Connector Female JP21A 1 00119 116 3 PIN WHITE Header Amp MTA 156 JP22A 1 00272 130 34 PIN DI Connector Male JP23A 1 00152 116 11 PIN WHITE Header Amp MTA 156 JP24A 1 00250 116 2 PIN WHITE Header Amp MTA 156 Z0A 6 00076 600 2 SPKR Misc Components Service Guide SR785 Dynamic Signal Analyzer 4 12 Parts Lists Disk Card Parts List This section covers schematic MBKPL 24 in Chapter 5 Disk Card Assembly Ref No SRS Part No Value Component Description C1B 5 00192 542 22U MIN Cap Mini Electrolytic 50V 20 Radial JP1B 1 00234 109 96 PIN RT ANGLE DIN Connector Male JP2B 1 00272 130 34 PIN DI Connector Male JP3B 1 00116 130 4 PIN DI DISK Connector Male JPAB 1 00113 100 DIN 5 Connector Misc Z 0B 8 00034 850 FLOPPY Disk Drive SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 13 DSP Board Parts List This section covers schematics D785 1 through D785 11 in Chapter 5 DSP Board Assembly Ref No SRS Part No Value Component Description C 101 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 102 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 103 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 301 5 00177 501 30P Capacitor Ceramic Disc 50V 10 SL C 501 5 00100 517 2 2U Capacitor Tantalum 35V
59. DC EPROM PROM I C U 305 3 00552 342 27C010 70DC EPROM PROM I C U 306 3 00552 342 27C010 70DC EPROM PROM I C U 801 3 00639 342 27C020 120 EPROM PROM I C U 802 3 00639 342 27C020 120 EPROM PROM I C Z0 0 00187 021 4 40X 1 4PP Screw Panhead Phillips Z0 3 00599 350 8MB 2X32 60 SIMM Dynamic Ram Z0 3 00612 350 4MSX32 80 SIMM Dynamic Ram Z0 3 00613 350 32MB 8X32 60 2K SIMM Dynamic Ram Z0 7 00405 720 SR770 11 Fabricated Part Z0 7 00542 720 SR780 8 Fabricated Part Z0 7 00543 720 SR780 9 Fabricated Part Z0 7 00548 720 SR780 15 Fabricated Part Z0 7 00620 720 SR780 26 Fabricated Part Z0 7 0063 1 720 SR780 25 Fabricated Part Service Guide SR785 Dynamic Signal Analyzer 5 1 Chapter 5 Schematic Diagrams In This Chapter CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Board MKEY 1 DSP Board D780 1 through D780 9 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 Demo Filter F780 1 Service Guide SR780 Network Signal Analyzer 5 2 Schematic Diagrams SR760 Network Signal Analyzer Service Guide
60. Input Config Ch2 Input Mode Select A B Enter Start Reset Wait for the average to finish 6 Record the marker Y reading This is the Ch2 CMRR in dB at 1 KHz 7 This completes the CMRR measurement test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer Performance Tests 1 13 4 Amplitude Accuracy and Flatness This test measures the input amplitude accuracy and frequency response Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to provide a sine wave with an exact amplitude Connect the output of the frequency synthesizer to the phase lock input of the calibrator Connect the output of the AC calibrator to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Set the Synthesizer to Set the AC Calibrator to Function Sine Frequency 1 0 kHz Frequency 1 0 kHz Amplitude 0 707 mVrms Amplitude 0 5 Vrms Voltage Off Offset off or OV Phase Lock On Sweep off Sense Internal Modulation none Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Window lt Window gt Select Flattop Enter Freq lt Span gt 1 6 Select kHz Enter lt Center Freq gt 1 Select kHz Enter Input lt Input Config gt lt Channel gt Select Both Enter Chl Coup
61. Knob Check CPU Board Replacement Battery Check Video IO Board Replacement iii 1 3 1 7 1 9 1 11 1 13 1 17 1 19 1 21 1 23 1 25 1 29 1 31 1 32 2 3 2 5 2 8 2 10 2 12 2 15 3 3 3 4 3 8 3 10 3 10 3 10 3 10 3 11 3 13 3 14 3 14 3 15 3 16 3 17 3 17 SR785 Dynamic Signal Analyzer iv Contents DSP Board Replacement Analog Board Replacement Checking the Analog Inputs Checking the Amplitude Checking the Trigger Checking the Source DSP Memory Module Replacement Replacing the Disk Drive Adjusting the DC Offset and CMR Chapter 4 Parts List CPU Board Video IO Board Power Supply Board System Backplane Disk Card DSP Board Analog Input Board Analyzer Backplane Chapter 5 Schematic Diagrams Schematic Diagram List CPU Board Video IO Board Power Supply Board System Backplane Disk Card Keypad Board DSP Board Analog Input Board Analyzer Backplane Demo Filter SR785 Dynamic Signal Analyzer 3 18 3 18 3 19 3 20 3 20 3 21 3 21 3 22 3 24 4 3 4 6 4 9 4 11 4 12 4 13 4 20 4 29 5 3 MCPU 1 MVID 1 MPWR 1 MBKPL 1 MBKPL 24 MKEY 1 D785 1 A780 1 M780 1 F780 1 Service Guide Table of Figures Service Guide Figure 3 1 System Components Figure 3 2 Analyzer Components Figure 3 1 System Components Figure 3 2 Analyzer Components Figure 3 3 Analog Adjustments 3 3 3 8 3 9 3 24 SR785 Dynamic Signal Analyzer vi SR785 Dynamic Signal Analyzer Serv
62. Marker Width Link Select Wide Enter Seeks Link Select Mean Enter Start Reset Wait for the average to finish Link Marker Max 3 Record the marker Y readings for both displays 4 Press Freq lt Start Freq gt 5 1 2 Select kHz Enter Start Reset Wait for the average to finish Link Marker Max 5 Record the marker Y readings for both displays 6 Press Display Options Display Setup lt Units gt lt Pk Units gt Select pk Enter lt PSD Units gt Select Off Enter Marker lt Seeks gt Select Max Enter 7 For each of the spans listed below perform steps 7a through 7c SR785 Dynamic Signal Analyzer Center Frequency 230 Hz 500 Hz 1 kHz 5 kHz 10 kHz 25 kHz 50 kHz 75 kHz 101 kHz a Press Freq lt Span gt Enter the span from the table lt Center Freq gt Enter the center frequency from the table Start Reset b Wait for the average to finish 20 averages Link Marker Max c Record the marker Y readings for both displays Span 400 Hz 400 Hz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz Performance Tests 1 27 8 This completes the noise and spurious signal test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer 1 28 Performance Tests SR785 Dynamic Signal Analyzer Performance Tests 1 29 10 Sine Source This tes
63. Move the cable from the old pot to the new pot maintaining the correct cable orientation Place the new pot shaft into the hole in the bezel and secure the shaft with the mounting nut Replace the plastic knob on the shaft and tighten the nut at the center Replace the knob cover Replace the front panel bezel being careful to engage the slots which secure the front of the Disk card Replace the eight bezel screws Replace the handle and the pivot screws If the knob still does not function then the problem may be on the CPU board The keypad circuit board contains no active circuitry and is very unlikely to fail To replace the CPU board follow Procedure D1 CPU Board Replacement Replace the top lid and refasten the eight lid screws Service Procedure D1 CPU Board Replacement 1 2 Before replacing the CPU board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place See Figure 8 1 to locate the CPU board
64. N4148 Diode D11 3 00004 301 1N4148 Diode D 12 3 00004 301 1N4148 Diode D 13 3 00011 303 RED LED T1 Package D 14 3 00004 301 1N4148 Diode D 15 3 00004 301 1N4148 Diode D 16 3 00004 301 1N4148 Diode D 17 3 00004 301 1N4148 Diode JP1 1 00236 109 120 PIN RT ANGL DIN Connector Male JP2 1 00039 116 5 PIN WHITE Header Amp MTA 156 JP3 1 00114 116 10 PIN WHITE Header Amp MTA 156 NI 4 00244 421 10KX4 Res Network SIP 1 4W 2 Isolated PC1 7 00526 701 SR780 P S Printed Circuit Board R10 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 Service Guide SR785 Dynamic Signal Analyzer 4 10 Parts Lists Power Supply Board Assembly Ref No SRS Part No Value Component Description R11 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R12 4 00522 407 243 Resistor Metal Film 1 8W 1 50PPM R 13 4 00444 407 3 65K Resistor Metal Film 1 8W 1 50PPM R 14 4 00522 407 243 Resistor Metal Film 1 8W 1 50PPM R15 4 00444 407 3 65K Resistor Metal Film 1 8W 1 50PPM R 20 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R21 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R22 4 00522 407 243 Resistor Metal Film 1 8W 1 50PPM R23 4 00444 407 3 65K Resistor Metal Film 1 8W 1 50PPM R24 4 00522 407 243 Resistor Metal Film 1 8W 1 50PPM R25 4 00444 407 3 65K Resistor Metal Film 1 8W 1 50PPM R31 4 00034 401 10K Resistor Carbon Film 1 4W 596 R32 4 00522 407 243 Resistor Metal Film 1 8W 1
65. Procedure A2 Power Supply Check Service Procedure B1 Replacing the CRT Service Procedure B2 CRT Check Service Procedure C1 Keypad Check Service Procedure C2 Knob Check Service Procedure D1 CPU Board Replacement Service Procedure D2 Battery Check Service Procedure D3 Video IO Board Replacement Service Procedure F1 DSP Board Replacement Service Procedure F2 Analog Board Replacement Service Procedure F3 Checking the Analog Inputs Service Procedure F4 Checking the Amplitude Service Procedure F5 Checking the Trigger Service Procedure F6 Checking the Source Service Procedure F7 DSP Memory Module Replacement Service Procedure G1 Replacing the Disk Drive Service Procedure J1 Adjusting the DC Offset and CMR Service Guide 3 3 3 3 3 3 3 3 3 8 3 8 3 9 3 9 3 10 3 10 3 10 3 10 3 11 3 13 3 14 3 14 3 15 3 16 3 17 3 17 3 18 3 18 3 19 3 20 3 20 3 21 3 21 3 22 3 24 SR785 Dynamic Signal Analyzer 3 2 Service SR785 Dynamic Signal Analyzer Service Guide Service 3 3 Before Proceeding With Service Warranty Service CAUTION Reset A Calibration Service Guide For warranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Do not attempt any service without first contacting Stanford Research Systems or an authorized representative Replacement parts boards and assemblies are available only from Stanford Research Syst
66. Resistor Network SIP 1 4W 2 Common N 301 4 00675 456 2 000KX7 Res Network DIP 1 4W 0 1 N 402 4 00463 421 82X4 Res Network SIP 1 4W 2 Isolated N 601 4 00243 420 1 0KX8 Resistor Network DIP 1 4W 2 8 Ind N 602 4 00254 421 1 0KX3 Res Network SIP 1 4W 2 Isolated P 101 4 00354 445 20 Pot Multi Turn Side Adjust P 102 4 00015 445 100K Pot Multi Turn Side Adjust P 103 4 00730 445 100 Pot Multi Turn Side Adjust P 104 4 00015 445 100K Pot Multi Turn Side Adjust P 201 4 00015 445 100K Pot Multi Turn Side Adjust P 301 4 00731 445 200 Pot Multi Turn Side Adjust P 310 4 00015 445 100K Pot Multi Turn Side Adjust P311 4 00760 445 500 Pot Multi Turn Side Adjust P 360 4 0027 1 445 2 0K Pot Multi Turn Side Adjust PCI 7 00616 701 SR780 ANALOG Printed Circuit Board Q 101 3 00022 325 2N3906 Transistor TO 92 Package Q 102 3 00021 325 2N3904 Transistor TO 92 Package Q 201 3 00021 325 2N3904 Transistor TO 92 Package Q 202 3 00021 325 2N3904 Transistor TO 92 Package Q 301 3 00021 325 2N3904 Transistor TO 92 Package Q 601 3 00021 325 2N3904 Transistor TO 92 Package R 100 4 00071 401 33 Resistor Carbon Film 1 4W 596 R 101 4 00616 453 49 9 Resistor 2W 1 R 102 4 00071 401 33 Resistor Carbon Film 1 4W 5 R 103 4 00593 408 965 0K Resistor Metal Film 1 8W 0 1 25ppm R 104 4 005 15 407 31 6K Resistor Metal Film 1 8W 1 50PPM R 105 4 00593 408 965 0K Resistor Metal Film 1 8W 0 1 25ppm SR78
67. SR765 Dynamic Signal Analyzer Service Guide Service 3 5 Symptoms Power On DSP memory If Data Memory fails proceed to Service Procedure F7 check fails Replacing DSP Memory Modules Use System Show e If Program Memory fails proceed to Service Procedure Versions to teview test F7 Replacing DSP Memory Modules results e If DRAM Errors are detected proceed to Service Procedure F7 Replacing DSP Memory Modules e If the DSP Cal ROM is not OK proceed to Service Procedure F1 DSP Board Replacement Proceed to Service Procedure F1 DSP Board Replacement Proceed to Service Procedure F6 Checking the Source DSP memory upgrade To upgrade the DSP DRAM to 4M or 8M proceed to Service Procedure F7 Replacing DSP Memory Modules Power On Analog e If the Chl or Ch2 Analog Cal ROM is not OK proceed memory check fails to Service Procedure F2 Analog Board Replacement Use System Show Version to review test results Disk Drive problems Check that your disk is DS DD or DS HD Try a new disk Check that the disk write protect tab is closed Perform the disk drive test in the System lt Diagnostics gt menu Proceed to Service Procedure G1 Disk Drive Replacement If there is still a problem proceed to Service Procedure D3 Video IO Board Replacement Service Guide SR785 Dynamic Signal Analyzer 3 6 Service RS232 problems Check that the RS232 cable is attached securely to
68. Service Guide Model SR785 Dynamic Signal Analyzer S RS Stanford Research Systems 1290 D Reamwood Avenue Sunnyvale CA 94089 U S A Phone 408 744 9040 Fax 408 744 9049 Email info thinkSRS com www thinkSRS com Copyright 1995 1996 1998 Stanford Research Systems Inc All Rights Reserved Revision 1 2 October 2004 Certification Stanford Research Systems certifies that this product met its published specifications at the time of shipment Stanford Research Systems further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology NIST Warranty This Stanford Research Systems product is warranted against defects in materials and workmanship for a period of one 1 year from the date of shipment Service For watranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this document is subject to change without notice Copyright Stanford Research Systems Inc 1998 All rights reserved Stanford Research Systems Inc 1290 D Reamwood Avenue Sunnyvale California 94089 Printed in U S A SR785 Dynamic Signal Analyzer Service Guide Safety and Preparation For Use WARNING Dangerous voltages capable of causing injury or death are present in this instrument
69. Use extreme caution whenever the instrument cover is removed Do not remove the cover while the unit is plugged into a live outlet Caution This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR set for the wrong AC line voltage or if the wrong fuse is installed Line Voltage Selection The SR785 operates from a 100V 120V 220V or 240V nominal AC power source having a line frequency of 50 or 60 Hz Before connecting the power cord to a power source verify that the LINE VOLTAGE SELECTOR card located in the rear panel fuse holder is set so that the correct AC input voltage value is visible Conversion to other AC input voltages requires a change in the fuse holder voltage card position and fuse value Disconnect the power cord open the fuse holder cover door and rotate the fuse pull lever to remove the fuse Remove the small printed circuit board and select the operating voltage by orienting the printed circuit board so that the desired voltage is visible when pushed firmly into its slot Rotate the fuse pull lever back into its normal position and insert the correct fuse into the fuse holder Line Fuse Verify that the correct line fuse is installed before connecting the line cord For 100V 120V use a 1 5 Amp fuse For 220V 240V use a 3 4 Amp fuse Line Cord The SR785 has a detachable three wire power cord for connection to the power source and to a protective ground The exposed metal parts of the instrument are connect
