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Agilent Technologies Drums 2948 User's Manual

1. ew aaa 3478 Oscillo8CoD6 iara aa er HP 1740A or Tektronix 2235 Procedure 1 On the Multifunction Synthesizer connect the rear panel CLOCK SYNC OUTPUT to the rev 15DEC89 oscilloscope input Set the oscilloscope s input to 500 or terminate the input in 500 using a tee On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in SHIFT SPECIAL 7 ENTER f2 Status ON LAST f2 Status ON The oscilloscope should show a TTL waveform with a period of 74 5 ns a frequency of 13 4 MHz If faulty check the cable which terminates at A2J9 Connect the oscilloscope to A2TP1 The oscilloscope input should remain at 500 Connect short BNC cable between the rear panel CLOCK SYNC OUTPUT and CLOCK SYNC INPUT The oscilloscope display should be the same as in step 3 If faulty check the cable which terminates at A2J10 Connect the oscilloscope input or a logic probe to the RESET OUTPUT If an oscilloscope is used set it to single trigger On the Multifunction Synthesizer press f4 Exit Key in SHIFT RESET several times and observe the oscilloscope or the logic probe The logic probe should blink a high each time The oscilloscope should trigger a sweep each time It may be necessary to adjust the oscilloscope s trigger level and the trigger may need to be armed each time If faulty che
2. oe aes 8 1 Safety dea eto ave be oe Pelee qe beh 8 1 Service Tools Helps and Information 8 3 Printed Circuit Board Extractor 8 3 Assembly Parts and Cable Locations 8 3 Other Service Documients aca i yi ees Rol ee ah ee ee ets 8 3 Recommended Test Equipment and Accessories 8 3 Schematic Symbology and Schematic Diagram 8 3 Principles of Operations 4 3 dax AY wee ete Re wd as 8 15 Overall 2 sol See megs Sea EM EE ERU eus erie eS cere eh ee 8 15 A2 Digital Assembly sine r sc gods wai BA wee be e 8 23 Output Assembly Service Sheets 1 through 4 8 24 Troubleshooting ae ea M Base es eee 8 29 Generals 22 Sof d Xe Ea bce M Bee eae ee 8 29 A2 Digital Assembly to or A10 Output Assembly 8 30 A2 Digital Assembly to Al Keyboard Assembly Interface 8 38 A2 Digital Assembly to 5 Display Assembly 8 41 A10 Output Assembly ereen eos mU ER ow e edb Se SE ee ES 8 42
3. 7 5 Description zx vu a esas Se ede ec 7 5 Parts Required A Sr AV Daw eee a 7 5 Tools Required a ra Ruth eee ele aw ede te UR ee 7 5 Modification Procedure 7 5 Operation Verification e e e id ah PSR Ge EU A e o ee d 7 6 Firmware Updates A2U12 and A2UT8 oo e 7 9 Modification For Possible Ground Wire Shock 7 10 Modification For Output Overvoltage Protection Improvement 7 13 Modification For Potential Power Supply 7 14 Cabinet Parts Color 7 14 Modification For Front Panel Assembly 7 15 Model 8904A Instrument Changes Section 7 INSTRUMENT CHANGES 7 1 INTRODUCTION TO THIS SECTION This section contains instrument modification recommendations and procedures that could improve the performance and reliability of your instrument Refer to Instruments Covered by This Manual in section 1 of the HP 8904A Operation and Calibration Manual for important information about serial number coverage 7 2 OPTION CONVERSIONS It is sometimes desirable to add or delete options in the instrument after the init
4. 88 Contents Model 8904A Section 8 Service cont d How to Restore the Serial Number in a Replacement Digital Assembly 8 43 How to Restore Options 001 and 003 in a Replacement A2 Digital Assembly 8 46 How to Replace the Memory Backup Battery 8 48 1 Service Sheets 1 through 4 schematics 8 50 rev 200CT88 Model 8904A Replaceable Parts Section 6 REPLACEABLE PARTS 6 1 INTRODUCTION TO THIS SECTION This section contains information for ordering parts Table 6 1 lists reference designations and Table 6 2 lists abbreviations that are used in the Replaceable Parts List Table 6 3 lists all replaceable parts in the instrument Table 6 4 contains the names and addresses that correspond to the manufacturer s code numbers listed in Table 6 3 Also included in this section are drawings to aid in identifying and ordering chassis mounted parts and mechanical parts 6 2 REFERENCE DESIGNATIONS AND ABBREVIATIONS USED IN THIS MANUAL Table 6 1 lists the reference designation letters for electrical parts in the instrument The letter designations found in Table 6 1 are coupled with numeric designations to provide a unique reference designation for each part in the instrument For example is the reference designation of a particular resistor 1 on assembly Designators with no letter are mechanical parts Tabl
5. 415 416 417 ASCR418 A3CR419 A3CR420 421 422 A3CR423 424 A3CR425 426 A3CR427 A3CR428 TRefer to Section 7 for update information rev 17MAY88 HP Part Number 1901 0050 1901 0050 1901 0028 1901 0028 1901 0518 1901 0518 1901 0518 1901 0518 1901 0050 1901 0050 1901 0050 1902 0627 1901 0518 1901 0050 1901 0050 1901 0050 1901 0050 1901 0050 1901 0050 1901 0873 1901 0873 1901 0873 1901 0873 1901 0050 1901 0050 1901 0050 1901 0050 1901 0880 1901 0880 1901 0880 1901 0880 1901 0050 1901 0050 1901 0050 1901 0050 1902 0627 1902 0627 1902 0627 1902 0627 1901 0050 1901 0050 Mo oM oM wow oa to Table 6 3 Replaceable Parts Description NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS 00 35 DIODE SWITCHING 80V 200MA 2NS DO 35 NOT ASSIGNED DIODE PWR RECT 400V 750MA DO 29 DIODE PWR RECT 400V 750MA DO 29 NOT ASSIGNED DIODE SM SIG SCHOTTKY DIODE SM SIG SCHOTTKY DIODE SM SIG SCHOTTKY DIODE SM SIG SCHOTTKY NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS 00 35 NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE CUR RGLTR 1N5312 100V DO 7 DIODE SM SIG SCHOTTKY NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 20
6. 4 0160 4832 4 CAPACITOR FXD O1UF 10 100VDC CER 28480 0160 4832 5 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC 28480 0160 4832 A3C7 NOT ASSIGNED 0160 4535 4 9 CAPACITOR FXD 1UF 10 CER 28480 0160 4535 9 ASSIGNED 10 0160 4535 4 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4535 11 0160 4535 4 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4535 12 0160 4535 4 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4535 13 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC 56289 1500685 903582 14 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC 6289 1500685 903582 A3C15 27 NOT ASSIGNED 28 0160 0575 4 1 CAPACITOR FXD 047UF 20 50VDC CER 28480 0160 0575 29 0160 6875 9 1 CAPACITOR FXD 850PF 1 100VDC 28480 0160 6875 0160 6876 0 1 CAPACITOR FXD 7200PF 1 100VDC 28480 0160 6876 A3C31 0160 6877 1 1 CAPACITOR FXD 64PF 1 100VDC CER 0 30 28480 0160 6877 3 32 0160 6878 2 1 CAPACITOR FXD 293PF 1 100VDC CER 28480 0160 6878 A3C33 0160 3879 7 5 CAPACITOR FXD 01UF 20 100VDC CER 28480 0160 3879 A3C34 0160 6880 6 1 CAPACITOR FXD 584PF 1 100VDC CER 28480 0160 6880 A3C35 0160 6881 7 1 CAPACITOR FXD 1360PF 1 100VDC CER 28480 0160 6881 A3C36 0160 6882 8 1 CAPACITOR FXD 1290PF 1 100VDC CER 28480 0160 6882 A3C37 0160 6883 9 1 CAPACITOR FXD 438PF 1 100VDC CER 28480 01
7. Filter Select AMPTD 10V 625 mV 10V 2 5V 10V 5V SHIFT OUTPUT 1 ON SHIFT OUTPUT 1 OFF AMPTD 10V 39 mV SHIFT FLOAT 1 ON SHIFT FLOAT 1 OFF A10 Key Sequence SHIFT FILTER 2 f1 f1 Filter Select AMPTD 10V 625 10V 2 5V 10V 5V SHIFT OUTPUT 2 ON SHIFT OUTPUT 2 OFF AMPTD 10 V 39 mV SHIFT FLOAT 2 ON SHIFT FLOAT 2 OFF Troubleshooting Digital Output Interface A3 A10 Connection 8 35 Service Model 8904A 6 Overvoltage Control Checks a On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in For A3 Output Assembly For A10 Output Assembly SHIFT SERVICE SHIFT SERVICE NEXT NEXT NEXT NEXT 3 Memory Map Access f3 Memory Map Access NEXT NEXT NEXT NEXT NEXT NEXT NEXT NEXT NEXT 80 80 b Connect a dc coupled high impedance oscilloscope or logic probe to pin 12 of U2 The voltage should be a TTL low c Press SHIFT The voltage should be a TTL high NOTE To repeat this part of the check key in 80 then SHIFT A beep will be heard each time 80 is keyed in d Connect the oscilloscope or logic probe to pin 11 of U2 e Key in 80 then SHIFT As the shift key is pressed the steady state TTL high should go momentarily low then back to high The logic probe should blink The trace on an oscilloscope should blink perceptibly or if the oscilloscope is in the normal trigger mode a single sweep should be triggered f Press SHIFT PRESET After t
8. 28480 06540 06540 06540 06540 06540 06540 Factory Selected Component Refer to Section 5 Model 8904A Mfr Part Number 0515 1234 AD44H AD44H AD44H AD44H 5021 8415 0515 1860 0515 1860 0515 1860 0515 1860 0515 1860 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 08904 61013 2190 0585 0515 0955 19666 0056 19666 0056 19666 0056 19666 0056 19666 0056 19666 0056 Errata part change rev 01NOV89 Model 8904A Reference HP Part Designation Number D 120 0380 1914 3 121 0380 1929 0 1 122 1400 0249 0 1 123 7120 4295 6 1 124 1400 0249 0 1 125 1400 0249 0 1 126 1400 0249 0 1 127 1400 0249 0 1 128 1400 0249 0 129 1400 0249 0 1 130 08904 61013 8 1 131 0515 1851 4 1 132 0515 1851 4 1 133 0515 1851 4 1 134 0515 1851 4 1 135 0515 1851 4 1 136 0515 1851 4 1 137 0515 1851 4 1 138 0515 1851 4 1 2712A to 2817 139 2822A and above 139 08904 00015 2 1 Refer to Section 7 for update information rev 01NOV89 Table 6 3 Replaceable Parts Description SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 4 MM ID 3 5MM THD ADDED FOR OPTION 002 CABLE TIE 062D 09W ADDED FOR OPTION 004 LABEL WARNING 1 IN WD 2 IN LG AL CABLE TIE 0620 09W ADDED FOR OPTION 004 CABLE TIE 0620 09W AD
9. 7 Agilent Technologies Inc www agilent com 24001 E Mission Liberty Lake WA 99019 2 Agilent Technologies E m Innovating the HP Way June 8 2000 Dear Customer As of November 1 1999 four of Hewlett Packard s businesses test and measurement semiconductor products health care solutions and chemical analysis became a new company Agilent Technologies Now many of your Hewlett Packard products and services are in the care of Agilent Technologies At Agilent Technologies we are working diligently to make this transition as smooth as possible for you However as a result of this transition the products and related documentation contained in this shipment may be labeled with either the Hewlett Packard name and logo the Agilent Technologies name and logo or a combination of both Information in this package may refer to Hewlett Packard HP but applies to your Agilent Technologies product Hewlett Packard and Agilent branded products with the same model number are interchangeable Whatever logo you see the information products and services come from the same reliable source If you have questions about Agilent Technologies products and services please visit our website at http www agilent com Sincerely Rebranding Team HP 8904A MULTIFUNCTION SYNTHESIZER Including Options 001 002 003 and 004 Service Manual SERIAL NUMBERS This manual applies directly t