70. agnostics gt menu If the test passes then the keypad is OK If the test fails or cannot be completed then proceed 2 Turn the power OFF Remove the power cord from the power A entry module 3 Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards 4 Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly 5 Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom 6 Remove the front panel bezel by pulling it slowly off towards the front The keypad is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis 7 The keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT The cable attaches to the SR765 Dynamic Signal Analyzer Service Guide 10 11 13 Service 3 15 back of the keypad board on the front panel Make sure that the cable is firmly attached at both ends and that the cable is not damaged Check that the ground wire is attached firmly to the chassis and to the keypad board Push the Disk card inward to make sure that it is seated properly The keypad sig
71. ain processor CPU video display external interfaces power supply and front panel The analyzer section contains the digital signal processor DSP source output and analog inputs System Components The system section components are located in the left half of the chassis behind and below the CRT video display The card cage behind the CRT contains the power supply main CPU card and the video IO card The cards are interconnected by a backplane board under the card cage The disk drive is mounted to a small board beneath the CRT This card can be removed from the front The keypad connects to the disk board at the front of the chassis Figure 7 1 System Components Chsssis Top View CPU S Power Supply System SS TT Disk Card 7 Disk Drive Front Analyzer Components The analyzer section is in the right half of the chassis directly behind the keypad A card cage contains the DSP board and two identical analog input boards The analyzer boards are interconnected by a backplane board under the card cage This backplane extends all Service Guide SR785 Dynamic Signal Analyzer 2 4 Circuit Description the way to the front panel BNC connectors The analyzer backplane connects to the system backplane via two short cables at the center of the chassis just behind the CRT Figure 7 2 Analyzer Components Chassis Top View DSP Board Chl Analog Input Board Ch2 Analog Input Board
72. allel to serial converters The video data is shifted out at 19 59 MHz and synchronized by U1013 U1014A synchronizes the Display Enable to disable the video data except during active display times The display consists of two layers or planes Data on the front plane appears in front of data on the rear plane Each pixel requires two bits of information The even bit is drawn on the front plane and the odd bit is drawn on the rear plane The even bit disables the odd bit which puts it in front U1012 handles the layering logic The display planes make it simple to draw a graph in front of a grid The two display planes each have their own display brightness This gives the display a three dimensional appearance Current sources Q1101 and Q1102 set the brightness for the front and rear planes U1101 is a dual DAC which programs the two current sources Disk Controller U1201 is a DP8473 disk controller which integrates all of the functions of the PC disk interface into a single IC All motor controls read and write signals and data are SR765 Dynamic Signal Analyzer Service Guide Circuit Description 2 9 controlled by the DP8473 A DMA channel is used to send and receive data from the controller in order to satisfy the disk drive timing GPIB Interface The GPIB IEEE 488 interface is provided by U1202 a TMS9914A controller U1203 and U1204 buffer data I O to the GPIB connector U1202 is programmed to provide an interrupt to the processor
73. amplitude 2 Press the keys in the following sequence Source lt On gt Input lt Input Config gt lt Channel gt Select Both Enter Chl Input Range 4 Enter Auto Scale A Auto Scale B Average it Avgs gt 2 5 Enter Display Average Select Vector Enter Marker Mode Link Select Harmonic Enter it Harmonics gt Link 5 Enter Link Marker Max 3 Record the THD reading for DisplayA from the THD menu box 4 Press Active Display Make DisplayB the active display 5 Record the THD reading for DisplayB from the THD menu box 6 This completes the harmonic distortion test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer 1 32 Performance Tests SR785 Performance Test Record Tested By Date Serial Number Firmware Revision Page 1 of 3 Equipment Used 1 Self Tests Test Power On Test Keypad Knob System RAM System ROM Video RAM Help ROM 2 DC Offset Input Range DispA Chl DispB Ch2 Upper Limit 30 dBV 50 dBV 3 Common Mode Rejection Input Range Frequency DispA Chl DispB Ch2 80 dBV 80 dBV Upper Limit 2 dBV 1 0 kHz 4 Amplitude Accuracy and Flatness Input Range Calibrator Ampl Lower Limit DispA Chl DispB Ch2 00 dB Upper Limit 46 dBV 2 509 mVrms 49 20 dBV 38 dBV 6 302 mVrms 41 20 dBV 30 dBV 15 830 mVrms 3
74. antalum 35V 20 Rad C 1454 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad J 1401 1 00236 109 120 PIN RT ANGL DIN Connector Male SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 7 Video IO Board Assembly Ref No SRS Part No Value Component Description N 1001 4 00334 425 10KX5 Resistor Network SIP 1 4W 2 Common N 1101 4 00284 421 1 0KX4 Res Network SIP 1 4W 2 Isolated N 1102 4 00863 421 1 2KX4 Res Network SIP 1 4W 2 Isolated N 1201 4 00221 425 150X5 Resistor Network SIP 1 4W 2 Common PCI 7 00523 701 MEGA VIDEO Printed Circuit Board Q 1001 3 0002 1 325 2N3904 Transistor TO 92 Package Q 1002 3 00022 325 2N3906 Transistor TO 92 Package Q 1101 3 00022 325 2N3906 Transistor TO 92 Package Q 1102 3 00022 325 2N3906 Transistor TO 92 Package Q 1103 3 00022 325 2N3906 Transistor TO 92 Package Q 1104 3 00022 325 2N3906 Transistor TO 92 Package Q 1105 3 00022 325 2N3906 Transistor TO 92 Package Q 1106 3 00022 325 2N3906 Transistor TO 92 Package R 1001 4 00088 401 51K Resistor Carbon Film 1 4W 596 R 1002 4 00034 401 10K Resistor Carbon Film 1 4W 596 R 1003 4 00021 401 1 0K Resistor Carbon Film 1 4W 596 R 1004 4 00785 402 100 Resistor Carbon Comp 1 2W 5 R 1101 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1102 4 00080 401 47 Resistor Carbon Film 1 4W 5 R 1103 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1104 4 00165 407 200 Resistor M
75. apacitor Electrolytic 35V 20 Rad C12 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 13 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C14 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C15 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 20 5 00124 526 5600U Capacitor Electrolytic 35V 20 Rad C21 5 00124 526 5600U Capacitor Electrolytic 35V 20 Rad C22 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 23 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C24 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C25 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 30 5 0004 1 509 220U Capacitor Electrolytic 50V 20 Rad C31 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 32 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 40 5 00041 509 220U Capacitor Electrolytic 50V 20 Rad C41 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C 42 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C50 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C51 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C52 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad C53 5 00127 524 2 2U Capacitor Tantalum 50V 20 Rad D1 3 00479 301 MUR410 Diode D2 3 00479 301 MUR410 Diode D3 3 00479 301 MUR410 Diode D4 3 00479 301 MUR410 Diode D5 3 00479 301 MUR410 Diode D6 3 00479 301 MUR410 Diode D7 3 00479 301 MUR410 Diode D8 3 00479 301 MUR410 Diode D9 3 00004 301 1N4148 Diode D 10 3 00004 301 1
76. apacitor Tantalum 35V 20 Rad C 355 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 356 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C357 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 360 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 361 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 362 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C371 5 00269 501 300P Capacitor Ceramic Disc 50V 10 SL C 372 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 373 5 00006 501 15P Capacitor Ceramic Disc 50V 10 SL C 378 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 379 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 388 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 389 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 390 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C391 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 394 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 395 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 23 Analog Input Board Assembly Ref No SRS Part No Value Component Description C 401 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C 402 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 403 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C 404 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U C
77. ards the front The knob is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis The knob is connected by a 5 wire ribbon cable to the keypad assembly Check that the cable is secure at both ends The keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT The cable attaches to the back of the keypad board on the front panel Make sure that the cable is firmly attached at both ends and that the cable is not damaged Check that the ground wire is attached firmly to the chassis and to the keypad board Push the Disk card inward to make sure that it is seated properly The knob signals are carried to the System backplane via this card If the knob still fails to function proceed to replace the digital pot SR785 Dynamic Signal Analyzer 3 16 Service 12 13 14 15 16 17 18 The digital pot is secured to the front panel bezel by a nut underneath the plastic knob on the outside Pry off the front cover of the plastic knob with a small screwdriver or your fingertips The cover is the plastic disk with the dimple in it Remove the plastic knob by loosening the nut which holds the plastic knob onto the digital pot s shaft Remove the mounting nut at the base of the shaft Once this nut is removed the pot can be removed from the bezel Pull the pot free while leaving the cable attached
78. arker is at 0 Hz The marker positions display above the graph should read 0 Hz The marker amplitude is the DC offset If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Output Offset pot to minimize the marker reading see Fig 8 3 9 Press Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 2 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 70 dBV remember 60 dBV is greater than 70 dBV and 80 dBV is less than 70 dBV then proceed to the next step If the reading is greater than 70 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 8 3 Service Guide SR785 Dynamic Signal Analyzer 3 26 Service 10 Press Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 5 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 85 dBV remember 80 dBV is greater than 85 dBV and 90 dBV is less than 85 dBV then proceed to the next step If the reading is greater than 85 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 8 3 11 Press Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 0 Enter
79. ast enough and U601B and U602A provide low frequency hysteresis R603 and N601A determine the level of hysteresis The DC trigger level is set by the 8 bit DAC U607A U606 buffers and shifts the DAC output The Trig_In signal is latched in PAL U703 which synchronizes the trigger to the A D clocks and interrupts the DSP Tachometer Service Guide The Tachometer input can be a TTL level signal or an analog signal T611 provides some common mode rejection for the trigger input Relay K615A selects TTL or Analog Level Tachometer Trigger TTL tachs proceed directly to the XOR gate U612B via some input protection At the heart of the analog tachometer input is the analog high speed comparator U605 LT1016 The input is buffered by U604A and limited by diodes D605 and D606 N602 divides the tach signal and tach level by two to accommodate the input range of the comparator C624 provides high frequency hysteresis when the output latch cannot respond fast enough and U604B and U612A provide low frequency hysteresis R623 and N602A determine the level of hysteresis The DC trigger level is set by the 8 bit DAC U607B U606D buffers and shifts the DAC output SR785 Dynamic Signal Analyzer 2 14 Circuit Description The Tach signals are latched in PAL U616 where slope selection and holdoff is implemented in conjunction with counter U613 PAL U714 receives the tach signal and interrupts the DSP Source Generator The source is output by DAC U501 AD
80. at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the DSP board in the Analyzer card cage nearest the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP board by using the card ejectors to release the board and pull the board up and out If replacing the DSP ROM remove U715 carefully with a chip puller Insert the new chip with the proper alignment the indentation faces up making sure not to bend or damage the pins Insert the new board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket Replace the card cage cover and tighten the cover screws 10 Replace the top lid and refasten the eight lid screws 11 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F2 Analog Board Replacement 1 Before replacing an Analog board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue SR785 Dynamic Signal Analyzer Service Guide 9 Service 3 19 Turn the power OFF Remove the power cord from the power entry module Remove the ei
81. board Use the DVM to measure the battery voltage at the BATT test point at the top of the board There are two test points BATT is the one towards the rear The battery voltage should be at least 2 7V relative to the chassis If the battery voltage is low then proceed to replace the battery Release the bar which secures the boards in place Remove the CPU board by using the card ejectors to release the board and pull the board up and out Desolder the two battery pins Cut the plastic tie which secures the battery and remove the battery Insert a new battery check the polarity solder the two pins Secure the battery with a new tie if available Replace the CPU board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Reset the unit by turning the power ON while holding down the backspace key If the unit continues to have battery problems then follow Procedure D1 to replace the CPU board Service Procedure D3 Video IO Board Replacement 1 2 3 4 Service Guide Before replacing the Video IO board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and
82. cked at 40 00 MHz by crystal oscillator U103 The external clock period is 2 oscillator cycles or 20 0 MHz The data and lower 16 bits of address are multiplexed on processor lines ADO AD15 U201 U202 U203 latch the address A0 A19 at the beginning of each memory or I O cycle U204 and U205 are bi directional data bus drivers which are active during the data read write portion of each memory or I O cycle U201 U205 provide the on board System bus Memory Map The 80C186 can address 1 Mbyte of memory and 64k of I O space The memory is mapped into 5 blocks Each block has 2 sockets one for the low byte and one for the high byte of data U301 U304 are 128 kbyte EPROMS mapped from 80000H to FFFFFH EPROMS U305 and U306 are mapped from 50000H to 7FFFFH for a total of 704 kbytes of program ROM U401 U404 are 128 kbyte CMOS static RAMs mapped from 00000H to 4FFFFH 320 kbytes U401 and U402 256 kbytes are battery backed up I O Map Service Guide U209 and U210 are the data bus drivers for the off board I O Expansion bus U206 and U207 are the data bus drivers for the off board External DSP bus U208 is the address driver for the External bus U213 is a PAL which enables the correct bus drivers depending upon the I O address space being accessed All memory accesses and on board I O use the System bus The 80C186 generates 7 peripheral chip select strobes each covering 128 byte I O addresses PCSO enables on board I O peripherals fron
83. ct the signal to the Trigger Input as well Verify that the signal appears in the top spectrum do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to External and verify that the Trig indicator in the display turns on If the unit does not trigger proceed to step 4 External TTL Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 kHz 0 5 Vrms sine wave to the Ch1 A input Use a BNC cable to connect the function generator TTL SYNC output to the Trigger Input as well Verify that the signal appears in the top spectrum do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to Ext TTL and verify that the Trig indicator in the display turns on If the unit does not trigger proceed to step 4 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards SR765 Dynamic Signal Analyzer Service Guide Service 3 21 See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the DSP board in the Analyzer card cage closest to the CRT Remove the card cage cov
84. d Circuit Thru hole Pkg U721 3 00055 340 7ALS74 Integrated Circuit Thru hole Pkg U 722 3 00055 340 7ALS74 Integrated Circuit Thru hole Pkg Service Guide SR785 Dynamic Signal Analyzer 4 20 Parts Lists DSP Board Assembly Ref No SRS Part No Value Component Description U 723 3 00274 340 T4AC74 Integrated Circuit Thru hole Pkg U 725 3 00195 340 CA3082 Integrated Circuit Thru hole Pkg U 801 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 802 3 00387 340 74HC245 Integrated Circuit Thru hole Pkg U 803 3 00387 340 74HC245 Integrated Circuit Thru hole Pkg U 804 3 00590 340 7T4ACTOO Integrated Circuit Thru hole Pkg U 805 3 00037 340 74HC138 Integrated Circuit Thru hole Pkg U 806 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 807 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 808 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 809 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 810 3 00604 342 2KX8 SERIAL EPROM PROM I C U 901 3 00114 329 7815 Voltage Reg TO 220 TAB Package U 902 3 00120 329 7915 Voltage Reg TO 220 TAB Package Z0 0 00012 007 TO 220 Heat Sinks Z0 0 00043 011 4 40 KEP Nut Kep Z0 0 00209 021 4 40X3 8PP Screw Panhead Phillips Z0 0 00231 043 4 SHOULDER Washer nylon Z0 0 00243 003 TO 220 Insulators Z0 0 00341 010 2 56 HEX Nut Hex Z0 0 00373 000 CARD EJECTOR Hardware Misc Z0 0 00728 021 2 56X1 2PP Screw Panhead Phil
85. d to Procedure F2 to replace the Analog board Otherwise contact SRS for more information Service Procedure F4 Checking the Amplitude 1 Check the amplitude accuracy by following the procedure outlined in Performance Test 4 Amplitude Accuracy and Flatness in Chapter 6 of the SR785 Operating Manual If the test passes then check the signal source in question If the test fails follow Procedure F2 to replace an Analog board Service Procedure F5 Checking the Trigger 1 4 Internal Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 kHz 0 5 Vrms sine wave to both A inputs Verify that the signal appears in both spectra do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to Chl and verify that the Trig indicator in the display turns on Set the Trigger Source to Ch2 and verify that the Trig indicator turns on If neither trigger source works follow Procedure F1 to replace the DSP board If one of the internal sources fails the problem is probably with the Analog board for that channel Follow Procedure F2 to replace the Analog board If both trigger sources are OK continue External Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 KHz 0 5 Vrms sine wave to the Ch1 A input Use a BNC cable to conne
86. d up and out There are three memory SIMM modules on the DSP board They are the DRAM Data Memory and Program Memory The Data and Program modules are SRS custom parts and must be replaced with SRS supplied parts The standard DRAM buffer is a 2Mx32 70ns or faster 72 pin SIMM The DRAM upgrades are 4Mx32 and 8Mx32 70ns or faster 72 pin SIMM s The DRAM module must have its identification pin s grounded in order to work in the SR785 These pins are standard in all modules but may not be connected in modules not supplied by SRS Check the data sheet for the module to ensure that the correct ID pins are connected To remove a memory module simply release the spring latches at each end of the socket Insert the new module making sure that the notch end is correctly positioned Make sure that the spring latches are engaged around the edge of the board Replace the DSP board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket Replace the card cage cover and tighten the cover screws 12 13 Replace the top lid and refasten the eight lid screws Reset the unit by turning the power ON while holding down the backspace
87. e board up and out Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Replace the two screws which secure the power supply shield to the rear panel Replace the bar which secures the boards in place Replace the top lid and refasten the eight lid screws Service Procedure A2 Power Supply Check P Service Guide 1 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Check the AC power source for the correct line voltage either 100V 120V 220V or 240V AC rms Make sure that the power cord is OK Verify that the Line Voltage Selector card located in the rear panel fuse holder is set so that the correct AC input voltage value is visible Conversion to other AC input voltages requires a change in the fuse holder voltage card position and fuse value Disconnect the power cord open the fuse holder cover door and rotate the fuse pull lever to remove the fuse Remove the small printed circuit board and select the operating voltage by orienting the printed circuit board so that the desired voltage is visible when pushed firmly into its slot Rotate the fuse pull lever back into its normal p
88. e state machine and generates an interrupt I O Interface Trigger The A D converters on the analog boards send a serial data stream to the DSP board Each analog board uses a dual 16 bit converter with both channels digitizing the signal Each board returns two data streams for a total of four A D channels U401 U404 and U405 U408 are 32 bit serial to parallel converters each receiving two 16 bit data channels from a single analog board U409 U410 is a 16 bit parallel to serial converter which sends DSP data to the source D A converter The Trigger input can be a TTL level signal or an analog signal T601 provides some common mode rejection for the trigger input Relay K602 selects TTL or Analog Level Trigger Relay K601 allows the trigger signal to come from the output of the analog front end amplifiers or the external TRIGGER front panel BNC Trigger signals pass through the XOR gate U602C where rising or falling edge trigger slope is selected TTL triggers proceed directly to the XOR gate via some input protection Analog level signals are first converted to a TTL signal via high speed comparator U603 At the heart of the trigger input is the analog high speed comparator U603 LT1016 The input is buffered by U601A and limited by diodes D601 and D6302 N601 divides the trigger signal and trigger level by two to accommodate the input range of the comparator C604 provides high frequency hysteresis when the output latch cannot respond f
89. ed to the outlet ground to protect against electrical shock Always use an outlet which has a properly connected protective ground Service Do not attempt to service or adjust this instrument unless another person capable of Y providing first aid or resuscitation is present Do not install substitute parts or perform any unauthorized modifications to this STOP instrument Contact the factory for instructions on how to return the instrument for authorized service and adjustment Fan The fans in the SR785 are required to maintain proper operation Do not block the vents in the chassis or the unit may not operate properly Service Guide SR785 Dynamic Signal Analyzer SR785 Dynamic Signal Analyzer Service Guide Contents Safety and Preparation For Use Contents Table of Figures Chapter 1 Performance Tests Getting Ready Self Tests DC Offset Common Mode Rejection Amplitude Accuracy Amplitude Linearity Anti alias Filter Attenuation Frequency Accuracy Phase Accuracy Noise and Spurious Signals Sine Source Harmonic Distortion Performance Test Record Chapter 2 Circuit Description Overview CPU Board Video IO Board Power Supply Board DSP Board Analog Input Boards Chapter 3 Service Service Guide Before Proceeding With Service Troubleshooting Table Circuit Board Locations Service Procedures Caution Required Equipment Power Supply Board Replacement Power Supply Check CRT Replacement CRT Check Keypad Check
90. egrated Circuit Thru hole Pkg U 202 3 00585 340 7AACT573 Integrated Circuit Thru hole Pkg U 203 3 00585 340 7AACTS573 Integrated Circuit Thru hole Pkg U 204 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U 205 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U 206 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U 207 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U 208 3 00585 340 7AACTS573 Integrated Circuit Thru hole Pkg U 209 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U 210 3 00586 340 T4ACT245 Integrated Circuit Thru hole Pkg U211 3 00587 340 T4ACT32 Integrated Circuit Thru hole Pkg U 212 3 00588 340 T4ACT08 Integrated Circuit Thru hole Pkg U 213 3 00693 343 SR780 U213 GAL PAL I C U 214 3 00692 343 SR780 U214 GAL PAL I C U 216 3 00587 340 T4ACT32 Integrated Circuit Thru hole Pkg U 401 3 0055 1 341 128KX8 70 STATIC RAM I C U 402 3 0055 1 341 128K X8 70 STATIC RAM I C U 403 3 0055 1 341 128KX8 70 STATIC RAM I C U 404 3 0055 1 341 128K X8 70 STATIC RAM I C U501 3 00342 340 T4ALS 138 Integrated Circuit Thru hole Pkg U 503 3 00342 340 T4ALS 138 Integrated Circuit Thru hole Pkg U 504 3 00274 340 T4AC74 Integrated Circuit Thru hole Pkg U 505 3 00347 340 TALS 148 Integrated Circuit Thru hole Pkg U 506 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg U 507 3 00043 340 74HC21 Integrated Circuit Thru hole Pkg U 508 3 00303 340 74HC164 Integrated Circuit Thru hole
91. ems or its authorized representatives Potentially lethal voltages are present in this instrument This unit is to be serviced by qualified service personnel only There are no user serviceable parts inside Check the red LED at the top edge of Power Supply board The unit is safe only if the LED is OFF If the LED is ON then voltages are present within the unit USE CAUTION Use caution when checking circuits with the power on Always disconnect the power cord before replacing or servicing any component inside the chassis Reset the unit by turning the power off and back on while holding down the backspace key This clears the stored setup and re initializes the instrument If the problem is solved do not proceed to service any internal components If the problem continues proceed with the proper service procedures Always reset the instrument after performing any service The only field service which may be performed is at the board and assembly level If the DSP board or either Analog Input board is replaced with factory calibrated replacement boards the unit will remain calibrated If individual components are replaced on a board the calibration is not guaranteed Individual component replacement on the DSP or Analog boards is not recommended SR785 Dynamic Signal Analyzer 3 4 Service Troubleshooting Table Symptoms Procedure Screen is blank when Does the unit beep when front panel keys are pressed p
92. er by loosening the five screws in the cover Remove the DSP board by using the card ejectors to release the board and pull the board up and out Use the DVM to verify that the Trigger Input BNC center conductor and shield are connected to the rear most SMB jack at the bottom of the card cage directly behind the Trigger Input The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield If the connection is OK follow Procedure F1 to replace the DSP board Otherwise contact SRS for more information Service Procedure F6 Checking the Source 1 Check the source output on the oscilloscope Reset the unit by holding down the backspace key while turning the power ON Connect the Source Output to the oscilloscope In the Source menu choose Sine A 10 24 kHz 1 0 Vpp sine wave should be displayed on the oscilloscope If not continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the DSP board in the Analyzer card cage closest to the CRT Remove the card cage cover by loosening the five screws in the cover