10. 7 6 Rear to Front Panel Output Conversion rev 15DEC89 Model 8904A Instrument Changes Figure 7 1 Front Panel Output Hardware Figure 7 2 Rear Panel Output Hardware rev 15DEC89 7 7 Instrument Changes Model 8904A OPTION 002 REAR OUTPUT OPTION 004 STANDARD OUTPUT REAR OUTPUT OPTION 002 Figure 7 3 Output Cable Routing All Options 7 8 rev 15DECS89 Model 8904A Instrument Changes 7 6 FIRMWARE UPDATES A2U12 AND A2U13 The firmware is changed whenever anomalies are found in the instrument s operation which can be corrected by altering the Controller s program Firmware is also changed to add new features which may only be changes in the program or which may also result from instrument hardware changes Replacing the ROMs Use the following procedure to install new ROMs The ROMs 2012 2013 are static sensitive devices Take precau tions against electrostatic discharge ESD before handling these compo nents NOTE In instruments with serial prefix 2942A and below the firmware is stored in two ROMs 2012 and A2U13 In instruments with serial prefix 2948A and above the firmware is stored only in one ROM 2012 2013 serves a different function 1 Unplug the power cord 2 Remove the top cover The cover may be tightly secured in the groove of the bottom cover If the top cover does not pull off easily after backing out the screw on the rear edge back out the
11. The unity gain inverting buffer amplifier formed by U403 and U404 isolates the Floating Output Amplifier from the Sine X X Compensation The combination of resistors R412 R413 and R421 form 1 resistance which can handle the output current from the Audio Amplifier U404 is a current booster stage C401 bypasses U404 at high frequencies to stabilize the buffer at high frequencies L401 and R416 compensate the high frequency rolloff of the Floating Output Amplifier Floating Output Amplifier Service Sheet 4 The Floating Output Amplifier is a single ended to differential converter Conversion is accomplished by a precise combination of negative feedback positive feedback and cross coupling which yields a symmetrical differential output with high common mode rejection and a well defined output impedance of 500 The complexity of the circuit makes detailed analysis difficult Output transistors Q401 through Q404 boost the current drive capability of differential amplifiers U401 and U402 Constant current sources CR423 through CR426 provide bias current for diodes CR404 through CR407 and the bases of Q401 through Q404 CR423 through CR426 thermally compensate the base emitter junctions of Q401 through Q404 Q405 through Q408 shut off Q401 through Q404 when the latter transistors start drawing too much current to protect the amplifier Further protection is provided by CR408 through CR411 and CR419 through CR422 C425 equalizes the phase shift
12. 12 Remove the four Torx screws with lockwashers items 40 through 43 in figure 6 3 securing the A5 LCD Display to the old front panel and remove the display The screws will not be reused 13 Remove the four Torx screws and captive lockwashers securing the new display shield to the new front panel and temporarily remove the new display shield 14 Install the LCD display on to the new front panel securing it with the four new screws and captive lockwashers HP 0515 1851 from the kit Tighten the screws to 0 6 N m 5 in Ib 15 Re install the new display shield on to the new keyboard with the four screws and captive lockwashers removed in step 13 Alignment of the shield is critical The shield should be pulled up as high as the screw slots will allow Tighten the screws to 1 1 N m 9 inb 7 16 Firmware Updates Hardware Modifications rev 15DEC89 Model 8904A Instrument Changes Installing the Front Panel 16 Remove any existing unneeded hole plugs from the new front panel assembly 17 Install the line switch bracket supplied in the kit HP 08904 00022 item 142 in figure 7 6 Detail A herein on to the line switch using the two Pozidriv screws supplied in the kit HP 0515 2028 items 143 and 144 Tighten the screws to 0 6 N m 5 in lb 18 Install the line switch bracket on to the front frame using two of the screws items 84 and 145 in figure 7 6 securing the old front panel to the frame item 89 Do not tighten the screws a
13. rev 15DEC89 Troubleshooting Memory Backup Battery 8 48 5 Service Model 8904A LINE VOLTAGES 115VAC 252 187 238VAC 152 10 48 66HZ A 4 POWER SUPPLY ASSEMBL Y OF W 12 Figure 8 12 4 Line Voltage Wiring Harness 8 48 6 Troubleshooting Memory Backup Battery rev 15DEC89 Service Model 8904 A3 Component Coordinates 1 of 2 A3 Component Coordinates 2 of 2 TPL 2 c 38 imos per C m wa 14 Ex jum sett a s J1 J481 s sii3 2 x PL NOTES 1 2 UNUSED CIRCUITRY nk INITIAL INSTRUMENT SETTINGS VOLTAGES ON THIS SCHEMATIC UNLESS OTHERWISE al 19 02016 NOTED SHOULD BE MEASURED AFTER KEYING IN FOR A3 FOR A18 7 9 3 SHIFT PRESET SHIFT PRESET SHIFT FLOAT 1 OFF SHIFT FLOAT 2 OFF A ues 5 1 CHANNEL CONFIG gt 1 CHANNEL CONFIG gt NEXT NEXT NEXT 10 10 V NOTE 1261 1 A DIODE ARRAY CONTAINING SIX COMPONENTS 5 TP482 Figure 8 13 Service Sheet Information Component Locator 8 50 Jaca PALS 2 10 DC CONTROL 1 5 DA 32 2 CLOCKS J1 18 e DAS AC 0 10 2 41010 CONTROL 4 91011 J1013 41414 J1 28 TO
14. Al Interconnections to A2 at the end of this procedure for a cross reference of the signal interconnections Equipment Oscilloscope seisde sig goede Rr er EE eme HP 1740A or Tektronix 2235 Procedure ta Quick Key Check NOTE This check will quickly verify that the keys operate properly If this check fails run the following check to pinpoint the failure a Check that switches 1 and 2 of the Service Switch 51 on the A2 Digital Assembly are open and switches 3 through 10 are closed b On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in SHIFT SERVICE 1 Keyboard Check c Press each key and check that the name of the key which appears in the lower left hand of the display agrees with the key pressed NOTE A beep will also be heard after each keypress Press 14 twice to exit this mode 1b Key Check a Check that switches 1 and 2 of the Service Switch 51 on the A2 Digital Assembly are open and switches 3 through 10 are closed b On the Multifunction Synthesizer press SHIFT PRESET If the instrument does not preset switch LINE to OFF and then to ON If the instrument does not preset the A2 Digital Assembly or A4 Power Supply is probably faulty c After the instrument presets connect a dc coupled high impedance oscilloscope or a logic probe to the points listed in the following table and press the keys indicated When a key is pressed the logic level should
15. EE 0437 SE CENE Q N 3B 5 ER g 1 OUTPUTS w fw INITIAL INSTRUMENT SETTINGS VOLTAGES ON THIS SCHEMATIC UNLESS OTHERWISE NOTED SHOULD BE MEASURED AFTER KEYING IN 0483 FOR FOR 10 SHIFT PRESET SHIFT PRESET 2 8 SHIFT FLOAT 1 OFF SHIFT FLOAT 2 OFF nm did 1 CHANNEL CONFIG 1 CHANNEL CONFIG NEXT NEXT NEXT Service Sheet Information Component Locator P O 10 SEE REVERSE SIDE OUTPUT ASSEMBLY 553 AMPTO 18 AMPTD 18 8 56 THE VOLTAGE SHOWN THE FRONT OR REAR PANEL OUTPUTS ARE WITH OR 19 402 CONTACTS CLOSED Service Model 8904A CHANGES 2948A and above On the A3 A10 schematic e W1 J8 In the FLOATING OR GROUNDED AUDIO OUTPUT circuit block open the LOW signal line about a 0 5 inch gap just after it passes over the 5VREF Draw a jumper wire acrosse the opening and label it W1 Label the left end of the jumper J8 2 and the right end of the jumper J8 1 Draw node dot about 0 125 inch below J8 1 and label it J8 3 Connect a common ground symbol to J8 3 Write the following note directly under the circuit block Jumper J8 connects pins 1 and 2 for all instruments except when equipped with option 006 Connect J8 pins 2 and 3 for option 006 equipped instruments SS4 rev 30NOV89 8 56 1 10 4122 MISCELLANEOUS a C
16. FGND FLOATING OR GROUNDED AUDIO OUTPUT 5419 C418 P O 4 B Eres 0413 2 42 2 1589 C SEE NOTE 2 SS4 8 57 Service Mode 8904A CHANGES 2948A and above A6 Schematic and Component locator e Use the component locator on page 8 60 for the A6 High Power output assembly component locations e Use SS5 Opt 006 on page 8 61 for the A6 High Power Oustput assembly schematic information 555 15 89 8 59 Model 8904A Service Figure 8 17 Component Locator For S55 555 8 60 15 89 A6 HIGH POWER OUTPUT ASSEMBLY P O A3 A1 OUTPUT 7565 GS ads MSS Lr MC LIE R l TRANSFORMER l 19 09 RS 85 mer oso 0562 sse nec 348 Y L OUT 688 W28 455 Js os L E af we ee 1 555 6 HIGH POWER OUTPUT ASSEMBLY 886 8 61
17. Option 002 The modifications requires partial disassembly of the instrument removing covers and routing of cables No soldering is required Modification should be done in a static protected environment After modification two performance tests must be run Parts Required The following parts are required and may be ordered by contacting the nearest Hewlett Packard Sales Office Table 7 1 Parts for HP 8904A Front to Rear Panel Output Conversion Standard Plastic Hole Plug 6960 0132 Option 002 Plastic Hole Plug 6960 0132 Standard Lock Washer 0 505 inch ID 2190 0068 Option 002 Lock Washer 0 505 inch ID 2190 0068 Cable Tie 1400 0249 Label Blank 5180 1871 Tools Required The following tools are needed to modify the instrument 9 16 inch 6 point Nut Driver No 2 Pozidriv Screwdriver Diagonal Cutters Needle nose Pliers Modification Procedure Removing Bottom Cover 1 Turn the instrument off and unplug the power cord 2 Lay the instrument on its top and unscrew the Pozidriv screw in the middle of the rear edge of the bottom cover This is a captive screw and will cause the bottom cover to push away from the frame Slide the cover back about 6 5 mm 0 25 inch and lift it off Preparing the Chassis 1 Remove the nuts from the present front panel outputs with the 9 16 inch nut driver Do not press against the front panel with the tool or scoring of the panel may occur 2 Remove the cable tie around the loop of slack co