93. etal Film 1 8W 1 50PPM R 1105 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1106 4 00141 407 100 Resistor Metal Film 1 8W 1 50PPM R 1107 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 1108 4 00027 401 1 5K Resistor Carbon Film 1 4W 5 R 1109 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1110 4 00080 401 47 Resistor Carbon Film 1 4W 5 R1111 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1112 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1113 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1114 4 00141 407 100 Resistor Metal Film 1 8W 1 50PPM R 1115 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 1116 4 00027 401 1 5K Resistor Carbon Film 1 4W 5 R1117 4 00041 401 150 Resistor Carbon Film 1 4W 5 R 1201 4 00273 401 5 6K Resistor Carbon Film 1 4W 5 R 1202 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 1204 4 00090 401 560 Resistor Carbon Film 1 4W 5 R 1205 4 00090 401 560 Resistor Carbon Film 1 4W 5 R 1301 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 1302 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 1303 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 1304 4 00084 401 5 1K Resistor Carbon Film 1 4W 5 SO1201 1 00232 150 52 PLCC TH Socket THRU HOLE TP2 1 00143 101 TEST JACK Vertical Test Jack TP101 1 00143 101 TEST JACK Vertical Test Jack TP102 1 00143 101 TEST JACK Vertical Test Jack TP103 1 00143 101 TEST JACK Vertical
94. etes the frequency accuracy test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer 1 22 Performance Tests SR785 Dynamic Signal Analyzer Performance Tests 1 23 8 Phase Accuracy This test measures the phase accuracy of the analyzer This test measures the phase of a signal relative to the trigger Setup We will use the frequency synthesizer to provide the signal Connect the output of the frequency synthesizer to the Trigger Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 10 240 kHz and an amplitude of 500 mVrms 3 Press the keys in the following sequence Input lt Input Config gt lt Channel gt Select Both Enter Chl Input Range 2 lt dBV gt Chl Coupling Select AC Enter Trigger Trigger Source Select Ch1 Enter Auto Scale A Auto Scale B Marker Marker Select Link Enter Marker Max Display Setup View Select Phase Enter Active Display Make DisplayB the active display SR765 Dynamic Signal Analyzer 1 24 Performance Tests Display Setup lt View gt Select Phase Enter Auto Scale A Auto Scale B Average lt Avgs gt 1 0 Enter Display Avg Select Vector
95. f No SRS Part No Value Component Description U 604 3 00064 340 CA3081 Integrated Circuit Thru hole Pkg U 605 3 00049 340 7A4HC74 Integrated Circuit Thru hole Pkg U 606 3 00604 342 2KX8 SERIAL EPROM PROM I C U 607 3 00694 343 SR780 U607 GAL PAL I C U 608 3 00155 340 74HC04 Integrated Circuit Thru hole Pkg U 609 3 00037 340 74HC138 Integrated Circuit Thru hole Pkg U610 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 630 3 00343 340 T4ALS32 Integrated Circuit Thru hole Pkg U 690 3 00116 325 78L05 Transistor TO 92 Package Z0 0 00012 007 TO 220 Heat Sinks Z0 0 00043 011 4 40 KEP Nut Kep Z0 0 00209 021 4 40X3 8PP Screw Panhead Phillips Z0 0 00231 043 4 SHOULDER Washer nylon Z0 0 00243 003 TO 220 Insulators Z0 0 00373 000 CARD EJECTOR Hardware Misc Z0 0 00516 042 BNC Washer lock SR765 Dynamic Signal Analyzer Service Guide Analyzer Backplane Parts List Parts Lists 4 31 This section covers schematics M780 1 through M780 4 in Chapter 5 Analyzer Backplane Assembly Ref No SRS Part No Value Component Description CI 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C2 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C3 5 00023 529 IU Cap Monolythic Ceramic 50V 20 Z5U C 4C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C5C 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U C6 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C7C 5 002
96. faces and the disk controller Video Graphics Interface The video graphics interface is centered around U1003 an HD63484 graphics controller The HD63484 generates the video sync signals controls the video memory draws graphic primitives such as lines circles polygons etc and performs many memory to memory functions The HD63484 relieves the 80C186 from having to calculate each video image and greatly increases display speed Commands and data are sent from the 80C186 to the HD63484 using a DMA channel This allows the HD63484 to process commands without having to wait for the 80C186 to send them U1006 and U1007 are 128 kbyte RAMs which make up the 256k video memory Each pixel is made up of 2 bits The video screen is 800H by 600V and requires 120 000 bytes of memory The remaining memory is used to store patterns and fonts as well as a second display screen The data and address are multiplexed and U1004 and U1005 are the address latches Memory is accessed twice during each display cycle The first access reads the 16 bits of video data for the current display cycle The second access is used by the controller for drawing purposes During the drawing access data at any address may be read or written This allows drawing to take place as fast as possible Data is read 16 bits at a time When data is required for the display the even data bits are latched into U1008 and the odd data bits are latched into U1009 U1008 and U1009 are par
97. g U 362 3 0009 1 340 LF412 Integrated Circuit Thru hole Pkg U 370 3 00089 340 LF357 Integrated Circuit Thru hole Pkg U 371 3 00089 340 LF357 Integrated Circuit Thru hole Pkg U 374 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 376 3 00385 340 74HC4053 Integrated Circuit Thru hole Pkg U 391 3 00143 340 LM393 Integrated Circuit Thru hole Pkg U 392 3 00143 340 LM393 Integrated Circuit Thru hole Pkg U 401 3 00392 340 PCM1750P Integrated Circuit Thru hole Pkg U 402 3 00155 340 74HC04 Integrated Circuit Thru hole Pkg U 403 3 0009 1 340 LF412 Integrated Circuit Thru hole Pkg U501 3 00118 325 78L15 Transistor TO 92 Package U 502 3 00124 325 79L15 Transistor TO 92 Package USII 3 00096 340 LM317L Integrated Circuit Thru hole Pkg U521 3 00116 325 78L05 Transistor TO 92 Package U 522 3 00122 325 79L05 Transistor TO 92 Package U531 3 00114 329 7815 Voltage Reg TO 220 TAB Package U 532 3 00120 329 7915 Voltage Reg TO 220 TAB Package U 541 3 00096 340 LM317L Integrated Circuit Thru hole Pkg U 542 3 00100 340 LM337L Integrated Circuit Thru hole Pkg U551 3 00346 329 7812 Voltage Reg TO 220 TAB Package U 601 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 602 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg U 603 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg Service Guide SR785 Dynamic Signal Analyzer 4 30 Parts Lists Analog Input Board Assembly Re
98. ght black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 2 to locate the Analog boards in the Analyzer card cage behind the input BNC connectors Remove the card cage cover by loosening the five screws in the cover The Channel 1 Analog board is in the center of the card cage The Channel 2 Analog board is on the right Pull off the small shield at the front using the finger hole Remove the correct Analog board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket Replace the small shield at the front Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws 10 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F3 Checking the Analog Inputs Service Guide 1
99. grated Circuit Thru hole Pkg U 108 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 109 3 00461 340 OPA2604 Integrated Circuit Thru hole Pkg U 201 3 00385 340 74HC4053 Integrated Circuit Thru hole Pkg U 202 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 203 3 00385 340 74HC4053 Integrated Circuit Thru hole Pkg U 204 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 206 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 207 3 00371 340 DG444 Integrated Circuit Thru hole Pkg U 208 3 00371 340 DG444 Integrated Circuit Thru hole Pkg U 220 3 00143 340 LM393 Integrated Circuit Thru hole Pkg U 230 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 231 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 232 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 233 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 234 3 00768 340 5534 TI ONLY Integrated Circuit Thru hole Pkg U 240 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 241 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 242 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 243 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 244 3 00130 340 5532A Integrated Circuit Thru hole Pkg U 310 3 00130 340 5532A Integrated Circuit Thru hole Pkg U317 3 00886 340 OPA2134 Integrated Circuit Thru hole Pkg U 360 3 00116 325 78L05 Transistor TO 92 Package U 361 3 00059 340 AD7542JN Integrated Circuit Thru hole Pk
100. hold the power supply shield to the chassis These screws prevent accidental removal of this board The unit should never be operated without these screws in place Power Supply Connector The 120 pin connector carries all of the necessary interconnections to the System backplane Switch AC and the transformer secondaries are carried by this connector The supply outputs to the System and Analyzer backplanes is also carried by this connector For safety this board cannot be inserted backwards Test Points The test points along the top edge of the board are provided for supply testing while the instrument is powered ON These test points are current limited for safety Always measure the supply voltages relative to the correct ground test point as labeled on the board System Power The system power for the System backplane CPU Video IO disk drive and CRT is provided by the switching power supply module mounted on the Power Supply board This switcher is inside the power supply shield The switcher accepts AC line input and generates 5V 5V 12V and 12V The 5V powers all of the system logic CPU and Video IO as well as the DSP logic 12V powers the CRT and the fans Analog Power Analog power to the Analyzer backplane is generated by a linear power supply The transformer on the rear panel provides two 41VAC center tapped secondaries and two 26V AC secondaries The 41V AC secondaries are used to generate 20VDC supplies for the a
101. hting Filter The A Weighting filter is constructed with a standard implementation using U310A and U310B Relay K301 selects the filter U317 is a dual amplifier which splits the signal into two paths inverted and non inverted Each signal path drives one of the A D channels Comparator U391 detects overload based upon the A D converter reference voltage A D Converter The A D Converter converts the inverted and non inverted signals to two digital data streams Conversion takes place at a rate of 262 144 samples per second FFT Basez102 4 kHz A Burr Brown PCM1750 dual 18 bit A D converter is used for this purpose U402A and U402D drive the data signals to the Analyzer backplane and to the DSP board Timing signals for the A D Converter are received via U402B and U402C I O Interface The Analog Input board is configured by the DSP board via its serial I O Interface U601 U603 form a 24 bit shift register and latch Data is shifted in serially from the DSP board and latched to internal latches The outputs of the latches are used to control relays switches etc During normal operation this interface is static and no random digital noise is present on this board SR765 Dynamic Signal Analyzer Service Guide Power Service Guide Circuit Description 2 17 U606 is a serial EEPROM containing the calibrations for the amplifier and anti aliasing filter U606 is read by the host CPU 80C186 via a port on the DSP board This EEPROM is only
102. ice Guide Chapter 1 Performance Tests 1 1 The performance tests described in this section are designed to verify with a high degree of confidence that the unit is performing within the specifications The results of each test should be recorded on the test sheet at the end of this section In This Chapter Getting Ready Hardkeys Softkeys Knob Reset Serial Number Firmware Revision Necessary Equipment Warm Up The Test Record If A Test Fails Self Tests DC Offset Common Mode Rejection Amplitude Accuracy and Flatness Amplitude Linearity Anti alias Filter Attenuation Frequency Accuracy Phase Accuracy o co 0 0 F ORN Noise and Spurious Signals 10 Sine Source 11 Harmonic Distortion SR785 Performance Test Record SR765 Dynamic Signal Analyzer 1 2 Performance Tests SR785 Dynamic Signal Analyzer Performance Tests 1 3 Getting Ready Hardkeys The keypad consists of four groups of hardkeys keys with printed labels Hardkeys are referenced in braces like Active Display or Input The ENTRY keys are used to enter numeric parameters which have been highlighted by a soft key The MENU keys select a menu of soft keys Pressing a menu key will change the menu boxes which are displayed next to the soft keys Each menu presents a group of similar or related parameters and functions The CONTROL keys start and stop data acquisition toggle the active display and link pa
103. in the SR785 Each circuit board s function and operation is discussed The schematics for each board are shown in Chapter 5 In This Chapter Overview System Components Analyzer Components Schematic Diagram Locations CPU Board Microprocessor System Memory Map I O Map String ROM Keypad Interface Spin Knob Keyboard Interface Speaker Clock Calendar Reset Battery Switch Printer Interface Expansion Connector Video IO Board Video Graphics Interface Disk Controller GPIB Interface RS232 Interface Expansion Connector Power Supply Board Caution Removing the Power Supply Power Supply Connector Test Points System Power Analog Power DSP Board Digital Signal Processor Timing Signal Generator Service Guide 2 3 23 2 4 2 5 2 5 2 5 2 6 2 6 2 6 2 6 2 6 2 7 2 7 2 7 2 8 2 8 2 9 2 9 2 9 2 10 2 10 2 10 2 10 2 10 2 10 2 10 2 12 2 12 2 12 I O Interface Trigger Tachometer Source Generator Interface To CPU Analog Input Boards Input Amplifier Gain Stages And Attenuators Anti Aliasing Filter A Weighting Filter A D Converter I O Interface Power 2 13 2 13 2 13 2 14 2 14 2 15 2 15 2 15 2 16 2 16 2 16 2 16 2 17 SR785 Dynamic Signal Analyzer 2 2 Circuit Description SR765 Dynamic Signal Analyzer Service Guide 2 3 Overview The SR785 s circuitry is divided into two major sections the system section and the analyzer section The system section contains the m
104. inute this will not affect the test results Auto Offset must be left enabled On in the Input lt More gt menu Disabling Auto Offset may invalidate the results of some tests The Test Record Make a copy of the SR785 Performance Test Record at the end of this section Fill in the results of the tests on this record This record will allow you to determine whether the tests pass or fail and also preserve a record of the tests If A Test Fails If a test fails you should check the settings and connections of any external equipment and if possible verify its operation using a DVM scope or some other piece of test equipment After checking the setup repeat the test from the beginning to make sure that the test was performed correctly SR785 Dynamic Signal Analyzer Performance Tests 1 5 If the test continues to fail contact Stanford Research Systems for further instructions Make sure that you have the unit serial number and firmware revision code handy Have the test record on hand as well SR765 Dynamic Signal Analyzer 1 6 Performance Tests SR785 Dynamic Signal Analyzer Performance Tests 1 7 1 Self Tests The self tests check the analyzer hardware These are functional tests and do not relate to the specifications These tests should be run before any of the performance tests Note that the Test menu offers more tests than are required here Only those tests which require no additional equipment are discussed in
105. it s next to the Power Supply board Remove the CPU board by using the card ejectors to release the board and pull the board up and out If replacing the program ROM s remove U301 306 carefully using a chip puller Install the new ROMs making sure to place each ROM chip in the correct socket to properly align the chip the indentation on the chip faces the center of the board and to avoid damaging or bending the pins If replacing the the two help ROMs repeat this procedure for U801 and U802 Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket SR785 Dynamic Signal Analyzer Service Guide 9 Service 3 17 Replace the bar which secures the boards in place 10 Replace the top lid and refasten the eight lid screws 11 Reset the unit by turning the power ON while holding down the backspace key Service Procedure D2 Battery Check Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 8 1 to locate the CPU board it s next to the Power Supply
106. k between the user s input signal and the DSP processor From the front panel BNC the user s signal passes through a low distortion front end amplifier gain stages attenuators anti aliasing filter and finally an A D Converter Once converted to digital form the input signal is ready to be processed by the DSP The two inputs use identical Analog Input boards The routing on the Analyzer backplane keeps them separate Input Amplifier The goal of any measurement instrument is to perform some given measurement while affecting the quantities to be measured as little as possible As such the input amplifier is often the most critical stage in the entire signal path The design of the front end input amplifier in the SR785 was driven by an effort to provide optimum performance in the following areas input voltage noise input current noise input capacitance harmonic distortion and common mode rejection CMR To provide such performance an FET differential input amplifier with common mode feedback architecture was chosen The input signal is first passed through a series of relays to select input mode K102 input coupling K104 and input attenuation K105 K108 Relay K101 provides shield grounding Relay K106 switches in the ICP current supply The 30 dB input attenuator formed by resistors R103 R106 serves to attenuate very large signals as well as providing protection to the input FET in the presence of very high voltages gt 50 Vpk
107. kage R 201 4 00065 401 3 3K Resistor Carbon Film 1 4W 5 R 202 4 00065 401 3 3K Resistor Carbon Film 1 4W 5 R 502 4 00065 401 3 3K Resistor Carbon Film 1 4W 5 R 707 4 00065 401 3 3K Resistor Carbon Film 1 4W 5 R710 4 00080 401 47 Resistor Carbon Film 1 4W 5 R711 4 00080 401 47 Resistor Carbon Film 1 4W 5 R712 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R713 4 00080 401 47 Resistor Carbon Film 1 4W 5 R714 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R716 4 00054 401 200K Resistor Carbon Film 1 4W 5 SO101 1 00108 150 PLCC 68 TH Socket THRU HOLE S0301 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0302 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0303 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0304 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0305 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0306 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0801 1 00156 150 32 PIN 600 MIL Socket THRU HOLE S0802 1 00156 150 32 PIN 600 MIL Socket THRU HOLE SR785 Dynamic Signal Analyzer Service Guide Parts Lists 4 5 CPU Board Assembly Ref No SRS Part No Value Component Description TP701 1 00143 101 TEST JACK Vertical Test Jack TP702 1 00143 101 TEST JACK Vertical Test Jack U 101 3 00595 360 80C186 20 Integrated Circuit Surface Mount Pkg U 102 3 00591 340 T4ACT04 Integrated Circuit Thru hole Pkg U 103 6 00147 621 40 000 MHZ Crystal Oscillator U 201 3 00585 340 T4ACT5S73 Int
108. ling Select AC Enter Average Averaging Type Select Linear Fix Len Enter d Avgs gt 1 0 Enter Display Avg Select RMS Enter SR765 Dynamic Signal Analyzer 1 14 Performance Tests 3 Amplitude accuracy is verified at 1 0 kHz and various input ranges For each range setting in the table below perform steps 3a through 3d Input Range pk AC Calibrator Amplitude 46 dBV 2 509 mVrms 38 dBV 6 302 mVrms 30 dBV 15 830 mVrms 14 dBV 99 881 mVrms 4 dBV 0 7934 Vrms 10 dBV 1 5830 Vrms 22 dBV 6 3021 Vrms 34 dBV 25 089 Vrms a Set the AC calibrator to the amplitude shown in the table b Press Input Chl Input Range Enter the range from the table c Press Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max d Record the marker Y reading for both displays for each range 4 Frequency response is checked at frequencies above 1 kHz The test frequencies are listed below The measurements are performed for two different input ranges Test Frequencies 24 kHz 48 kHz 72 kHz 96 kHz a Set the AC calibrator to 1 0 kHz and an amplitude of 99 881 mVrms b Set the frequency synthesizer to 1 0 kHz c Press Frequency lt Center Frequency gt 1 Select kHz Enter SR785 Dynamic Signal Analyzer Performance Tests 1 15 Input Chl Input Range 1 4 Enter Start Reset Wait for the average to finish Auto Scale
109. lips SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 21 Analog Input Board Parts List This section covers schematics A780 1 through A780 7 in Chapter 5 The SR785 uses two of these boards Analog Input Board Assembly Ref No SRS Part No Value Component Description C101 5 00060 512 1 0U Cap Stacked Metal Film 50V 5 40 85c C 102 5 00060 5 12 1 0U Cap Stacked Metal Film 50V 5 40 85c C 104 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 105 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 106 5 00159 501 6 8P Capacitor Ceramic Disc 50V 10 SL C110 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 156 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 157 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 158 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 159 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 160 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 161 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 162 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 163 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 165 5 00227 526 100U Capacitor Electrolytic 35V 20 Rad C 166 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 167 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 180 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 181 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U
110. m 1 8W 1 50PPM R 128 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM R 129 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM R 141 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 142 4 00411 407 1 37K Resistor Metal Film 1 8W 1 50PPM R 143 4 00411 407 1 37K Resistor Metal Film 1 8W 1 50PPM R 144 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 146 4 00696 407 43 2K Resistor Metal Film 1 8W 1 50PPM R 152 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 153 4 0003 1 401 100 Resistor Carbon Film 1 4W 5 R 154 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 155 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 156 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 157 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 160 4 00329 407 402 Resistor Metal Film 1 8W 1 50PPM R 161 4 00086 401 51 Resistor Carbon Film 1 4W 5 R 162 4 00192 407 49 9K Resistor Metal Film 1 8W 1 50PPM R 163 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 164 4 00440 407 121K Resistor Metal Film 1 8W 1 50PPM R 165 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 166 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 201 4 00380 407 6 34K Resistor Metal Film 1 8W 1 50PPM R 202 4 00556 407 2 94K Resistor Metal Film 1 8W 1 50PPM R 203 4 00164 407 20 0K Resistor Metal Film 1 8W 1 50PPM R 204 4 00556 407 2 94K Resistor Metal Film 1 8W 1 50PPM R 205 4 00764 407 9 31K Resistor Metal
111. mic 50V 80 20 Z5U AX C 908 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 909 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C910 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C911 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 912 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C913 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C914 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C915 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C916 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 917 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C918 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C919 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 920 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C921 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 922 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 923 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 924 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 925 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 926 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 927 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 928 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 929 5 00262
112. nalog inputs and the source output The 26VAC secondaries generate 30V isolated supplies for the ICP power SR785 Dynamic Signal Analyzer Service Guide Service Guide Circuit Description 2 11 Bridge rectifiers D1 D4 and D5 D8 rectify the 41V AC secondaries Filter capacitors C10 C11 and C20 C21 provide filtered 28 VDC Resistors provide a bleed current on all of the unregulated supply filter capacitors Because of the large capacitance in this circuit the time for the voltages to bleed to zero is about a minute after the power is turned off The 20VDC supplies are generated by voltage regulators U10 U11 and U20 U21 These supplies are floating on this board The ground reference for 20V_D source power is on the DSP board This supply floats if no DSP board is plugged in The ground reference for 20V_A analog power is on the analog input boards This supply floats if no analog input board is plugged in The 30V supplies are very low current and only require small 100 mA regulators U30 and U40 SR785 Dynamic Signal Analyzer 2 12 Circuit Description DSP Board This section covers schematics D785 1 through D785 11 in Chapter 5 The DSP board takes digital inputs from the A D Converters on the Analog Input boards and performs all of the computations related to the measurement before it is displayed on the screen This includes digital heterodyning frequency shifting digital filtering and downsampling Fast Fourier Transformi
113. nals are carried to the System backplane via this card Replace the front panel bezel being careful to engage the slots which secure the front of the Disk card Replace the eight bezel screws Replace the handle and the pivot screws 12 If the keypad still does not function then the problem may be on the CPU board The keypad circuit board contains no active circuitry and the rubber keys are very unlikely to fail To replace the CPU board follow Procedure D1 CPU Board Replacement Replace the top lid and refasten the eight lid screws Service Procedure C2 Knob Check Service Guide 1 10 11 Perform the Knob check in the System lt Diagnostics gt menu Verify knob rotation and direction If the test passes then the knob is OK If the test fails or cannot be completed then proceed Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom Remove the front panel bezel by pulling it slowly off tow
114. nalyzer Components The analyzer section is in the right half of the chassis directly behind the keypad A card cage contains the DSP board and two identical analog input boards The analyzer boards are interconnected by a backplane board under the card cage This backplane extends all the way to the front panel BNC connectors The analyzer backplane connects to the system backplane via two short cables at the center of the chassis just behind the CRT Service 3 9 Figure 8 2 Analyzer Components Chassis Top View DSP Board Chl Analog Input Board Ch2 Analog Input Board Analyzer Backplane Front Schematic Diagram Locations Schematic diagrams are located in Chapter 10 Service Guide Board Assembly Schematic s see Chapter 10 CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Board MKEY 1 DSP Board D785 1 through D785 11 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 SR785 Dynamic Signal Analyzer 3 10 Service Service Procedures Caution Potentially lethal voltages are present in this instrument This unit is to be Va serviced by qualified service personnel only There are no user serviceable parts inside Check the red LED at the top edge of Power Supply board The unit is safe only if the LED is OFF If the LED is ON then voltages are