18. Screw 3 0x6 mm Panhead Torx 0515 1851 with Captive Lockwasher Screw 2 5x4 mm Flathead Pozidriv 0515 2028 Flatwasher 3 mm ID 3050 0891 Hole Plug 0 5 inch Diameter 6960 0132 Display Shield 08904 00021 Line Switch Bracket 08904 00022 Keypad 08904 40006 Keyboard Assembly A1 08904 60201 Front Panel Assembly 08904 61021 AB 2 3 4 1 1 1 1 1 orn SO INSTALLATION PROCEDURE Removing Covers CAUTION Use standard electrostatic discharge ESD precautions when working around electrostatic sensitive components such as on the display and digital assem blies NOTE Refer to the figures in Section 6 of the HP 8904A Service Manual and figure 7 6 in this installation note for part identification and location j Turn the instrument off and unplug the power cord 2 Remove the top and bottom covers by unscrewing the screw in the middle of the rear edge of the covers This is a captive screw and will cause the cover to push away from the frame rev 15DEC89 Firmware Updates Hardware Modifications 7 15 Instrument Changes Model 8904A Removing the Front Panel 3 Unplug the two connectors on the top front edge of the A2 Digital Assembly that are attached to the A5 LCD Display Refer to figure 6 3 The two cables are labeled as P O 5 4 Remove the top trim strip item 67 in figure 6 5 and two side strips items 61 and 62 from the front panel frame 5 Remove the 10 screws items 75 through 84 i
19. key in For A3 Output Assembly For 10 Output Assembly f1 Channel Config f1 Channel Config NEXT NEXT NEXT WAVE FORM 4 WAVE FORM 4 FREQ 25 6 Hz FREQ 25 6 Hz AMPTD 10 V AMPTD 10 V NOTE Setting the frequency to exactly 25 6 Hz inputs a TTL squarewave to each input of the DAC latches As the DAC s data input lines are probed from the most significant bit the the least significant bit the frequency is consecutively divided by two Connect the high impedance input of the counter to the pin of the IC listed below The counter should read within one count of the frequency indicated in the table IC on A3 or A10 EM Frequency Hz 52 428 8 26 214 4 13 107 2 6 553 6 3 276 8 1 638 4 819 2 409 6 204 8 102 4 51 2 25 6 8 34 Troubleshooting Digital Output Interface Model 8904A 5 Miscellaneous Control Checks a On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in For A3 Output Assembly f1 Channel Config NEXT For 10 Output Assembly f1 Channel Config NEXT NEXT Service b Connect a de coupled high impedance oscilloscope or logic probe to the pin of the IC listed in the table below For each connection key in the sequences listed in the table in the order listed and note the logic state Filter 24 dB Attenuator 12 dB Attenuator 6 dB Attenuator On Off Switch 48 dB Attenuator Float Ground Switch A3 Key Sequence SHIFT FILTER 1
20. 1 AUDIO TRANSFORMER 28480 9100 4833 2712A to 29174 Wi 08904 61005 8 WIRING HARNESS 28480 08904 61005 2923A and above WI 08904 61022 9 1 WIRING HARNESS 28480 08904 61022 LINE POWER A4P1 TO POWER SWITCH w2 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 A3J400 TO REAR PANEL OUT 1 HIGH w3 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 A3J401 TO REAR PANEL OUT 1 LOW w4 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 OPTION 002 004 A10J400 TO REAR PANEL OUT 2 HIGH 5 08904 61007 0 6 COAX CABLE BNC PCB REAR PANEL OUTPUT 28480 08904 61007 OPTION 002 004 A10J401 TO REAR PANEL OUT 2 LOW w6 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 400 TO FRONT PANEL OUT 1 HIGH w7 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 A3J401 TO FRONT PANEL OUT 1 LOW w8 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 ADDED FOR OPTION 002 A10J400 TO FRONT PANEL OUT 2 HIGH ws 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 ADDED FOR OPTION 002 A10J401 TO FRONT PANEL OUT 2 LOW w10 08904 61007 0 6 COAX CABLE BNC PCB 28480 08904 61007 REAR PANEL 10 MHZ EXT REF IN TO A2J101 08904 61007 0 6 28480 08904 61007 A2J102 TO REAR PANEL 10 MHZ REF OUT w12 08904 61009 3 1 LINE VOLTAGE SELECTION CABLE 28480 08904 61009 REAR PANEL VOLTAGE SELECT TO A4P4 w13 08904 61003 6 1 RIBBON CABLE 24 CONDUCTOR 28480 08904 61003 REAR PANEL HP IB FO A2J3 tRefe
21. 162DIA RIVET BLIND DR PIN DOME HD 16201 NUT SPCLY 15 32 32 THD 14N THK 562 WD BINDING POST ASSY SGL THD STUD WASHER LK INTL T 1 2 IN 505 IN ID NUT SPCLY 15 32 32 THD 1 IN THK 562 WD WASHER LK INTL T 1 2 IN 505 IN ID PLUG HOLE 500D PLUG HOLE 500D PLUG HOLE 500D PLUG HOLE 500D WASHER LK INTL T 1 4 IN 256 INID NUT HEX DBL CHAM 1 4 32 THD 094 IN THK SCREWLOCK FEMALE AMP HD CONN SCREWLOCK FEMALE AMP HD CONN WASHER LK HLCL 3 0 MM 3 1 MM ID WASHER LK HLCL 3 0 3 1 MM ID WASHER LK 505 ID ADDED FOR OPTION 004 NOT ASSIGNED WASHER LK 50540 ADDED FOR OPTION 004 NOT ASSIGNED NUT SPCL 15 32 32 ADDED FOR OPTIONS 004 AND 005 WASHER LK 505 ID ADDED FOR OPTION 004 NUT SPCL 15 92 32 ADDED FOR OPTIONS 004 AND 005 WASHER LK 505 ID ADDED FOR OPTION 004 Mfr Code 28480 28480 28480 90201 90201 90201 90201 00779 00778 78189 78189 28480 00000 28480 28480 00000 28480 28480 28480 28480 28480 28480 00000 00779 00779 28480 28480 00000 00000 28480 00000 28480 00000 Factory Selected Component Refer to Section 5 Replaceable Parts Mfr Part Number 08904 00010 08904 61012 08904 61016 AD42AH 42 AD42AH AD42AH 554808 1 554808 1 1906 00 00 2580 1906 00 00 2580 0361 1259 0361 1259 ORDER BY DESCRIPTION 1510 0038 2190 0068 ORDER BY DESCRIPTION 2190 0068 6960 0132 6960 0132 6960 0132 6960 0132 2190 0027
22. 28480 28480 28480 28480 28480 28480 Factory Selected Component Refer to Section 5 Model 8904A Mfr Part Number 08904 61004 08904 61006 08904 61008 08904 61008 5061 4837 5061 4837 08904 61015 08904 61015 08904 61007 08904 61007 08904 61007 08904 61007 A Errata part change rev 01 NOV89 Model 8904A Reference HP Part Qty Designation Number D 1 08904 00010 7 2712 to 2942 2 08904 61012 7 2948A and above 2 08904 61014 1 3 0361 1020 2 4 0361 1020 2 5 0361 1020 2 0361 1020 2 7 1252 2245 5 8 1252 2245 5 9 2190 0007 2 10 2190 0007 2 11 0361 1259 9 12 0361 1259 9 13 0590 1251 14 1510 0038 8 15 2190 0068 5 16 0590 1251 6 17 2190 0068 5 18 6960 0132 1 19 6960 0132 1 20 6960 0132 1 21 6960 0132 1 22 2190 0027 23 2950 0006 3 24 1251 7788 9 25 1251 7788 9 26 2190 0584 27 2190 0584 0 28 2190 0068 6 29 30 2190 0068 6 314 32 0590 1251 6 33 2190 0068 6 34 0590 1251 6 35 2190 0068 6 Refer to Section 7 for update information rev 01JUL9I1 Table 6 3 Replaceable Parts Description REAR PANEL SILKSCREEN LABEL DECK ASSY DECK ASSY RIVET BLIND PL STEM DOME HD 12501 RIVET BLIND PL STEM DOME HD 12501 RIVET BLIND PL STEM DOME HD 125DIA RIVET BLIND PL STEM DOME HD 125DIA SCREW LOCK KIT AMP CHAMP CONN SCREW LOCK KIT AMP CHAMP CONN WASHER LK INTL T NO 6 141 IN ID WASHER LK INTL T NO 6 1414INID RIVET BLIND DR PIN DOME HD
23. 2942A and above order a 2 8V battery HP 1420 0338 Procedure 1 Switch LINE to OFF and disconnect the power cord 2 Remove the instrument s top cover The cover may be tightly secured in the groove of the bottom cover If the top cover does not pull off easily after backing out the screw on the rear edge back out the screw on the rear edge of the bottom cover also rev 15DEC89 Troubleshooting Memory Backup Battery 8 48 1 Service Model 8904A 3 Partially remove the A2 Digital Assembly as follows figure 6 1 Main Deck Assembly Top may be helpful a Unplug all connectors on the A2 assembly except the two soldered in coaxial cables To remove the front most keyboard ribbon cable lift up on its retainer and push the retainer forward b Remove the single Torx screw securing the A2 assembly c Carefully lift the A2 assembly from the seven plastic holding posts by compressing the small holding tangs with needle nose pliers and pulling the board up until the printed circuit board is free from the posts Carefully rotate the board upward hinging it from the left side as you face the front panel until it is vertical This should allow access to both sides of the assembly 5 2 co BATTERY BACKUP TO EXTERNAL POWER SUPPLY S5V F2 5583 3303 8 5524 102 WRITE gt 1EN3 READ Figure 8 12 1 Partial Schematic of 2 Digital Assembly Showing the Battery Backup 4 Refer to Figure
24. 4535 0160 4789 0160 4832 0160 4832 0160 4832 0160 3563 0160 4835 0160 4835 0160 4535 0160 0572 0160 0573 0160 4040 5024E0200RD689D 0160 4535 0160 4535 0160 4832 0160 4832 0160 4791 0160 4795 0160 4835 Factory Selected Component Refer to Section 5 6 7 Replaceable Parts Model 8904A Table 6 3 Replaceable Parts Reference HP Part infi Mfr Designation Number D Qty Description Coda Mfr Part Number A3C403 0160 4835 7 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4835 404 0160 4835 7 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4835 A3C405 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 406 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 A3C407 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 408 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 409 0160 4547 8 2 CAPACITOR FXD 150PF 5 200VDC CER 28480 0160 4547 410 0160 4526 3 2 CAPACITOR FXD 42PF 5 200VDC CER 0 30 28480 0160 4526 411 0160 4493 3 1 CAPACITOR FXD 27PF 5 200VDC CER 0 30 28480 0160 4493 412 0160 4526 3 CAPACITOR FXD 42PF 5 200VDC CER 0 30 28480 0160 4526 413 0160 4547 8 CAPACITOR FXD 150PF 5 200VDC CER 28480 0160 4547 A3C414 420 NOT ASSIGNED 421 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 150D685X9035B2 A3C422 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 1500685 903582 423 0180 01
25. 65 eec DEC 68 052 087 4 9 24 92 1 PL teu 81 w 155 100 H314I7dWY eu 822 55 ZED BEZ9 165 dggzc 4058 BEI 822 nao p gsz 91 7641405 SMOINV171395 IN 01 Service Model 8904 A3 Component Coordinates 1 of 2 come xy A3 Component Coordinates 2 of 2 im R18 Cue o 0296 0284 c213 ete RO cs p 2 2222 4 Qe NOTES Jf THE VOLTAGES SHOWN AT THE OUTPUTS OF 10 K2 K4 AND K6 ARE WITH THE RELAY CONTACTS CLOSED THE OUTPUT OF THE FLOATING AMPLIFIER DRIVER AND ON OFF SWITCH WITH 401 OPEN INITIAL INSTRUMENT SETTINGS VOLTAGES ON THIS SCHEMATIC UNLESS OTHERWISE NOTED SHOULD BE MEASURED AFTER KEYING IN FOR A3 FOR A18 En 8 80 SHIFT PRESET SHIFT PRESET SHIFT FLOAT 1 OFF SHIFT FLOAT 2 OFF 1 CHANNEL CONFIG 1 CHANNEL CONFIG NEXT NEXT NEXT AMPTD 18 V 18 Figure 8 15 Service Sheet Information Component Locator P O 10 OUTPUT ASSEMBLY 552 SEE REVERSE SIDE 8 54 Model 8904 Service CHANGES All serial prefixes On the A3 schematic R417 R422 Under FLOATING DRIVER AND ON OFF SWITCH change the value of R417 and R422 to 75K ohms 553 89 8 54 1 E NOFF 91 28 6 12