115. nector J31C 1 00224 141 STRAIGHT PLUG SMB Connector J 33C 1 00224 141 STRAIGHT PLUG SMB Connector J 34C 1 00224 141 STRAIGHT PLUG SMB Connector J35C 1 00224 141 STRAIGHT PLUG SMB Connector J 36C 1 00224 141 STRAIGHT PLUG SMB Connector J 40C 1 00235 108 96 PIN VERTICAL DIN Connector Female JP5B 1 00242 130 20 PIN ELH VERT Connector Male JP11C 1 00272 130 34 PIN DI Connector Male JP13C 1 00272 130 34 PIN DI Connector Male JP50C 1 00251 130 10 PIN DIL Connector Male PCIA 7 00524 701 SR780 MOTHER Printed Circuit Board PCIB 7 00626 701 MEGAPLAT D D Printed Circuit Board PCIC 7 00797 701 SR785 BACKPLANE Printed Circuit Board RIA 4 00772 402 33 Resistor Carbon Comp 1 2W 5 RIB 4 00098 401 680 Resistor Carbon Film 1 4W 5 Z0 0 0001 1 057 GROMMET Grommet Z0 0 00014 002 6J4 Power_Entry Hardware Z0 0 00043 011 4 40 KEP Nut Kep Service Guide SR785 Dynamic Signal Analyzer 4 32 Parts Lists Analyzer Backplane Assembly Ref No SRS Part No Value Component Description Z0 0 00079 031 4 40X3 16 M F Standoff Z0 0 00081 032 320882 Termination Z0 0 00089 033 4 Tie Z0 0 00098 042 6 LOCK Washer lock Z0 0 00114 050 10 1 8 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00135 050 7 5 8 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00149 020 4 40X1 4PF Screw Flathead Phillips Z0 0 00150 026 4 40X1 4PF Screw Black All Types Z0 0 00157 000 BNC PLUG Hardware Misc Z0 0 00167 023 6 32X
116. nector Amp MTA 156 Z0 1 00273 171 10 COND DIL Cable Assembly Ribbon Z0 1 00274 171 20CONDX8 Cable Assembly Ribbon Z0 2 00034 220 ENAIJ B20 SOFTPOT Z0 2 00040 211 DPDT Switch Rocker Z0 3 00600 341 128KX8 20 STATIC RAM LC Z0 4 00541 435 130V 1200A Varistor Zinc Oxide Nonlinear Resistor Z0 5 00298 568 01U Cap Ceramic 50V SMT 1206 10 X7R Z0 5 00334 569 IU T35 Cap Tantalum SMT all case sizes Z0 6 00043 611 1 5A 3AG Fuse Z0 6 00176 610 SR780 Transformer Z0 6 00212 630 1 X 25 CYL Ferrite Beads Z0 7 00124 720 TRANSCOVER2 MOD Fabricated Part Z0 7 00539 720 SR780 5 Fabricated Part Z0 7 00540 720 SR780 6 Fabricated Part Z0 7 00544 720 SR780 10 Fabricated Part Z0 7 00545 720 SR780 12 Fabricated Part Z0 7 00546 720 SR780 13 Fabricated Part Z0 7 00547 720 SR780 14 Fabricated Part Z0 7 00549 720 SR780 16 Fabricated Part Z0 7 00550 720 SR780 17 Fabricated Part Z0 7 00551 721 SR780 18 Machined Part Z0 7 00552 721 SR780 19 Machined Part Z0 7 00553 720 SR780 20 Fabricated Part Z0 7 00554 720 SR780 21 Fabricated Part Z0 7 00555 720 SR780 23 Fabricated Part Z0 7 00621 720 SR780 28 Fabricated Part Z0 7 00623 720 SR780 30 Fabricated Part Z0 7 00624 720 SR780 31 32 Fabricated Part Z0 7 00625 720 SR780 7 Fabricated Part Z0 7 00627 740 SR780 33 34 Keypad Conductive Rubber Z0 7 00628 701 MEGA KEYPAD Printed Circuit Board Z0 7 00630 701 SIMM Printed Circuit Board Z0 7 00632 735 SR780 35 Injection Molded Plastic Z0 7 006
117. ng averaging and output display processing scaling magnitude calc log sqrt etc These functions are implemented within a system comprised of four functional blocks the Digital Signal Processor DSP the Timing Generator the I O Interface and the Trigger Input The fifth functional block is the Source Generator The source is synthesized filtered and attenuated before being passed to the output connector Digital Signal Processor The SR785 utilizes a single ADSP21020 digital signal processor clocked at 33 MHz All instructions are completed in a single 30 ns cycle The ADSP21020 has two external data buses Data Memory DM and Program Memory PM There is no internal memory Program memory is 256k x 48 and Data memory is 256k x 40 The memory is mounted on four SIMM modules Each SIMM module contains 128k words of 20 ns 128k x 8 memory IC s In addition a 2M x 32 DRAM module is located on the DM bus This module may be upgraded to or 8M x 32 PAL U301 provides simple DRAM refresh and control functions Accesses to the DRAM are always multi cycle The DRAM is used for capture waterfall and trace storage These functions do not require fast multiple memory accesses Communication between the DSP and the host CPU 80C186 is handled through FIFO memories U302 U304 These are 25 ns 4k x 9 FIFO s U302 and U303 provide a 16 bit wide data path from the DSP to the host CPU This allows data to flow to the host for display as fast as
118. o do this press System to display the System menu and then press lt Preset gt and Enter to confirm The unit will perform power up tests and then assume the default settings Each test generally starts with a reset Serial Number If you need to contact Stanford Research Systems please have the serial number of your unit available The serial number is printed on a label affixed to the rear panel The serial number is also displayed on the screen when the unit is powered on SR765 Dynamic Signal Analyzer 1 4 Performance Tests Firmware Revision The firmware revision code is displayed on the screen when the unit is powered on Necessary Equipment The following equipment is necessary to complete the performance tests The suggested equipment or its equivalent should be used Frequency Synthesizer Freq Range Hz to 1 MHz Freq Accuracy better than 5 ppm Amplitude Accuracy 0 2 dB from 1 Hz to 100 KHz Harmonic Distortion lt 65 dBc Spurious lt 55 dBc Recommended SRS DS345 AC Calibrator Freq Range 10 Hz to 100 kHz Amplitude 1 mV to 10 V Accuracy 0 1 External phase locking capability Recommended Fluke 5200A Feedthrough Terminations Impedance 50 Q Warm Up The analyzer should be turned on and allowed to warm up for at least an hour before any tests are performed The self test does not require any warm up period It is necessary to turn the unit off and on to reset it As long as the unit is powered within a m
119. og input board The DIG power drives the DSP board If removing a board fixes the supply voltage then proceed to replace the suspect board or assembly If nothing seems to help contact Stanford Research Systems or an authorized representative Service Procedure B1 Replacing the CRT Service Guide 1 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Release the CRT connector cable from the System backplane behind the CRT enclosure The CRT enclosure is secured by four screws two on the left and two on the right These screws are in slots in the enclosure Remove these screws Slide the CRT enclosure back until the front clears the front panel bezel Lift the enclosure up and out it s heavy Lower the new CRT enclosure into the chassis and slide it forward Make sure that the slots in the enclosure overlap the mounting screw holes along the sides Insert the four screws which secure the enclosure Do not tighten them Gently slide the CRT enclosure forward until the front of the CRT just touches the plastic anti glare screen Slide the CRT back 1 8 so that the front of the CRT is just behind the anti glare screen Tighten the four screws to secure the enclosure in place SR785 Dynamic Signal Analyze
120. ole Pkg Z0 0 00121 050 2 1 2 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00127 050 4 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z0 0 00168 023 6 32X5 16R Screw Roundhead Phillips Z0 0 00187 021 4 40X 1 4PP Screw Panhead Phillips Z0 0 00231 043 4 SHOULDER Washer nylon Z0 0 00244 021 6 32X1 1 8PP Screw Panhead Phillips Z0 0 00316 003 PLTFM 28 Insulators Z0 0 00373 000 CARD EJECTOR Hardware Misc Z0 0 00509 000 60MM 12V Hardware Misc Z0 1 00002 113 10 PIN 18AWG OR Connector Amp MTA 156 Z0 1 00033 113 5 PIN 18AWG OR Connector Amp MTA 156 Z0 6 00179 615 MAP55 4000 Power Supply Z0 7 00541 720 SR780 27 Fabricated Part SR785 Dynamic Signal Analyzer Service Guide System Backplane Parts List Parts Lists 4 11 This section covers schematics MBKPL 20 through MBKPL 23 in Chapter 5 System Backplane Assembly Ref No SRS Part No Value Component Description JPIA 1 00237 108 120 PIN VERTICA DIN Connector Female J2A 1 00240 108 96 PIN RT ANGLE DIN Connector Female JP3A 1 00016 160 RS232 25 PIN D Connector D Sub Right Angle PC Female JP4A 1 00272 130 34 PIN DI Connector Male JP5A 0 00112 053 1 3 4 24R Wire 24 UL1007 Strip 1 4x1 4 Tin JP6A 0 00112 053 1 3 4 24R Wire 24 UL1007 Strip 1 4x1 4 Tin JP10A 1 00237 108 120 PIN VERTICA DIN Connector Female JP11A 1 00238 161 GPIB SHIELDED Connector IEEE488 Reverse R A Female JP12A 1 00016 160 RS232 25 PIN D Connector D Sub Right
121. ole Pkg U 605 3 0021 1 340 LT1016 Integrated Circuit Thru hole Pkg U 606 3 00087 340 LF347 Integrated Circuit Thru hole Pkg U 607 3 00241 340 AD7528JN Integrated Circuit Thru hole Pkg U 608 3 00116 325 78L05 Transistor TO 92 Package U 610 3 00116 325 78L05 Transistor TO 92 Package U 611 3 00122 325 79L05 Transistor TO 92 Package U 612 3 00262 340 74HC86 Integrated Circuit Thru hole Pkg U 613 3 00491 340 UPD71054C Integrated Circuit Thru hole Pkg U 614 3 00404 340 74HC107 Integrated Circuit Thru hole Pkg U 615 3 00155 340 74HC04 Integrated Circuit Thru hole Pkg U 616 3 00861 343 SR785 U616 GAL PAL I C U 701 3 00855 343 SR785 U701 GAL PAL I C U 702 3 00856 343 SR785 U702 GAL PAL I C U 703 3 00857 343 SR785 U703 GAL PAL I C U 704 3 00863 343 SR785 U704 GAL PAL I C U 705 6 00110 621 30 208 MHZ Crystal Oscillator U 706 6 00181 621 30 933 MHZ Crystal Oscillator U 707 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 708 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 709 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U 710 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg U711 3 00603 340 T4ALS573 Integrated Circuit Thru hole Pkg U712 3 00584 340 7AACT574 Integrated Circuit Thru hole Pkg U 713 3 00584 340 7AACT574 Integrated Circuit Thru hole Pkg U714 3 00862 343 SR785 U714 GAL PAL I C U 716 3 00584 340 T4ACTS74 Integrated Circuit Thru hole Pkg U 720 3 00274 340 7AAC74 Integrate
122. or Ceramic 50V 80 20 Z5U AX C 928 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 929 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 930 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 931 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 932 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 933 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 934 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 935 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 936 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX SR765 Dynamic Signal Analyzer Service Guide Parts Lists 4 15 DSP Board Assembly Ref No SRS Part No Value Component Description C 937 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 938 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 939 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 940 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C941 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 942 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 943 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 944 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 945 5 00225 548 LU AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 946 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U
123. or Tantalum 35V 20 Rad C521 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 522 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 523 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 524 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 525 5 00023 529 IU Cap Monolythic Ceramic 50V 20 Z5U C 526 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C531 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 532 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 533 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 534 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C541 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 542 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 543 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 544 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C551 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 552 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 601 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C 690 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 691 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 692 5 00023 529 AU Cap Monolythic Ceramic 50V 20 Z5U C701 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad D101 3 00004 301 1N4148 Diode D 102 3 00004 301 1N4148 Diode D 103 3 00004 301 1N4148 Diode D 104 3 00004 301 1N4148 Diode D 105 3 00004 301 1N4148 Diode D 106 3 00004 301 1N4148 Diode D 107 3 00004 301 1N4
124. osition and insert the correct fuse into the fuse holder Verify that the correct fuse is installed For 100V 120V use a 1 5 A fuse For 220V 240V use a 3 4 A fuse Use the DVM to verify that the fuse is not blown or damaged Disconnect the power cord Use the DVM to check that the GND test point on the Power Supply board is connected to the chassis and also to the ground pin of the power entry module The GND test point is at the top edge of the board directly behind the notch If GND is not shorted to chassis or power ground check the GND green wires on the rear panel chassis ground connection above the power switch on the inside One green wire connects directly to the power entry module ground the other to the System backplane via the AC power connector SR785 Dynamic Signal Analyzer 3 12 Service Do not continue if there is a fault in the chassis or power STOP grounds 7 Connect the power cord and turn the power ON The fans should turn and the red LED at the top of the board should be ON If the fans do not turn or the LED stays off turn the power OFF and remove the power cord Check the AC power connector and transformer connector integrity You may need to remove the Power Supply board to do this See Procedure A1 for details on removing the Power Supply board 8 Check the voltages on the power supply test points This procedure measures the supply voltages under load all other boards are present and with all grounding