26. A2 POWER SUPPLIES J1 1 415312 1034 DIGITAL DATA INPUT CLOCK POWER SUPPLY CONDITIONERS 16 WDC 16voc r 27 inr FILTERED 582 41 29 16 3V0C 41 393 e GND ACHIEVED THRU MOUNTING POST int FILTERED TRACK AND HOLD CIRCUIT DRIVE SAMPLER SWITCH SAMPLER AMPLIFIER 15 0 DIGITAL TO ANALOG CONVERTER 15V0C 5VDC 66 8 810 CLOCK 5 g Fy 5VDC gt 5 0 14 NC 4 9 C216 15 0 2 giv 318 80 30 02 Ydo R224 R217 17 TURN D DAC 51 1K 6 8 8 810 4201132 CW LEVEL 15VDC SMC TEST 928141 4281 2 POINT ON aa PC BOARD R221 R226 R225 3 16K 3 16K eet 12 0 1 CURRENT SOURCE 16VDC CF n 551 8 51 Service 8904 Component Coordinates 1 of 2 A3 Component Coordinates 2 of 2 Tei 2 5 gt uzes 201 5 5 pr Timo grau 24 o m uel ui esas 0381 y ont we 6494 sV N NOTES INITIAL INSTRUMENT SETTINGS esis Raza VOLTAGES ON THIS SCHEMATIC UNLESS OTHERWISE NOTED SHOULD BE MEASURED
27. AFTER KEYING IN 3 FOR A3 FOR A19 SHIFT PRESET SHIFT PRESET SHIFT FLOAT 1 OFF SHIFT FLOAT 2 OFF 1 CHANNEL CONFIG fi CHANNEL CONFIG gt NEXT NEXT NEXT 18 V 18 5 TPs TP482 Figure 8 14 Service Sheet Information Com ponent Locator P O 10 OUTPUT ASSEMBLY SS 1 SEE REVERSE 5106 8 52 Model 8904A Service CHANGES All serial prefixes On the A3 schematic e C230 Under SHARP CUTOFF ELLIPTIC change the value of C230 to 552 rev 23MAR89 8 52 1 S 8 255 ess Cea 0 8 3 00491 432090A491 3290 91 98 1 8 52 HOT 98 CHED 89 593 gt 20 SN ad di 910 meal ys 942 nta ae 42 8 2 L S CA429g0A9T 4200A9T 4 90A9 1 tdl 10 A18 9 ni e 254 2 3 194 C4 D0A9 4 90A91 led 2 242 86 ssu TY JOAST 3 90491 6 8 IdWv ddA 193138 3114 14 1037135 434714 14 3 05 193138 31714 14 193138 831113 14 831113 5 831113 L3IHS THM 081 034 881 034 M03 59 11135 5 YILINI OL 5 0 1100 NO 035070 ATIVWHON z T p p5 Lou VII E gt LN O d 9QAS NO N3d0 A TT1VMHWON A33M4AS 334 6 T ct 814 0 4 20
28. Changes Model 8904 19 2 1 E lt gt LT Figure 7 6 Front Panel Assembly 2923A and above 7 18 Firmware Updates Hardware Modifications 15DEC89 HP8904A Table of Contents TABLE OF CONTENTS Section 8 Service Introduction To This 8 1 How The Section Is Organized 8 1 Safety Considerations ose e aren de ae 8 1 Service Tools Helps and Information 8 1 Schematic Symbology and Schematic Diagram Notes 8 3 Principles of Operation 8 15 Overall iue p ge eie RR m amp Hohe 8 15 A2 Digital Assembly ua og ee ee ee de rg 8 23 A9 Output Assembly Barge EA Ghar 4S 8 24 Troubleshooting 8 29 Generali cards ep ce ox Or E ch as sas ok eee a ee Be 8 29 Digital Assembly or 10 Output Assembly Interface 8 30 A2 Digital Assembly 1 Keyboard Assembly 8 38 Digital Assembly 5 Display Assembly Interface 8 41 AS or Output Assembly RU e SW BA 8 42 Phase Synchron
29. Drive The Sampler Drive must provide sufficient current through transformer T1 to turn on hard the sampler diodes U201A B C and F in the Sampler Switch When the sampler diodes are on the voltage at the DAC output transfers to capacitor C219 at the input of the Sampler Amplifier Operation of the Sampler Drive is most easily seen by referring to the simplified schematic of Figure 8 9 Principles of Operation A3 Model 8904A Service TO SAMPLE SWITCH C222 FROM CLOCK SYNC HIGH TRUE FROM CLOCK SYNC 02 Figure 8 9 Simplified Diagram of the Sampler Drive Differential input transistors Q205 and Q206 are driven in complement by the outputs of D flip flop U2A the Clock Sync flip flop The emitter current for Q205 and Q206 is supplied by a common 10 mA current source The current source is Q207 and associated parts in the main schematic diagram Diode CR207 thermally tracks the base emitter junction of Q207 to thermally compensate the current source The current from the current source alternates between Q205 and Q206 each half clock period Diodes CR202 and CR203 clamp the collectors of Q205 and Q206 to approximately 6V CR204 and CR205 clamp the collectors to 10V Q204 and Q202 are emitter followers which drive one side of transformer T1 0203 and 9201 similarly drive the opposite side of T1 but are 180 out of phase Capacitor C201 forces the junction of R201 and R202 to follow the bases and emi
30. FOR OPTION 005 CABLE TIE 062D 09W ADDED FOR OPTION 005 CABLE TIE 062D 09W ADDED FOR OPTION 005 LABEL FOR OPTION 005 NOT ASSIGNED NOT SEPARATELY REPLACEABLE CABLE TIE 062D 09W ADDED FOR OPTION 006 BOARD PULLER Mfr Code 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 Factory Selected Component Refer to Section 5 Model 8904A Mfr Part Number 08904 00022 0515 0954 0515 0954 0515 1234 ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION 08904 80015 ORDER BY DESCRIPTION ORDER BY DESCRIPTION 0515 1860 0515 1860 0515 1860 0515 1860 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 08904 80017 1400 0249 08904 00012 Errata part change rev 01NOV89 690 9 68AONITOQ 024 NY YOY jaung PUOL 40 2 295 166 03 VZILZ 401 Kjquiassy yoaq 1 9 aansig Ae uM x 1130 T a 0 d ONILNDOH HOLIMS x W PP AY a 54315 1801557 INOHJ ON Jn23S 34804338 OLN A J8H3SSV 13NVd 1 A1843S5SV 14 4 OL HOLIIMS syed 7068 TOPON Replaceable Parts Model 8904A 142 TO Wt SWITCH THEN ITEM 89 LEAVIN 2 lt 2 5 Ri DETAIL A SWITCH MOUNTING Figure 6 1 Main Dec
31. MLD 1UH 5 NOT ASSIGNED INDUCTOR RF CH MLD 5 6UH 5 INDUCTOR RF CH MLD 18UH 5 166DX 385LG INDUCTOR RF CH MLD 820NH 5 HEAT SINK SGL TO 5 TO 39 CS HEAT SINK SGL TO 5 TO 39 CS HEAT SINK SGL TO 5 TO 39 CS HEAT SINK SGL TO 5 TO 39 CS INSULATOR XSTR POLYI Mfr Code 9 171 9 171 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 88330 88330 28480 88330 88330 88330 15636 15636 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 Factory Selected Component Refer to Section 5 Model 8904A Mfr Part Number 1N4150 1N4150 1251 8601 1251 4670 1258 0141 1250 0835 1250 0835 1250 0835 1251 4670 1258 0141 1251 4670 1258 0141 1251 4670 1258 0141 1250 0836 1250 0836 R9131 1 R9131 1 R9131 1 R9131 1 R9131 1 R9131 1 0490 1190 R9131 1 R9131 1 R9131 1 R8777 1 R8777 1 9100 3560 9100 3548 9100 3548 9100 1675 9100 1675 9100 1640 08904 80001 08904 80005 08904 80002 9100 1663 08904 80003 9100 3551 9100 3560 9140 0454 9100 3315 1205 0213 1205 0213 1205 0213 1205 0213 0340 0834 A Errata part change rev 01NOV89 Model 8904A Replaceable Parts Table 6 3 Replaceable Parts Reference HP Part Mfr Designation Number D Qty Description Code Mfr Part Number 0340 0834 0 INSULATOR
32. ORDER BY DESCRIPTION 2058 18 2 2058 18 2 2190 0584 2190 0584 ORDER BY DESCRIPTION ORDER BY DESCRIPTION 0590 1251 ORDER BY DESCRIPTION 0590 1251 ORDER BY DESCRIPTION 4 Errata part change 6 19 Replaceable Parts Reference HP Part Qty Designation Number D 2712A to 2917A 36 T 371 381 1 2923A above 36 08904 61021 8 1 37 38 08904 40006 5 1 39 08904 00021 0 1 40 0515 1851 4 21 41 0515 1851 4 42 0515 1851 4 43 0515 1851 4 44 0515 1851 4 45 0515 1851 4 46 0515 1851 4 2712A to 2917A 47 0515 1851 4 2923A and above 47 48 0515 1851 4 49 0515 1851 4 2712A to 2917A sot 0515 1851 4 2923A and above 50 51 0515 1851 4 52 0515 1851 4 53 0590 1251 6 53 2950 0035 8 54 0590 1251 6 54 2950 0035 8 55 6960 0132 1 tRefer to Section 7 for update information 6 20 Table 6 3 Replaceable Parts Description SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT PANEL FRONT AY NOT SEPARARETLY REPLACEABLE KEYPAD PUNCHED SHIELD DISPLAY SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SEE SECTION 7 FOR FRONT PANEL RET
33. Output Assembly Option 002 present move the A10 assembly out of the way by following the procedure of Figure 8 11 How to Access A3 in Instruments Equipped with Option 002 2 To troubleshoot the Output Assembly a Turn to the schematic diagram Service Sheets 1 through 4 of the circuit that is suspect b Set the instrument as instructed in the boxed text entitled INITIAL INSTRUMENT SETTINGS c Connect the oscilloscope to the point to be tested d Alter the instrument settings if instructed by the troubleshooting text for that testpoint and make the measurement 8 42 Troubleshooting or 10 Assembly Model 8904 Service PHASE SYNCHRONIZATION OPTION 005 Description The operation of the unit to unit phase synchronization circuits Option 005 and serial prefix beginning 2948A only is checked by monitoring the signals on the rear panel clock synchronization and phase reset input and output lines The checks should pinpoint the failure to either the A2 Digital Assembly or an interconnecting cable Marginal failures may be able to be corrected by performing the Phase Synchronization Adjustment in Section 5 however this is recommended only when there is strong reason to suspect that the failure is due to slight timing errors Performance of the phase synchronization circuits can be verified by running the Unit to Unit Phase Accuracy Performance Test in Section 4 Equipment Digital Multimeters 5
34. Output will be active when one and only one input is active m and only m Output will be active when m and only m inputs are active replace m with a number Logic Identity Output will be active only when all or of the inputs are active when all inputs are identical output will be active Amplifier The output will be active only when the input is active can be used with polarity or logic indicator at input or output to signify inversion Signal Level Converter Input level s are different than output level s Bilateral Switch Binary controlled switch which acts as an on off switch to analog or binary signals flowing in both directions Dependency notation should be used to indicate affecting affected inputs and outputs Note amplifier symbol with depen dency notation should be read to indicate unilateral switching X Y Coder Input code X is converted to output code Y per weighted values or a table Functional Labels The following labels are to be used as necessary to ensure rapid identification of device function MUX Multiplexer The output is dependent only on the selected input DEMUX Demultiplexer Only the selected output is a function of the input CPU Central Processing Unit 8 8 Model 8904A Functional Labels mCNTR Table 8 1 Schematic Diagram Notes 6 of 11 DIGITAL SYMBOLOGY REFERENCE INFORMATION Sequential Logic Functions Monostable Single
35. XSTR POLYI 28480 0340 0834 A3MP7 0340 0834 0 INSULATOR XSTR POLYI 28480 0340 0834 ASMP8 0340 0834 0 INSULATOR XSTR 28480 0340 0834 1 1854 0477 7 1 TRANSISTOR NPN 2N2222A SI TO 18 SOOMW 04713 2N2222A A3Q2 1853 0281 9 1 TRANSISTOR PNP 2 2907 SI TO 18 PD 400MW 04713 2N2907A A3Q3 13 NOT ASSIGNED A3Q14 1854 0809 9 1 TRANSISTOR NPN 2N2369A 1 TO 18 PD 360MW 28480 1854 0809 A3Q15 1853 0405 9 2 TRANSISTOR PNP SI PD 300MW FT 850MHZ 04713 2N4209 A3Q16 1853 0659 5 8 TRANSISTOR PNP SI PD 625MW FT 200MHZ 28480 1853 0659 A3017 1854 1177 12 TRANSISTOR NPN 1 PD 625MW FT 200MHZ 28480 1854 1177 A3Q18 1854 1177 6 TRANSISTOR NPN 1 625MW FT 200MHZ 28480 1854 1177 19 1853 0659 5 TRANSISTOR PNP SI 625MW 200 2 28480 1853 0659 A3Q20 1853 0405 9 TRANSISTOR PNP SI PD 300MW FT 850MHZ 04713 2N4209 212 1854 1177 6 TRANSISTOR NPN S 625MW FT 200MHZ 28480 1854 1177 A3Q22 32 1854 1177 TRANSISTOR NPN 1 PD 625MW FT 200MHZ 28480 1854 1177 A3034 200 A30201 1854 1177 TRANSISTOR NPN SI PD 625MW FT 200 2 28480 1854 1177 AaQ202 1854 1177 6 TRANSISTOR NPN SI PD 625MW FT 200MHZ 28480 1854 1177 1853 0659 5 TRANSISTOR SI PD 625MW 200MHZ 28480 1853 0659 30204 1853 0659 5 TRANSISTOR SI 625MW FT 200MHZ 28480 1853 0659 2052 1854 1177 TRANSISTOR NPN SI 625MW FT lt 200MHZ 28480 1854 1177 AaQ206 1854 1
36. for off page connection In the example signal flow is continued on Service Sheet 12 at the point marked Number only on page connection 8 5 Service 8 6 Model 8904A Table 8 1 Schematic Diagram Notes of 11 Indicates multiple paths represented by only one line Letters or names identify indi vidual paths Numbers indicate number of paths represented by the line Coaxial or shielded cable Ferrite bead Increases the self inductance of the conductor passing through the bead Relay Contact moves in direction of arrow when energized Indicates a pushbutton switch with a momentary ON position Feedthrough capacitor Acts as a feedthrough terminal when mounted on a chassis or a frame Indicates a PIN diode Indicates a current regulation diode indicates a voltage regulation diode indicates a capacitive varactor diode Indicates a Schottky hot carrier diode Light emitting diode Muttiple transistors in a single package physical location of the pins is shown in package outline on schematic Identification of logic families as shown in this case ECL Model 8904A Service Table 8 1 Schematic Diagram Notes 4 of 11 DIGITAL SYMBOLOGY REFERENCE INFORMATION Input and Output Indicators Implied Indicator Absence of polarity indicator see below implies that the active state is a relative high voltage level Absence of negation indicator see below im plies
37. ground wire ever sustains heavy current long enough the solder on the connections can erode weaken and eventually cause the connections to loosen Should ground contact break the chassis can no longer be guaranteed to be at ground potential 2 With ground contact interrupted the chassis could become hot if the neutral or high lines of the power cord come in contact with the chassis through some other fault The chassis then becomes a shock hazard With proper wrapping and soldering of the ground connections the ground wire will maintain a reasonable mechanical connection even though the solder has deteriorated This information explains how to check for the possible shock hazard and how to correct it The check for the shock hazard is by simple visual inspection Corrective action if needed consists of replacing the ground wire with attention paid to wrapping and soldering it to its solder lugs Replacement of the wire should be made by someone with wire soldering skills The following parts may be required Solder Lug 0360 0036 Cable Tie 1400 0249 Wire Green Yellow 8150 2919 7 10 Firmware Updates Hardware Modifications rev 15DEC89 Model 8904A Instrument Changes Checking for the Shock Hazard 1 2 rev 15DEC89 Unplug the power cord from its rear panel socket Remove the instrument s top cover by backing out the screw in the center of the rear edge of the cover This is a captive screw and wil
38. on the rear panel the instrument already has its serial suffix correctly entered 3 Key in SHIFT SPECIAL 8 7 ENTER SHIFT END The display should read Serial Number Installation Enter 5 digit serial number S N NOTE The SPECIAL key is labeled in blue above the LAST key The END key is labeled in blue above the ENTER key After keying in SHIFT SPECIAL the display should be f1 Special 0 f2 Status Off f4 Exit Last state recalled on power up After keying in 8 7 the display should be 1 Special 87 12 Status Off f4 Exit O Last state recalled on power up After heying in ENTER the instrument will beep After keying in SHIFT END if the display is as follows the instrument serial number cannot be entered The A2 Digital Assembly must be replaced Serial Number Installation Serial number cannot be installed Troubleshooting Serial Numbers Model 8904A Service 4 Key in the serial suffix which is printed on the rear panel serial label then press ENTER For example if the serial number on the label is 1234456789 key in 5 6 7 8 9 then press ENTER The display should now read Press SHIFT 22 to install S N 56789 If S N is wrong use Reenter 4 Exit The serial suffix that you keyed in should appear at the end of the top line In the example shown it is 56789 NOTE If a typing error occurs as the serial suffix is being ent
39. operating position Re insert the power cord and switch LINE 10 11 15DEC89 to ON Press SHIFT PRESET The display should show the correct instrument serial number suffix for a few seconds Re install the instrument s top cover Troubleshooting Memory Backup Battery 8 48 3 7878 dnxoeg Lowa Surjoouse qno1 680A AST 024 puo Var6c xya4qd 101425 amp 42370g ay Kqquiassy 40 1070207 2721 98 9 lo o o o ooooooou 8 9900000000 15 1 000000000 U4 pw 000500590 949 0101 REF IN 3101 J102 REF OUT 0163 0000000 00000000 e 6006000 u22 u20 0000000 00000000 043 01010000000 0000009 O 0990000 9193 00430 oao 0000000 8000000 Sooo WY 019 J2 oo 0000000000 o U46 339 99000000000 044 0000000000 o A 99000009000 000000000 00900000000 8 0000000000 oo 0000000000 00050000900 4 93 6000000000 O 00000000
40. operational amplifier peak used in parts pulse amplitude modulation printed circuit pulse code modula tion pulse count modulation pulse duration modulation picofarad phosphor bronze Phillips positive intrinsic negative peak inverse voltage peak phase lock phase lock oscillator phase modulation positive negative positive polystyrene porcelain positive position s used in parts list position potentiometer peak to peak peak to peak used in parts fist pulse position modulation preamplifier pulse repetition frequency pulse repetition rate picosecond point pulse time modulation pulse width modulation rectifier reference regulated replaceable radio frequency radio frequency interference round head right hand resistance inductance capacitance rack mount only root mean square read only memory rack and panel reverse working voltage scattering parameter second time second plane angle slow blow fuse used in parts list silicon controlled rectifier screw Selenium SEMICON semiconductor SHF superhigh frequency 2 Signal to noise ratio singie pole doubie throw split ring single pole single throw Service Sheet single sideband stainless steel Standing wave ratio synchronize timed slow biow fuse temperature compensating Model 8904A transistor transistor transistor television television int
41. post does not extend through shield Lift A10 from instrument and carefully lay A10 aside coax cables will still be connected Replace hold down screw from step 3 with spacer found under A10 into mounting hole in center of This screw must be in place during adjustment procedure for A3 Figure 8 11 How to Access A3 in Instruments Equipped with Option 002 Troubleshooting Digital Output Interface Service 8 31 Service Model 8904A Il sia SE FEO ESI Nu ge 16 3 Vde to J1 Pin 28 16 3 Vde to J1 Pin 31 Serial Prefix dd E i 2948A and m E 1 above only 2 Not Opt 006 5 1Vd to Ji in 16 2 Ji Pins 29 and 30 16 3 to 41 Pins 26 and 27 Figure 8 12 Power Supply Testpoints on A3 or A10 8 32 Troubleshooting Digital Output Interface rev 1560 89 Model 8904A Service 3b Clock Checks Using a Counter a If the counter has an external 10 MHz timebase reference input connect it to the rear panel 10 MHz REF OUT of the Multifunction Synthesizer NOTE If the counter does not have an external reference the readings in the following steps may be off several counts This does not indicate a failure b Connect the high impedance counter input to pin 3 of U2 The cou
42. screw on the rear edge of the bottom cover also 3 For instruments with serial prefix 2942A and below locate U12 and U13 on the A2 assembly front horizontal board For instruments with serial prefix 2948A and above locate only U12 They are in sockets The reference designator is labeled beside the IC 4 Pry out the old ROM or ROMs with a blade type screwdriver 5 Plug in the new ROM or ROMs in the correct sockets and with the correct pin orientation 6 Check the operation of the instrument Serial Prefix 2740A and below The recommended replacement for A2U12 is HP Part 08904 87010 The recommended replacement for A2U13 is HP Part 08904 87008 If either A2U12 or A2U18 fails replace the other part also if its part number differs Serial Prefix 2742A and above The recommended replacement for A2U12 is HP Part 08904 87011 The recommended replacement for A2U13 is HP Part 08904 87009 rev 01JUL91 Firmware Updates Hardware Modifications 7 9 Instrument Changes 8904A 7 7 MODIFICATION FOR POSSIBLE GROUND WIRE SHOCK HAZARD Serial Prefix 2737A and below On some instruments with serial prefix 2737A and below the grounding wire from the rear panel line socket to the metal chassis may not have been wrapped and soldered in compliance with strict safety standards This condition does not create a safety hazard under normal use however a safety hazard can develop if the following two conditions occur 1 If the