125. ower is turned on Yes see Display Problems e After reset is there a signal at the Source Output Yes see Display Problems Proceed to Service Procedure A2 Power Supply Check If the Power Supply is OK see Display Problems Display Problems s the screen brightness turned down Press the Brighter button at the lower right of the screen below the softkeys s the display unstable Yes proceed to Service Procedure B2 CRT Check e Is the display blank Yes proceed to Service Procedure B2 CRT Check e If there still a problem proceed to Service Procedure D3 Video IO Board Replacement Keypad not functioning e Is there a key stuck in the down position Yes release the stuck key Proceed to Service Procedure C1 Keypad Check Knob not functioning Proceed to Service Procedure C2 Knob Check System lt Diagnostics gt e Proceed to Service Procedure D1 CPU Board System RAM check fails Replacement System lt Diagnostics gt e Contact SRS for replacement ROM components If System ROM check or failure continues proceed to Service Procedure D1 CPU Help ROM check fails Board Replacement System lt Diagnostics gt e Proceed to Service Procedure D3 Video IO Board Video RAM check fails Replacement Unit does not recall Proceed to Service Procedure D2 Battery Check settings at power on Clock does not keep Proceed to Service Procedure D2 Battery Check time correctly
126. p If the reading is greater than 85 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 8 3 15 Press 16 17 18 19 Input Input Config Channel Select Ch1 Ch2 Enter Chl Input Range Ch2 Input Range 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Low Gain Offset pot to minimize the marker reading see Fig 8 3 This completes the adjustment procedure Replace the small shield at the front Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws Reset the unit by turning the power ON while holding down the backspace key If the DC offset or Common Mode Rejection are still a problem repeat this procedure one more time Otherwise follow Procedure F2 to replace the Analog board SR765 Dynamic Signal Analyzer Service Guide Chapter 4 Parts Lists 4 1 This chapter lists the components on the major circuit assemblies in the SR785 The schematics for each board are shown in Chapter 5 In This Chapter CPU Board Parts List Video IO Board Parts List Power Supply Board Parts List System Backplane Parts List Disk Card Parts List DSP Board Parts List Analog Input Board Parts List Analyzer Backplane Parts List
127. pad Interface The keypad is organized as 8 columns and 8 rows of switch closures The conductive rubber keys provide the switch closures U607 strobes the columns and U606 detects the switch closure The diodes D601 D608 prevent one column from affecting another All of the outputs from U607 are set high and U606 is read periodically by the processor As long as OOH is read no key is pressed and the strobes are left on When a non zero value is read then the key strobes are activated individually in order to decode which key is down Spin Knob The knob is an optical encoder buffered by U612 Each transition of its quadrature outputs is clocked into U610 or U611 and generates an interrupt at the output of U507B The processor keeps track of the knob s direction and speed Keyboard Interface The PC keyboard interface uses U603 to convert serial data from the keyboard into a parallel byte for the processor to read The data format from the keyboard is a leading start bit followed by 8 data bits U603 is reset by a processor read When a key is pressed the bits are shifted into U603 When the start bit appears at the QH output 7 bits of the data byte are in U603 U601 is the 9th bit of the shift register When U601 clocks in the start bit U601 must have the 8 bits of the data U601 then latches the serial data in U601 and interrupts the processor Only keyboards which operate in the PC or 8088 mode will function with this interface Speaker The
128. plitude in the table b Press Start Reset and wait for the average to finish c Record the marker Y reading for both displays 4 This completes the amplitude linearity test Enter the results of this test in the test record at the end of this section SR785 Dynamic Signal Analyzer Performance Tests 1 19 6 Anti alias Filter Attenuation This test measures the attenuation of the anti alias filters This tests how well the analyzer rejects frequencies outside the 102 4 kHz frequency range Setup We will use the frequency synthesizer to provide the signal Connect the output of the frequency synthesizer to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 160 144 kHz and an amplitude of 500 mVrms 3 Press the keys in the following sequence Freq lt Span gt 8 0 0 Select Hz Enter lt Center Freq gt 1 0 2 Select kHz Enter Input lt Input Config gt lt Channel gt Select Both Enter lt Ch1 AA Filter Select Off Enter Average lt Averaging Type gt Select Linear Fix Len Enter lt Avgs gt 1 0 Enter lt Display Avg gt Select On Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B SR765 Dynamic Signal Analyzer 1 20 Performance Test
129. possible U304 provides an 8 bit data path from the host CPU to the DSP for commands and data The FIFO s allow the sender and the receiver to run at their full rates without waiting for the other The DSP can interrupt the host by raising the 186INTO line output from port U710 and latching the request in U720A The host clears the interrupt by writing to address INTO CLR decoder U805 The host CPU can interrupt the DSP via IRQ3 by writing to ports in U805 These interrupts are generally used by the sender to signal that a FIFO is full and the receiver should read the FIFO Timing Signal Generator The timing signal generator provides all timing signals for the A D and D A Converters and their corresponding serial ports The master clock is chosen from either U705 30 208 Mhz or U706 30 933 Mhz U706 is used if the FFT Base Frequency is 102 4 kHz and U705 is used if the FFT Base Frequency is 100 0 kHz U701 U703 implement a 118 state 7 bit counter The state machine generates the convert clocks frame sync and bit clocks for the converters U716 re synchronizes the clock signals and drives the off SR765 Dynamic Signal Analyzer Service Guide Circuit Description 2 13 board signals to the Analyzer backplane U712 latches the state of the timing generator when a trigger signal is detected The timing generator interrupts the DSP whenever the serial ports A D and D A are ready every sample time The trigger is also synchronized to th
130. present within the unit USE CAUTION Use caution when checking circuits with the power on Always disconnect the power cord before replacing or servicing any component inside the chassis Required Equipment 1 DC AC Voltmeter DVM 5 1 2 digit accuracy True RMS AC to 100 kHz Recommended Fluke 8840A with Option 09 or equivalent Frequency Synthesizer function generator 1 Hz to 100 kHz 0 2 dB amplitude accuracy Recommended SRS DS335 or equivalent Philips screwdrivers various sizes Slot head screwdrivers various sizes Hex keys various sizes Oscilloscope 10 MHz bandwidth or greater Service Procedure A1 Power Supply Board Replacement 1 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards SR785 Dynamic Signal Analyzer Service Guide Service 3 11 See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place Remove the two screws which secure the power supply shield to the rear panel These are located on the rear panel directly in back of the power supply board Remove the Power Supply board by using the card ejectors to release the board and pull th
131. r 3 14 Service 9 Connect the CRT cable to the System backplane behind the CRT enclosure Make sure that the cable is locked into place 10 Replace the top lid and refasten the eight lid screws Service Procedure B2 CRT Check 1 Turn the power OFF M 2 Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards 3 Turn the power ON Use the DVM to check the 12V power supply to the CRT See Figure 8 1 to locate the Power Supply board Measure the 12V test point on the Power Supply board relative to the chassis The voltage should be within 5 of nominal If the 12V supply is fine proceed to Procedure B1 and replace the CRT assembly 4 Ifthe 12V supply is not within nominal check the supply voltage without the CRT connected Turn the power OFF Remove the CRT cable from the connector on the System backplane behind the CRT enclosure Turn the power back ON Measure the 12V test point on the Power Supply board relative to the chassis The voltage should be within 5 of nominal If the 12V supply is fine proceed to Procedure B1 and replace the CRT assembly If the 12V supply is still not within nominal turn the power OFF replace the CRT cable and proceed to Procedure A1 Power Supply Replacement Service Procedure C1 Keypad Check 1 Perform the Keypad check in the System lt Di
132. r Metal Film 1 8W 1 50PPM R 637 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 640 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 645 4 00241 407 787 Resistor Metal Film 1 8W 1 50PPM R 646 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 647 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 648 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 649 4 00702 407 1 78K Resistor Metal Film 1 8W 1 50PPM R 660 4 0078 1 402 56 Resistor Carbon Comp 1 2W 5 R 661 4 0078 1 402 56 Resistor Carbon Comp 1 2W 5 R 670 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 671 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 672 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 673 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 679 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R 701 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 702 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 703 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 704 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 705 4 00471 401 82 Resistor Carbon Film 1 4W 5 R 706 4 00038 401 120 Resistor Carbon Film 1 4W 5 R 707 4 00038 401 120 Resistor Carbon Film 1 4W 5 R 708 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 709 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 901 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 SO101 1 00231 150 PGA 223 PIN Socket THRU HOLE SO715 1 00156 150 32 PIN 600 MIL Socket THRU HOLE T
133. rameters and functions These keys are not in a menu since they are used frequently and within any menu The FUNCTION keys perform common functions such as Auto Scale and Auto Range These keys can be accessed at any time lt Softkeys gt Knob Reset The SR785 has a menu driven user interface The Menu keys each display a menu of softkeys The softkeys are at the right of the video display and have different functions depending upon the displayed menu Softkeys are referenced in brackets like lt Span gt or lt Units gt There are three types of softkeys buttons lists and numeric values A button performs a function such as lt Full Span gt A list presents a list of choices or options in the entry field at the top of the screen Use the knob to make a selection and press Enter lt Measurement gt is an example of a list A numeric value presents the current value in the entry field and awaits numeric entry Enter a new value with the entry keys and press Enter lt Start Freq gt is an example of a numeric value The knob normally moves the markers within the displays If a parameter has been highlighted by its softkey the knob adjusts the parameter List parameters are most easily modified with the knob Numeric parameters may also be adjusted with the knob Knob list selections are referenced in parenthesis like Hanning Throughout this section it will be necessary to reset the analyzer into a known default state T
134. re D1 CPU Board Replacement SR765 Dynamic Signal Analyzer Service Guide Service 3 7 Symptoms Unit displays an active Apply a known 10 kHz 0 5 Vrms sine wave to the A baseline spectrum but no input of the non functioning channel Does the signal signal appear in the spectrum No proceed to Service Procedure F3 Checking the Analog Inputs Does the unit pass the DSP memory checks Use System lt Show Version gt to review the power on test results No see DSP memory check fails Does the unit pass the Analog board memory checks Use System lt Show Version gt to review the power on test results No see Analog memory check fails No data graphed in the Does the unit pass the DSP memory checks Use displays System lt Show Version gt to review the power on test results No see DSP memory check fails Proceed to Service Procedure D1 CPU Board Replacement Input problems Apply a known 10 kHz 0 5 Vrms sine wave to the A coupling grounding or input of the non functioning channel Does the signal input range appear in the spectrum No proceed to Service Procedure F3 Checking the Analog Inputs Proceed to Service Procedure F2 Analog Board Replacement Measured amplitude of Proceed to Service Procedure F4 Amplitude Check signal not correct Unit does not trigger or Proceed to Service Procedure F5 Trigger Check trigger is unstable when in triggered mode Large DC offset on Proceed to Se
135. read at power on and does not contribute digital noise to this board Several voltages are generated on the Analog Input board locally 15 V is generated for most of the analog IC s U531 U532 A dedicated 15 V supply is also generated for the front end amplifier U501 U502 5 V is generated for the A D Converter U521 U522 as well as a digital 5 V for the digital I O U690 Analog 6 V is generated for the analog switches U541 U542 12V is provided for the relays U551 U511 provides the high voltage bias for the ICP supply The 20 VDC supply which is the source of most of the power supplies is not grounded at the power supply It is grounded by the Analog Input board to reduce ground loops at the analog inputs Thus the 20 VDC floats when no Analog Input boards are present If either Analog Input board is present then this supply is grounded SR785 Dynamic Signal Analyzer 2 18 Circuit Description SR785 Dynamic Signal Analyzer Service Guide Chapter 3 Service 3 1 This chapter provides a troubleshooting guide with service procedures to debug and repair this unit at a board or assembly level In This Chapter Before Proceeding With Service Warranty Service CAUTION Reset Calibration Troubleshooting Table Circuit Board Locations System Components Analyzer Components Schematic Diagram Locations Service Procedures Caution Required Equipment Service Procedure Al Power Supply Board Replacement Service