43. shot multivibrator Output becomes active when the input be comes active Output remains active even if the input becomes inactive for a period of time that is characteristic of the device and or circuit Oscillator The output is a uniform repetitive signal which alternates between the high and low state values If an input is shown then the output will be active if an only if the input is in the active state Flip Flop Binary element with two stable states set and reset When the flip flop is set its outputs will be in their active states When the flip flop is reset its outputs will be in their inactive states Toggle Input When active causes the flip flop to change states Set Input When active causes the flip flop to set Reset Input When active causes the flip flop to reset J Input Analogous to set input K Input Analogous to reset input Data Input Always enabled by another input generally input see Dependency Notation When the D input is dependency enabled a high level at D will set the flip flop a low level will reset the flip flop Note strictly speaking D inputs have no active or inactive states they are just enabled or disabled Count Up Input When active increments the contents count of a counter by m counts m is replaced with a number Count Down Input When active decrements the contents count of a counter by m counts m is replaced with a number Shift Right Do
44. that the active state is a relative high voltage level at the input or output Polarity Indicator The active state is a relatively low voltage level Dynamic Indicator The active state is a transition from a relative low to a relative high voltage level inhibit Input input that when active inhibits blocks the active state outputs of a digital device Analog Input Input that is a continuous signal function e g a sine wave Polarity Indicator used with Inhibit Indicator indicates that the relatively low level signal inhibits blocks the active state outputs of a digital device Output Delay Binary output changes state only after the referenced input m re turns to its inactive state m should be replaced by appropriate dependency or func tion symbols Open Collector Output Open Emitter Output Three state Output Indicates outputs can have a high impedance disconnect state in addition to the normal binary logic states 8 7 Service Model 8904 Table 8 1 Schematic Diagram Notes 5 of 11 DIGITAL SYMBOLOGY REFERENCE INFORMATION Combinational Logic Symbols and Functions Summing Junction Outputs added together at a common point AND All inputs must be active for the output to be active OR One or more inputs being active will cause the output to be active Logic Threshold m or more inputs being active will cause the output to be active replace m with a number EXCLUSIVE OR
45. 090 01 193 a OUTPUT 19 00000000 90000000 2 06000000 00000000 9113 525970 O oooooooo o ORO ognja 61 OREO pe JEJ 00000 oka pmo 15 E 33 1 76 ORB 00600065000 U38 020900000000 9000000 gooo oooooo 0050006 035 acado ogo 0105 193 b OEBO 19 o 0900000 pelo 5 6000000d0000000fo00o0o u27 0000 38 440 0060000000 Dopooooooo queso a RE a a a 3 E AH3 L1V8 HOLIOVdVO AlddNs H3MOd WNYSLX3 991195 7068 Model 8904 Service cl edie See al an I1 ig EAS IE To External Power Supply Capacitor CS Battery Figure 8 12 3 Component Locator for A2 Digital Assembly Detailing the Battery Backup Serial Prefix 2948A and Above
46. 0957 1902 0957 1902 0944 1902 1397 1902 1397 TRefer to Section 7 for update information a a Qty Table 6 3 Replaceable Parts Description D A 12 1 2 BIT 24 DIP C BPLR NOT ASSIGNED TRANSISTOR ARRAY 16 PIN PLSTC DIP OP AMP PRCN 8 DIP C PKG TRANSISTOR ARRAY 16 PIN PLSTC DIP DELAY LINE ACTIVE DELAY LINE TTL DIODE ARRAY 25MA VF DIFF 5MV INSTM AMPL CUR 10 PKG OP AMP LOW BIAS H IMPD 8 DIP C PKG OP AMP HS 8 DIP C PKG OP AMP HS 8 PKG OP AMP HS 8 DIP C PKG INSTM AMPL CUR 10 DIP P PKG NOT ASSIGNED COMPARATOR GP QUAD 14 DIP C PKG NOT ASSIGNED DIODE ZNR 24V 5 DO 35 PD 4W TC 094 NOT ASSIGNED DIODE ZNR 15V 5 DO 35 PD 4W TC 087 NOT ASSIGNED DIODE ZNR 9 1V 5 DO 35 PD 4W TC 069 NOT ASSIGNED DIODE ZNR 9 1V 5 00 35 PD 4W TC 069 NOT ASSIGNED DIODE ZNR 2 7V 5 DO 35 PD 4W 044 NOT ASSIGNED VOLTAGE SUPPRESSOR VR 10 2V BV 11 4V MIN VOLTAGE SUPPRESSOR VR 10 2V BV 11 4V MIN Mfr Code 24355 13606 06665 13606 07393 28480 27014 27014 27014 27014 27014 27014 04713 28480 28480 28480 28480 28480 04713 04713 8904 Mfr Part Number ADS565AJD ULN 2003A OP 27GZ ULN 2003A TTLDL 60 SELECTED 1901 1011 LHOO02CN LF356BJ LM6361J SELECTED LM6361J SELECTED LM6361J SELECTED LHOO02CN LM339J 1902 0967 1902 0962 1902 0957 1902 0957 1902 0944 1N6273A 1N627
47. 0MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE HV RECT 600V 1A DIODE HV RECT 600V 1A DIODE HV RECT 600V 1A DIODE HV RECT 600V 1A NOT ASSIGNED DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE GEN PRP 125MA DO 35 DIODE GEN PRP 125MA DO 35 DIODE GEN PRP 125MA DO 35 DIODE GEN PRP 125MA DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200 2NS 00 35 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE CUR RGLTR 1N5312 100V DO 7 DIODE CUR RGLTR 1N5312 100V DO 7 DIODE CUR RGLTR 1N5312 100V DO 7 DIODE CUR RGLTR 1N5312 100V DO 7 DIODE SWITCHING 80V 200MA 2NS DO 35 DIODE SWITCHING 80V 200MA 2NS DO 35 Mfr Code 9N171 9N171 28480 28480 28480 28480 28480 28480 9N171 9N171 9N171 04713 28480 9N171 9N171 9N171 9N171 9N171 9N171 28480 28480 28480 28480 9N171 9N171 9N171 9N171 28480 28480 28480 28480 9N171 9N171 9N171 9N171 04713 04713 04713 04713 9N171 9 171 Replaceable Parts Mfr Part Number 1N4150 1N4150 1901 0028 1901 0028 1901 0518 1901 0518 1901 0518 1901 0518 1N4150 1N4150 1N4150 1 5312 1901 0518 1 4150 1 4150 1 4150 1 4150 1 4150 1 4150 1901 0873 1901 0873 1901 0873 1901 0873 1 4150 1 4150 1 4150 1 4150 1901 0880 1901 0880 1901 08
48. 1 If the wrap on either end of the ground wire is not within specification the ground wire must be replaced Remove the screw holding the ground wire to the instrument standoff Use a T10 or T15 Torx screwdriver as needed Cut the gray cable tie which secures the main wire harness to the standoff with a pair of diagonal wire cutters Avoid cutting into the insulating sheath of the harness With the main harness free move it up and to the left so as not to interfere with soldering Heat the soldering iron You will also need a roll of solder wick On the line cord socket heat the solder on the lug where the ground wire is attached and apply the solder wick At the same time move the ground wire around and pull the ground wire out of the lug Avoid touching any of the loose wires with the soldering iron Cut an 8 cm 3 2 inch length of new 18 gauge ground wire HP 8150 2919 Strip 8 mm 5 16 inch of insulation from each end of the wire Wrap and solder one end of the stripped ground wire onto a new solder lug HP 0360 0036 Refer to figure 7 5 for wrapping details Insert the other end of the new ground wire into the empty lug on the line cord socket After the wire is properly wrapped solder it in place 7 12 Firmware Updates Hardware Modifications rev 15DEC89 Model 8904A 10 11 12 Instrument Changes NOTE It is possible that the 22 gauge black wire may break while replacing th
49. 142 1434 1445 145 2912 to 2942 146 148 2948 and above 146 147 148 149 2912A to 2942A 150 166 2948A and above 150 151 152 153 154 155 156 157 158 159 160 HP Part Number 08904 00022 0515 2028 0515 0954 0515 1234 3050 0891 3050 0891 3050 0891 08904 80015 0515 1851 0515 1851 0515 1860 0515 1860 0515 1860 0515 1860 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 08904 80017 1400 0249 08904 00012 D o Qty tRefer to Section 7 for update information 6 22 2 Table 6 3 Replaceable Parts Description NOT ASSIGNED NOT ASSIGNED NOT SEPARATELY REPLACEABLE NOT SEPARATELY REPLACEABLE NOT ASSIGNED LINE SWITCH BRACKET SCREW MACH 2 5 X 0 45 4MM LG SCREW MACH 2 5 X 0 45 4MM LG SCREW MACH 3 5 0 6 8MM LG NOT ASSIGNED WASHER FL MTLC 3 0MM 3 3MM ID WASHER FL MTLC 3 0MM 3 3MM ID WASHER FL MTLC 3 0MM 3 3MM ID NOT ASSIGNED NOT ASSIGNED LABEL FOR OPTION 006 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 006 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 006 SCREW MACHINE ASSEMBLY M3 5 X 0 6 ADDED FOR OPTION 006 SCREW MACHINE ASSEMBLY M3 5 X 0 6 ADDED FOR OPTION 006 SCREW MACHINE ASSEMBLY M3 5 X 0 6 ADDED FOR OPTION 006 SCREW MACHINE ASSEMBLY M3 5 X 0 6 ADDED FOR OPTION 006 CABLE TIE 062D 09W ADDED FOR OPTION 005 CABLE TIE 062D 09W ADDED FOR OPTION 005 CABLE TIE 062D 09W ADDED
50. 16 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 1500685 903582 424 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC 56289 150D685X9035B2 425 0121 0451 3 1 CAPACITOR V TRMR AIR 1 7 11 175V 74970 187 0106 028 426 0160 4789 0 CAPACITOR FXD 15 5 100VDC CER 04 30 28480 0160 4789 A3C425 430 NOT ASSIGNED A3C431 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 A3C432 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 1500685 903582 A3C433 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 434 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 150D685X9035B2 435 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 436 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 1500685 903582 A3C437 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 A3C438 0180 0116 1 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 150D685X9035B2 A3C439 NOT ASSIGNED 440 0160 4801 7 7 CAPACITOR FXD 100 5 100VDC CER 28480 0160 4801 441 0160 4801 7 CAPACITOR FXD 100PF 5 100VDC CER 28480 0160 4801 442 0160 4795 8 CAPACITOR FXD 4 7PF 5 100VDC CER 28480 0160 4795 A3C443 0160 4795 8 CAPACITOR FXD 4 7PF 5PF 100VDC CER 28480 0160 4795 444 0160 4801 7 CAPACITOR FXD 100 5 100VDC CER 28480 0160 4801 A3C445 0160 4801 7 CAPACITOR FXD 100PF 5 100VDC CER 28480 0160 4801 446 0160 4801 7 CAPACITOR FXD 100PF 5 100VDC CER 28480 0160 4801 447 01
51. 177 6 TRANSISTOR NPN SI PD 625MW FT 200MHZ 28480 1854 1177 A30207 1854 1177 TRANSISTOR NPN SI PD 625MW FT 200MHZ 28480 1854 1177 208 1853 0659 5 TRANSISTOR PNP SI PD 625MW 200 2 28480 1853 0659 A3Q209 1855 0276 6 2 TRANSISTOR J FET 2N4416A N CHAN D MODE 04713 2 416 A3Q210 1855 0276 6 TRANSISTOR J FET 2N4416A N CHAN D MODE 04713 2N4416A A3Q300 1853 0659 5 TRANSISTOR PNP 51 625MW FT 200MHZ 28480 1853 0659 012 1854 1177 6 TRANSISTOR NPN SI PD 625MW FT 200MH2Z 28480 1854 1177 A3Q302 400 NOT ASSIGNED 401 1854 0813 5 2 TRANSISTOR NPN 2335015 SI 39 1W 28480 1854 0813 A3Q402 1853 0462 8 2 TRANSISTOR PNP 2N3635 SI TO 39 PD 1W 01295 2N3635 A30403 1853 0462 8 TRANSISTOR PNP 2N3635 SI TO 39 PD 1W 01295 2N3635 A3Q404 1854 0813 5 TRANSISTOR NPN 2N3501S 1 39 1W 28480 1854 0813 A3Q405 1854 1177 6 TRANSISTOR NPN SI PD 625MW FT 200MHZ 28480 1854 1177 A3Q406 1853 0659 5 TRANSISTOR 1 PD 625MW FT 200MHZ 28480 1853 0659 A304072 1854 1177 6 TRANSISTOR NPN SI 625MW FT 200MHZ 28480 1854 1177 A3Q4084 1853 0659 5 TRANSISTOR PNP 1 PD 625MW FT 200MHZ 28480 1853 0659 A3R1 1810 0204 6 1 NETWORK RES 8 SIP 1 0K OHM X 7 11236 750 81 F1K 2 0698 7236 7 2 RESISTOR 1K 196 OSW F TC 0 100 24546 C3 1 8 T0 1001 F 0757 0417 8 2 RESISTOR 562 196 125W TC 04 100 24546 CT4 1 8 T0 562R F ASR4 0698 7248 1 8 RESISTOR 3 16K 1 OSW TC 0 100 24546 C3 1
52. 2 8 RESISTOR 1K 1 125W 0 25 28480 0698 6362 A3R416 0698 8822 9 1 RESISTOR 6 81 1 125W F TC 0 100 28480 0698 8822 A3R417 0757 0462 3 2 RESISTOR 75K 1 125W TC 0 100 24546 CT4 1 8 T0 7502 F A3R418 2100 3659 7 RESISTOR TRMR 20K 10 C TOP ADJ 17 TRN 28480 2100 3659 A3R419 0757 0401 0 2 RESISTOR 100 1 125W F TC 0 100 24546 CT4 1 8 TO 101 F A3R420 0757 0401 0 RESISTOR 100 1 125W F TC 0 100 24546 CT4 1 8 TO 101 F 421 0698 6362 8 RESISTOR 1K 1 125W 0 25 28480 0698 6362 422 0757 0462 3 RESISTOR 75K 1 125W TC 0 100 24546 4 1 8 0 7502 423 0757 0280 3 2 RESISTOR 1K 1 125W F TC 0 100 24546 4 1 8 0 1001 424 0757 0280 3 RESISTOR 1K 1 125W TC 0 100 24546 CT4 1 8 TO 1001 F ASR425 445 A3R446 0698 6624 5 2 RESISTOR 2K 1 125W 0 25 28480 0698 6624 447 0699 1728 2 2 RESISTOR 2 652K 1 12W 28480 0699 1728 A3R448 0698 6624 5 RESISTOR 2K 1 125W 0 25 28480 0698 6624 A3R449 0699 1728 2 RESISTOR 2 652K 1 12W 28480 0699 1728 A3R450 NOT ASSIGNED 451 NOT ASSIGNED A3R452 0698 3430 5 4 RESISTOR 21 5 1 125W F TC 0 100 03888 PME55 1 8 TO 21R5 F A3R453 0698 3430 5 RESISTOR 21 5 1 125W 0 100 03888 55 1 8 0 2185 A3R454 0699 1726 0 2 RESISTOR 1 150K 1 12W 28480 0699 1726 455 0698 6348 0 RESISTOR 1 125W 0 25 28480 0698 6348 ASR456 0698 6348 0 RESISTOR 19 125W 0 25 28480 0698 6348 A3R457 06
53. 217 0698 7277 6 RESISTOR 51 1K 1 05W 0 100 24546 C3 1 8 T0 5112 F A3R218 0698 7277 6 RESISTOR 51 1K 1 05W TC 0 100 24546 C3 1 8 TO 5112 F A3R219 0698 7277 6 RESISTOR 51 1K 1 05W TC 0 100 24546 C3 1 8 T0 5112 F A3R220 0698 7284 5 1 RESISTOR 100K 1 05W TC 0 100 24546 C3 1 8 T0 1003 F 221 0698 7198 0 1 RESISTOR 26 1 1 05W 0 100 24546 C3 1 8 TO 26R1 F A3R222 0698 7220 9 1 RESISTOR 215 1 05W TC 0 100 24546 C3 1 8 TO 215R F 223 0698 7205 0 RESISTOR 51 1 1 05 0 100 24546 C3 1 8 TO 51R1 F A3R224 2100 3296 8 1 RESISTOR TRMR 1K 10 TOP ADJ 17 TRN 28480 2100 3296 225 0698 7248 1 RESISTOR 3 16K 1 05W TC 0 100 24546 C3 1 8 T0 3161 F A3R226 0698 7248 1 RESISTOR 3 16K 1 05 TC 0 100 24546 C3 1 8 T0 3161 F 227 0757 0394 Q 3 RESISTOR 51 1 1 125 0 100 24546 CT4 1 6 TO 51R1 F A3R228 0698 7277 6 RESISTOR 51 1K 1 05W TC 0 100 24546 C3 1 8 T0 5112 F A3R229 2100 3659 7 2 RESISTOR TRMR 20K 10 C TOP ADJ 17 TRN 28480 2100 3659 A3R230 0698 3457 6 1 RESISTOR 316K 1 125W F TC 0 100 28480 0698 3457 TRefer to Section 7 for update information Factory Selected Component Refer to Section 5 Replaceable Parts Model 8904A Table 6 3 Replaceable Parts Reference HP Part infi Mfr Designation Number D Qty Description Code Mfr Part Number A3R231 0698 7275 4 1 RESISTOR 42 2K 1 05W 0 100 24546 C3 1 8 T0 4222 F A3R232 0698 7260 7 RESISTOR 10K 1 0
54. 3 A6R7 0757 0180 2 1 RESISTOR 31 6 1 125W F TC 0 100 28480 0757 0180 A6VR1 1902 0960 6 2 DIODE ZNR 12V 5 DO 35 PD 4W TC 077 28480 1902 0960 A6VR2 1902 0960 6 2 DIODE ZNR 12V 5 DO 35 PD 4W TC 077 28480 1902 0960 tRefer to Section 7 for update information Factory Selected Component Refer to Section 5 Errata part change rev 0INOV89 6 17 Replaceable Parts Model 8904A Table 6 3 Replaceable Parts Reference HP Part infi Mfr Designation Number D Qty Description Code Mi Part Number A7 A9 NOT ASSIGNED A10 Note The A10 and A3 Assemblies are identical Refer to A3 for individual component part numbers Refer to Section 7 for update information Factory Selected Component Refer to Section 5 A Errata part change 6 18 rev 01NOV89 Model 8904A Replaceable Parts Table 6 3 Replaceable Parts Reference HP Part mfi Mfr Designation Number D Qty Description Code Mir Parn Number Miscellaneous Parts B1 08904 61010 5 1 FAN ASSY 12VDC 28480 08904 61010 F1 2110 0003 0 1 FUSE 3A 250V NTD 1 25X 25 UL 75915 312003 INCLUDED WHEN ORDERING W1 2712A to 2917A S1 3101 2216 3 1 SWITCH PB DPDT ALTING 4A 250VAC 28480 3101 2216 INCLUDED WHEN ORDERING W1 5041 1682 9 t KEYCAP FOR LINE SWITCH INCLUDED WHEN ORDERING W1 2923A and above S1 3101 2216 3 1 SWITCH PB DPDT ALTING 4A 250VAC 28480 3101 2216 INCLUDED WHEN ORDERING W1 0371 3802 3 1 KEYCAP FOR LINE SWITCH INCLUDED WHEN ORDERING W1 T1 9100 4833 8
55. 3 Replaceable Parts Description DIODE SWITCHING 80V 200MA 2NS 00 35 DIODE SWITCHING 80V 200MA 2NS 00 35 CONN POST TYPE 100 PIN SPCG 34 CONT NOT ASSIGNED CONNECTOR 3 PIN M POST TYPE JUMPER REMOVABLE FOR 0 025 IN SQ PINS CONNECTOR RF SMC PC 50 CONNECTOR RF SMC M PC 50 OHM CONNECTOR RF SMC M PC 50 OHM CONNECTOR POST JUMPER REMOVABLE FOR 0 025 IN SQ PINS NOT ASSIGNED CONNECTOR 3 PIN M POST TYPE JUMPER REMOVABLE FOR 0 025 IN SQ PINS ADDED FOR OPTION 006 NOT ASSIGNED CONNECTOR POST JUMPER REMOVABLE FOR 0 025 IN SQ PINS NOT ASSIGNED CONNECTOR RF SMC PC 50 CONNECTOR RF SMC M PC 50 OHM RELAY REED 1A 500MA 100VDC 5VDC COIL RELAY REED 1A 500MA 100VDC 5VDC COIL RELAY REED 500MA 100VDC 5VDC COIL RELAY REED 500MA 100VDC 5VDC COIL RELAY REED 1A 500MA 100VDC 5VDC COIL RELAY REED 1A 500MA 100VDC 5VDC COIL NOT ASSIGNED RELAY 2C 5VDC COIL 5A 125 NOT ASSIGNED RELAY REED 1A 500MA 100VDC 5VDC COIL RELAY REED 1A 500MA 100VDC 5VDC COIL NOT ASSIGNED RELAY REED 1A 500MA 100VDC 5VDC COIL RELAY REED 2A 2A 100VDC 5VDC COIL 200VA RELAY REED 2A 2A 100VDC SVDC COIL 200VA INDUCTOR RF CH MLD 5 6UH 596 INDUCTOR RF CH MLD 470NH 5 INDUCTOR RF CH MLD 470NH 5 INDUCTOR RF CH MLD 8 2MH 5 INDUCTOR RF CH MLD 8 2MH 5 INDUCTOR RF CH MLD 160UH 5 CL V MIN 74 1UH CL V MIN 72 6UH CL V MIN 60 7UH INDUCTOR RF CH MLD 2 7MH 5 CL V MIN 58 1UH INDUCTOR RF CH
56. 3A Factory Selected Component Refer to Section 5 Model 8904A Replaceable Parts Table 6 3 Replaceable Parts Reference HP Part Descripti Mfr Qty scription Mfr Part Number Designation Number D Code 4 08904 61001 4 1 POWER SUPPLY ASSEMBLY 28480 08904 61001 AS 1990 1197 8 1 LCD ASSEMBLY 28480 1990 1197 2712A TO 2942A NOT ASSIGNED 2948A and above 08904 50104 6 1 TRANSFORMER BOARD 28480 08904 60104 ADDED FOR OPTION 006 A6C1 0160 4822 2 1 CAPACITOR FXD 1000PF 5 100VDC CER 28480 0160 4822 A6C2 0160 4810 8 CAPACITOR FXD 5 100VDC CER 28480 0160 4810 0160 4805 1 CAPACITOR FXD 47PF 5 100VDC CER 04 30 28480 0160 4805 A6J1 1250 0836 2 4 CONNECTOR RF SMC M PC 50 OHM 28480 1250 0836 A6J2 1250 0836 2 CONNECTOR RF SMC M PC 50 OHM 28480 1250 0836 A6J3 1250 0836 2 CONNECTOR RF SMC M PC 50 OHM 28480 1250 0836 A6J4 1250 0836 2 CONNECTOR RF SMC M PC 50 OHM 28480 1250 0836 6 5 1252 2235 3 CONNECTOR POST 100 PIN SPCG 6 CONT 28480 1252 2235 A6R1 2100 0545 4 1 RESISTOR TRMR 1K 10 C SIDE ADJ 17 TURN 32997 3292X 1 102 AGR2 0757 0280 3 1 RESISTOR 1K 1 125W F TC 0 100 24546 CT4 1 8 TO 1001 F A6R3 0757 0420 3 1 RESISTOR 750 1 125W F TC 0 100 24546 CT4 1 8 TO 751 F A6R4 0757 0290 5 1 RESISTOR 6 19K 1 125W F TC 0 100 19701 MF4C1 8 T0 6191 F 6 5 2100 3755 4 1 RESISTOR TRMR 50 10 C SIDE ADJ 17 TURN 28480 2100 3755 AGRE 0698 8823 0 1 RESISTOR 8 25 1 125 TC 0 100 28480 0698 882
57. 515 1234 80 0515 1234 F SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 81 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 2712A to 2917A 82 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 83 0515 1234 7 SCREW MACH M3 5 0 6 8MM LG 28480 0515 1234 2923A and above 82 NOT ASSIGNED SEE ITEM 145 83 NOT ASSIGNED Refer to Section 7 for update information Factory Selected Component Refer to Section 5 Errata part change rev O1JUL91 6 21 Replaceable Parts Reference Designation 84 85 86 87 88 102 103 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 HP Part Number 0515 1234 0361 1265 0361 1265 0361 1265 0361 1265 5021 8415 0515 1860 0515 1860 0515 1860 0515 1860 0515 1860 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 08904 61013 2190 0585 0515 0955 0380 1914 0380 1914 0380 1914 0380 1914 0380 1914 0380 1914 gt CO Mc ah Qty tRefer to Section 7 for update information 6 22 Table 6 3 Replaceable Parts Description SCREW MACH M3 5 X 0 6 8MM LG RIVET BLIND PL STEM DOME HD 125DIA RIVET BLIND PL STEM DOME HD 125DIA RIVET BLIND PL STEM DOME HD 125DIA RIVET BLIND PL STEM DOME HD 125DIA FRAME FRONT SCREW MACHINE ASSEM
58. 5W TC 0 100 24546 C3 1 8 T0 1002 F 233 0698 7260 7 RESISTOR 10K 1 05W 0 100 24546 3 1 8 0 1002 234 299 NOT ASSIGNED A3R300 0698 7248 1 RESISTOR 3 16K 1 05W F TC 0 100 24546 C3 1 8 T0 3161 F 01 0698 7248 1 RESISTOR 3 16 1 05W 0 100 24546 C3 1 8 T0 3161 F A3R302 399 NOT ASSIGNED A3R400 0698 8821 8 4 RESISTOR 5 62 1 125W F TC 0 100 28480 0698 8821 401 0698 8821 8 RESISTOR 5 62 1 125W TC 0 100 28480 0698 8821 402 0698 8821 8 RESISTOR 5 62 1 125W TC 0 100 28480 0698 8821 A3R403 NOT ASSIGNED A3R404 0698 7240 3 4 RESISTOR 1 47K 1 05W F TC 0 100 24546 C3 1 8 T0 1471 F ASR405 0698 7267 4 4 RESISTOR 19 6K 1 05W TC 0 100 24546 C3 1 8 T0 1962 F A3R406 0698 7267 4 RESISTOR 19 6 1 05W F TC 0 100 24546 C3 1 8 T0 1962 F A3R407 0698 7240 3 RESISTOR 1 47 1 05W TC 0 100 24546 C3 1 8 T0 1471 F A3R408 0698 7240 3 RESISTOR 1 47 1 05W TC 0 100 24546 C3 1 8 T0 1471 F A3R409 0698 7267 4 RESISTOR 19 6K 1 05W TC 0 100 24546 C3 1 8 T0 1962 F A3R410 0698 7267 4 RESISTOR 19 6K 1 05W TC 0 100 24546 C3 1 8 T0 1962 F 411 0698 7240 3 RESISTOR 1 47K 1 05W TC 0 100 24546 C3 1 8 T0 1471 F A3R412 0698 6362 8 3 RESISTOR 1K 1 125W F TC 0 25 28480 0698 6362 A3R413 0698 6317 3 2 RESISTOR 500 1 125W 0 25 03888 55 1 8 79 5008 414 0698 6317 3 RESISTOR 500 1 125W 0 25 03888 55 1 8 9 5008 415 0698 636
59. 60 4801 7 CAPACITOR FXD 100 5 100VDC CER 28480 0160 4801 448 0160 4801 7 CAPACITOR FXD 100 5 100VDC CER 28480 0160 4801 A3C449 499 NOT ASSIGNED A3C500 0160 3879 7 CAPACITOR FXD 01UF 20 100VDC CER 28480 0160 3879 501 0160 3879 7 CAPACITOR FXD 01UF 20 100VDC CER 28480 0160 3879 A3C502 0160 3879 7 CAPACITOR FXD O1UF 20 100VDC CER 28480 0160 3879 A3C503 0160 3879 7 CAPACITOR FXD 01UF 20 100VDC 28480 0160 3879 A3C504 0160 4789 0 CAPACITOR FXD 15PF 5 100VDC CER 0 30 28480 0160 4789 505 0160 4824 4 1 CAPACITOR FXD 680PF 5 100VDC CER 28480 0160 4824 1 5 NOT ASSIGNED A3CRE 1901 0028 5 4 DIODE PWR RECT 400V 750MA DO 29 28480 1901 0028 A3CR7 1901 0028 5 DIODE PWR RECT 400 750MA 00 29 28480 1901 0028 ASCRB 1901 0050 3 25 DIODE SWITCHING 80V 200MA 2NS DO 35 9N171 1N4150 ASCRS 1901 0050 3 DIODE SWITCHING 80V 200MA 2NS DO 35 9N171 1N4150 TRefer to Section 7 for update information Factory Selected Component Refer to Section 5 6 8 Model 8904A Reference Designation 10 16 A3CR17 18 19 25 26 27 A3CR28 201 A3CR202 A3CR203 204 A3CR205 ASCR206 A3CR207 ASCR208 209 A3CR210 A3CR211 A3CR212 A3CR213 299 A3CR300 A3CR301 A3CR302 403 A3CR404 A3CR405 A3CR406 A3CR407 A3CR408 A3CR409 410 411 412 414 2712 to 2747 415 ASCR416 ASCR417 ASCR418 2817A and above