136. rvice Procedure J1 Adjusting DC Offset spectrum and CMR Common Mode Proceed to Service Procedure J1 Adjusting DC Offset Rejection problem and CMR Updated ROMS are Proceed to Service Procedure D1 CPU Board available Replacement for program ROMS U301 306 and Help ROMS U801 U802 Proceed to Service Procedure F1 DSP Board Replacement for theDSP ROM Service Guide SR785 Dynamic Signal Analyzer 3 8 Service Circuit Board Locations The SR785 s circuitry is divided into two major sections the system section and the analyzer section The system section contains the main processor CPU video display external interfaces power supply and front panel The analyzer section contains the digital signal processor DSP source output and analog inputs System Components The system section components are located in the left half of the chassis behind and below the CRT video display The card cage behind the CRT contains the power supply main CPU card and the video IO card The cards are interconnected by a backplane board under the card cage The disk drive is mounted to a small board beneath the CRT This card can be removed from the front The keypad connects to the disk board at the front of the chassis Figure 8 1 System Components SO Chssis Top View CPU IL Power Supply System Ld SS Z Disk Card 7 NET Board Disk Drive Front SR765 Dynamic Signal Analyzer Service Guide A
137. s Link Marker Max Link Marker Ref This references the un filtered out of band signal at 160 144 kHz aliased to 102 0 kHz 4 Measure the anti alias filter attenuation Press Input lt Input Config gt lt Channel gt Select Both Enter Chl AA Filter Select On Enter Start Reset Wait for the average to finish Record the marker Y readings for both displays 5 This completes the anti alias filter attenuation test Enter the results of this test in the test record at the end of this section SR765 Dynamic Signal Analyzer Performance Tests 1 21 7 Frequency Accuracy This test measures the frequency accuracy of the analyzer This tests the accuracy of the fundamental crystal timebase inside the unit Setup We will use the frequency synthesizer to provide the signal Connect the output of the frequency synthesizer to the Ch1 A input of the analyzer Be sure to use the appropriate terminations where required Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 96 000 kHz and an amplitude of 500 mVrms 3 Press the keys in the following sequence Freq lt Span gt 2 0 0 Select Hz Enter Center Freq gt 9 6 Select KHz Enter Start Reset Auto Scale A Marker Max 4 Wait for the spectrum to settle at least 5 seconds then record the marker frequency reading for DisplayA 5 This compl
138. speaker is driven by a timer on the 80C186 The timer outputs a square wave which is enabled by U507A and drives the speaker through Q705 SR785 Dynamic Signal Analyzer Service Guide Circuit Description 2 7 Clock Calendar U702 is an MC146818 real time clock chip which keeps track of time and date The time base is a 32 768 kHz oscillator made by U706 Both U702 and U706 are battery backed up Reset Battery Switch U701 is the processor supervisor Power on reset is detected by U701 and signaled to the processor via Pwr_Reset In addition the chip enables to the battery backed up memory U401 and U402 are protected by U701 Q701 provides normal 5V power to the battery circuits when the power is on Printer Interface The printer interface is a normal Centronics style parallel port Output data is buffered by U703 an LS octal latch Output control bits are buffered by the open collector driver U704 and input control bits are discriminated by U705A and U705B Expansion Connector The 120 pin connector carries all of the necessary interconnections to the System backplane Both the Expansion and External buses are carried off board via this connector Power is also delivered through this connector Service Guide SR785 Dynamic Signal Analyzer 2 8 Circuit Description Video lO Board This section covers schematics MVID 10 through MVID 14 in Chapter 5 The Video IO board contains the display generation hardware the GPIB and RS232 inter
139. t measures the source sine output Setup Connect the Source output to the Ch1 A input Procedure 1 Reset the unit by pressing System Preset and then Enter to confirm 2 Press the keys in the following sequence Source Amplitude 1 gt 1 0 0 0 Enter On Auto Range Chl and wait until the range stops changing Auto Scale A Marker Max 3 Record the marker Y reading for DisplayA 4 Press Amplitude 1 gt 1 0 0 Enter 5 Record the marker Y reading for DisplayA 6 Press Amplitude 1 gt 1 0 Enter 7T Record the marker Y reading for DisplayA 8 Press Amplitude 1 gt 1 0 0 0 Enter SR765 Dynamic Signal Analyzer 1 30 Performance Tests 9 For each of the frequencies below perform steps 9a and 9b Frequency 20 48 kHz 40 96 kHz 61 44 kHz 81 92 kHz 99 072 kHz a Press lt Frequency 1 gt Enter the frequency from the table Marker Max b Record the marker Y reading for DisplayA 8 This completes the source sine test Enter the results of this test in the test record SR785 Dynamic Signal Analyzer Performance Tests 1 31 11 Harmonic Distortion This test measures the harmonic distortion of the analyzer source and inputs Setup Connect the source output to the Chl A and Ch2 A inputs of the analyzer Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm This sets the source to sine output at 10 24 kHz and 500 mVpk
140. t panel clock and printer port PCS1 enables the peripherals on the Video IO board PCS2 enables the AUX connectors on the System backplane PCS1 and PCS2 enable the Expansion data bus PCS4 and PCS5 enable the External DSP bus PCS4 enables processor addressable peripherals on the DSP board SR785 Dynamic Signal Analyzer 2 6 Circuit Description U501 and U503 decode the on board I O locations enabled by PCSO These are the knob keypad and keyboard the clock the printer port and the system status port U508 is a wait state generator Extra wait states are generated by all I O accesses These extra wait states are canceled if the access is to the External bus The Video_Rdy signal also ends the wait generation Video_Rdy signals that the graphics processor on the Video IO board has acknowledged an IO cycle and is ready Interrupts generated by system peripherals on both the CPU and Video IO boards are combined in U505 into a single prioritized interrupt The highest priority pending interrupt will be encoded on U505 s outputs and read via the status port U608 The UART directly interrupts the processor since it can never be masked String ROM U801 and U802 are 256 kbyte EPROMS containing the on screen help information These memories are mapped into the upper 32k of I O space One of the sixteen 32k banks is selected by BA15 BA18 set in the system status port This keeps ROM data from using up program memory space Key
141. talum 35V 20 Rad C 970 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C971 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 972 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX D 601 3 00004 301 1N4148 Diode D 602 3 00004 301 1N4148 Diode D 603 3 00004 301 1N4148 Diode D 604 3 00004 301 1N4148 Diode D 605 3 00004 301 1N4148 Diode D 606 3 00004 301 1N4148 Diode D 607 3 00004 301 1N4148 Diode D 608 3 00004 301 1N4148 Diode D 702 3 00004 301 1N4148 Diode D 703 3 00004 301 1N4148 Diode D 704 3 00004 301 1N4148 Diode D 705 3 00004 301 1N4148 Diode J901 1 00236 109 120 PIN RT ANGL DIN Connector Male N 101 4 00707 425 2 2KX7 Resistor Network SIP 1 4W 2 Common N 201 4 00852 420 82X8 Resistor Network DIP 1 4W 2 8 Ind N 202 4 00852 420 82X8 Resistor Network DIP 1 4W 2 8 Ind N 203 4 00852 420 82X8 Resistor Network DIP 1 4W 2 8 Ind N 204 4 00707 425 2 2KX7 Resistor Network SIP 1 4W 2 Common N 205 4 00422 421 82X5 Res Network SIP 1 4W 2 Isolated N 501 4 00261 425 2 2KX9 Resistor Network SIP 1 4W 2 Common N 601 4 00261 425 2 2KX9 Resistor Network SIP 1 4W 2 Common N 602 4 00220 420 10KX8 Resistor Network DIP 1 4W 2 8 Ind N 603 4 00244 421 10KX4 Res Network SIP 1 4W 2 Isolated N 701 4 00856 421 1 0KX5 Res Network SIP 1 4W 2 Isolated PCI 7 00522 701 MEGAPLAT CPU Printed Circuit Board Q701 3 00022 325 2N3906 Transistor TO 92 Package Q 705 3 00022 325 2N3906 Transistor TO 92 Pac
142. this section The computer interface and disk drive tests are not required but should be periodically checked See the System menu for more information about those tests Setup No external setup is required for this test Procedure 1 Reset the unit by pressing System Preset and then Enter to confirm During re boot the DSP memory and calibration tests should all be OK To review this power on screen use System Show Version 2 Press the keys in the following sequence SR765 Dynamic Signal Analyzer 1 8 Performance Tests System lt Diagnostics gt lt Keypad Test gt Press all of the front panel keys until all of the boxes are filled in Then press any key to exit this screen lt Knob Test gt Rotate the knob to verify rotation and direction lt Return gt lt Memory gt lt System RAM gt lt Begin gt All of the system memory chips should Pass lt Return gt lt System ROM gt lt Begin gt All of the system memory chips should Pass lt Return gt lt Video RAM gt lt Begin gt All of the video memory chips should Pass lt Return gt lt Help ROM gt lt Begin gt All of the memory chips should Pass lt Return gt lt Return gt 3 This completes the functional hardware tests Enter the results of this test in the test record at the end of this section SR785 Dynamic Signal Analyzer Performance Tests 1 9 2 DC Offset This test measures the DC offset of the input Setup
143. two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place SR785 Dynamic Signal Analyzer 3 18 Service 8 9 See Figure 8 1 to locate the Video IO board it s farthest from the Power Supply board Remove the Video IO board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Replace the bar which secures the boards in place Replace the top lid and refasten the eight lid screws 10 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F1 DSP Board Replacement 1 9 Before replacing the DSP board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 8 1 to locate the Power Supply board Make sure that the red LED
144. ue Component Description C 603 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL C 604 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL C 621 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 622 5 00200 532 470P Capacitor Ceramic Disc 50V 10 NPO C 623 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL C 624 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL C 628 5 00200 532 470P Capacitor Ceramic Disc 50V 10 NPO C 629 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 630 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 631 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 632 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U C 640 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 650 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 651 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 652 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 653 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 654 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 655 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 656 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 657 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 658 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 659 5 00093 517 15U Capacitor Tantalum 35V 20 Rad C 660 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 661 5 00098 517 10U Capacitor Tantalum 35V 20 Rad C 662 5 00100
145. whenever there is bus activity addressed to the unit RS232 Interface The SCN2641 UART U1303 provides all of the UART functions including baud rate generation Standard baud rates up to 19 2k can be generated from the 3 6864 MHz clock U1305 buffers the outgoing data and control signals Incoming signals are received by U1304 The RS232 port is a DCE and may be connected to a PC using a standard serial cable not a null modem cable Expansion Connector The 120 pin connector carries all of the necessary interconnections to the System backplane Power is also delivered through this connector Peripherals on this board are accessed whenever PCS1 from the CPU is active U1401 and U1402 provide on board decoding Service Guide SR785 Dynamic Signal Analyzer 2 10 Circuit Description Power Supply Board This section covers schematics MPWR 1 through MPWR 2 in Chapter 5 Caution Dangerous voltages are present on this circuit board whenever the instrument is attached to an AC power source and the rear panel power switch is ON Always disconnect the power cord and wait at least one minute before opening the unit Check the LED at the top edge of the power supply board The unit is safe only if the LED is OFF If the LED is ON then DO NOT attempt any service on the unit Removing the Power Supply Never remove or replace this board when the power cord is attached The Power Supply Board is held in by two rear panel screws which
146. y Ref No SRS Part No Value Component Description R 278 4 00200 407 619 Resistor Metal Film 1 8W 1 50PPM R 279 4 00279 407 3 09K Resistor Metal Film 1 8W 1 50PPM R 280 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 281 4 00748 408 2 000K Resistor Metal Film 1 8W 0 1 25ppm R 282 4 00134 407 1 24K Resistor Metal Film 1 8W 1 50PPM R 283 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 284 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 285 4 00142 407 100K Resistor Metal Film 1 8W 1 50PPM R 290 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 291 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 292 4 00031 401 100 Resistor Carbon Film 1 4W 5 R 293 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 294 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 295 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 296 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 297 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 298 4 00030 401 10 Resistor Carbon Film 1 4W 5 R 310 4 00896 407 60 4K Resistor Metal Film 1 8W 1 50PPM R311 4 00547 407 18 2K Resistor Metal Film 1 8W 1 50PPM R 312 4 00705 407 5 62K Resistor Metal Film 1 8W 1 50PPM R 313 4 00705 407 5 62K Resistor Metal Film 1 8W 1 50PPM R314 4 00896 407 60 4K Resistor Metal Film 1 8W 1 50PPM R 315 4 00363 407 21 5K Resistor Metal Film 1 8W 1 50PPM R316 4 00893 407 4 12K Resistor Metal Film

SR785 Service Manual - Stanford Research Systems

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