60. 60 6883 A3C38 0160 3875 3 1 CAPACITOR FXD 22PF 5 200VDC CER 0 30 28480 0160 3875 A3C39 NOT ASSIGNED A3C40 0160 4835 7 16 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4835 41 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 42 0160 4835 7 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4835 43 0160 4822 2 1 CAPACITOR FXD 1000PF 5 100VDC CER 28480 0160 4822 44 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 45 0160 4812 0 1 CAPACITOR FXD 220PF 5 100VDC CER 28480 0160 4812 46 0160 4835 7 CAPACITOR FXD 1UF 10 CER 28480 0160 4835 47 0160 4835 7 CAPACITOR FXD 1UF 10 50VDC CER 28480 0160 4835 A3C48 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 49 ASSIGNED 50 0160 4835 7 CAPACITOR FXD 1UF 10 CER 28480 0160 4835 51 0160 6884 0 1 CAPACITOR FXD 270PF 1 100VDC CER 28480 0160 6884 52 63 ASSIGNED 64 0160 4535 4 1UF 10 50 0 CER 28480 0160 4535 A3C65 70 NOT ASSIGNED 71 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 72 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 79 0160 4832 4 CAPACITOR FXD OTUF 10 100VDC CER 28480 0160 4832 A3C82 0160 4832 4 CAPACITOR FXD 01UF 10 100VDC CER 28480 0160 4832 tRefer to Section 7 for update information Factory Selected Component Refer to Section 5 A Errata pa
61. 701 91637 91637 28480 28480 28480 28480 28480 24546 24546 28480 24546 24546 24546 24546 28480 28480 15542 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 01295 01295 01295 Replaceable Parts Mfr Part Number 0698 6348 55 1 8 0 215 PMES5 1 8 T0 21R5 F 0699 1726 5033R 1 8 TO 12R1 F 5033R 1 8 TO 12R1 F 5033R 1 8 TO 12R1 F 5033R 1 8 TO 12R1 F NS 1 2 NS 1 2 0698 8827 0757 0123 0757 0199 0698 8827 0757 0123 CT4 1 8 T0 1781 F CT4 1 8 T0 1781 F 0757 0199 4 1 8 0 2611 CT4 1 8 T0 2611 F 4 1 8 0 51 1 CT4 1 8 TO 51R1 F 0698 8821 08904 80004 T1 1T X65 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 SN74ALS74AN SN74ALS174N SN74ALS174N Factory Selected Component Refer to Section 5 Replaceable Parts Reference Designation A3U6 A3U7 A3U8 A3U9 011 15 016 A3U17 200 A3U201 0202 A3U203 A3U204 400 A3U401 A3U402 A3U403 A3U404 A3U405 407 A3U408 18 A3VR19 A3VR20 30 A3VR31 A3VR32 200 201 202 205 206 A3VR207 208 209 400 A3VR401 A3VR402 6 16 HP Part Number 1826 1013 1858 0047 1826 1049 1858 0047 1810 0556 1901 1011 1826 1067 1826 1557 1826 1665 1826 1665 1826 1665 1826 1067 1826 0759 1902 0967 1902 0962 1902
62. 8 T0 3161 F 5 0698 7248 1 RESISTOR 3 16K 1 OSW F TC 0 100 24546 C3 1 8 T0 3161 F Refer to Section 7 for update information Factory Selected Component Refer to Section 5 A Errata part change rev 01JUL91 6 11 Replaceable Parts Model 8904 Table 6 3 Replaceable Parts Reference HP Part inti Mfr Designation Number D Qty Description Code Mfr Part Number A3R6 8 NOT ASSIGNED A3R9 0698 7205 0 5 RESISTOR 51 1 1 05W 0 100 24546 C3 1 8 TO 51R1 F A3R10 0698 7205 0 RESISTOR 51 1 1 05W TC 0 100 24546 C3 1 8 TO 51R1 F A3R11 39 NOT ASSIGNED A3R40 0698 6782 6 5 RESISTOR 250 1 125W TC 0 25 28480 0698 6782 A3R41 0698 6782 6 RESISTOR 250 1 125W 0 25 28480 0698 6782 A3R42 0698 8819 4 1 RESISTOR 3 83 1 125W 0 100 28480 0698 8819 A3R43 0698 6782 6 RESISTOR 250 1 125W 0 25 28480 0698 6782 A3R44 0698 6782 6 RESISTOR 250 1 125W 0 25 28480 0698 6782 5 0698 7268 5 1 RESISTOR 21 5K 1 05W TC 0 100 24546 C3 1 8 T0 2152 F A3R46 NOT ASSIGNED A3R47 0698 6782 6 RESISTOR 250 1 125W F TC 0 25 28480 0698 6782 A3R48 0698 6320 8 1 RESISTOR SK 1 125W 0 25 03888 55 1 8 9 5001 0698 7260 7 4 RESISTOR 10K 1 05W TC 0 100 24546 C3 1 8 T0 1002 F A3R50 0698 7280 1 1 RESISTOR 68 1K 1 05W TC 0 100 24546 C3 1 8 T0 6812 F 51 0698 7232 3 7 RESISTOR 681 1 05W 0 100 24546 C3 1 8 TO 681R F 52 0698 7256 1 2 RESIS
63. 80 1901 0880 1 4150 1 4150 1 4150 1 4150 185312 1 5312 1 5312 1 5312 1 4150 1 4150 Factory Selected Component Refer to Section 5 Replaceable Parts Reference Designation A3CR429 A3CR430 A3J1 A3J2 A3J3 ANS ANE A3J7 2712A to 2942A J8 2948A and above A3J8 A3J9 J200 A3J201 A3J202 J399 A3J400 A3J401 A3K1 A3K2 A3K4 A3K5 A3K6 A3K7 A3K8 A3K9 A3K10 A3K11 A3K12 400 A3K401 A3K402 A3K404 A3L1 A3L2 A3L3 A3L4 A3L5 A3L6 A3L7 18 ASLO A3L10 A3L11 A3L12 A3L13 200 A3L201 A3L401 A3L402 A3MP1 2 A3MP3 5 tRefer to Section 7 for update information 6 10 HP Part Number 1901 0050 1901 0050 1251 8601 1251 4670 1258 0141 1250 0835 1250 0835 1250 0835 1251 4670 1258 0141 1251 4670 1258 0141 1251 4670 1258 0141 1250 0836 1250 0836 0490 1608 0490 1608 0490 1608 0490 1608 0490 1608 0490 1608 0490 1190 0490 1608 0490 1608 0490 1608 0490 1501 0490 1501 9100 3560 9100 3548 9100 3548 9100 1675 9100 1675 9100 1640 08904 80001 08904 80005 08904 80002 9100 1663 08904 80003 9100 3551 9100 3560 9140 0454 9100 3315 1205 0213 1205 0213 1205 0213 1205 0213 0340 0834 to i Uu ohh hp Qty Table 6
64. 800 with part number 0698 0085 26100 4 5 Replace A3R491 and A3R493 34 8 with part number 0757 0199 21 5 If the instrument has Option 002 a second output the same modification should be made to the 10 assembly Parts List 0698 0085 0 2 Fixed Resistor 26100 0757 0199 3 2 Fixed Resistor 21 5 1901 0880 7 4 Diode If the instrument has Opt 002 order twice this quantity Firmware Updates Hardware Modifications 7 13 Instrument Changes Model 8904A 7 9 MODIFICATION FOR POTENTIAL POWER SUPPLY SHORT Serial Prefix 2817A and below A problem has been noted in HP 8904A Multifunction Synthesizers with Option 002 a second output and with serial prefix 2817A and below In these instruments it is possible for the heatsinks on the output transistors on the 10 Output Assembly installed only in Option 002 to touch the bottom cover when the instrument is jarred If the instrument is jarred often enough the anodization an insulator on the heatsinks will wear through and could make electrical contact with the cover Should this occur while the instrument is on a 16 V power supply may short to ground This may cause the power supply fuse to blow or it may intermittently cause the following error to be displayed Reference Loop Reports Out Of Lock To prevent or solve this problem it is recommended that an insulator HP part 08904 00015 be installed on the inside of the bottom cove
65. 89 Model 8904A Instrument Changes 7 5 REAR TO FRONT PANEL OUTPUT CONVERSION Description This procedure describes how to convert an instrument with rear panel output connectors that is Option 004 to one with front panel connectors that is a standard instrument The procedure applies to instruments with one pair of outputs or two that is Option 002 The modifications requires partial disassembly f the instrument removing covers and routing of cables No soldering is required Modification should be done in a static protected environment After modification two performance tests must be run Parts Required The following parts are required and may be ordered by contacting the nearest Hewlett Packard Sales Office Table 7 2 Parts for HP 8904A Rear to Front Panel Output Conversion Standard Plastic Hole Plug 6960 0132 Option 002 Plastic Hole Plug 6960 0132 Cable Tie 1400 0249 Tools Required The following tools are needed to modify the instrument 9 16 inch 6 point Nut Driver No 2 Pozidriv Screwdriver Diagonal Cutters Needle nose Pliers Modification Procedure Removing Bottom Cover 1 Turn the instrument off and unplug the power cord 2 Lay the instrument on its top and unscrew the Pozidriv screw in the middle of the rear edge of the bottom cover This is a captive screw and will cause the bottom cover to push away from the frame Slide the cover back about 6 5 mm 0 25 inch and lift it off Prepari
66. 9 8 RESISTOR 511 1 05 TC 0 100 24546 C3 1 8 TO 511R F A3R139 0698 7229 8 RESISTOR 511 1 05W 0 100 24546 C3 1 8 TO 511R F A3R140 NOT ASSIGNED A3R141 0698 7248 1 RESISTOR 3 16K 1 05W F TC 0 100 24546 C3 1 8 TO 3161 F A3R142 0698 7219 6 RESISTOR 196 1 05W F TC 0 100 24546 C3 1 8 TO 196R F 143 200 NOT ASSIGNED A3R201 0698 7232 3 RESISTOR 681 1 05W TC 0 100 24546 C3 1 8 TO 681R F A3R202 0698 7232 3 RESISTOR 681 1 05W F TC 0 100 24546 C3 1 8 TO 6B1R F A3R203 0698 7232 3 RESISTOR 681 1 05W 0 100 24546 C3 1 8 TO 681R F A3R204 0698 7232 3 RESISTOR 681 1 OSW 0 100 24546 C3 1 8 TO 681R F A3R205 0698 7205 0 RESISTOR 51 1 1 05W TC 0 100 24546 C3 1 8 TO 51R1 F A3R206 0698 7205 0 RESISTOR 51 1 1 05W TC 0 100 24546 C3 1 8 TO 51R1 F A3R207 0698 7256 1 RESISTOR 6 81K 1 05W 0 100 24546 C3 1 8 T0 6811 F A3R208 0698 7257 2 1 RESISTOR 7 5K 1 05W TC 0 100 24546 3 1 8 0 7501 A3R209 0757 0420 3 1 RESISTOR 750 1 125W F TC 0 100 24546 CT4 1 8 T0 751 F A3R210 0698 6616 5 RESISTOR 750 1 125W F TC 0 25 28480 0599 6016 211 0698 7229 8 RESISTOR 511 1 05W TC 0 100 24546 C3 1 8 TO 511R F 212 0698 7229 8 RESISTOR 511 1 05 TC 0 100 24546 C3 1 8 TO 511R F 213 0698 7225 4 1 RESISTOR 348 1 05W TC 0 100 24546 C3 1 8 TO 348R F A3R214 NOT ASSIGNED 215 NOT ASSIGNED A3R216 0698 7277 6 5 RESISTOR 51 1K 1 05W F TC 0 100 24546 C3 1 8 T0 5112 F A3R
67. 98 6348 0 RESISTOR 1 125W TC 0 25 28480 0698 6348 Refer to Section 7 for update information Factory Selected Component Refer to Section 5 6 14 Model 8904A Reference Designation A3R458 A3R459 A3R460 A3R461 A3R462 465 A3R466 A3R467 A3R468 A3R469 A3R470 A3R471 A3R472 489 A3R490 2712A to 2747A A3R491 2817A and above A3R491 A3R492 2712A to 2747A 493 438494 438495 2817 and above A3R493 ASR494 A3R495 496 A3R497 A3R498 499 1 2 399 A3T400 2 4 5 A3TP7 9 401 402 403 A3U1 A3U2 4 A3U5 TRefer to Section 7 for update information rev 17MAY88 HP Part Number 0698 6348 0698 3430 0698 3430 0699 1726 0757 0379 0757 0379 0757 0379 0757 0379 0811 3726 0811 3726 0698 8827 0757 0123 0757 0199 0698 8827 0757 0123 0757 0278 0757 0278 0757 0199 0698 0085 0698 0085 0757 0394 0757 0394 0698 8821 08904 80004 9100 4444 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1251 0600 1820 2488 1820 3465 1820 3465 La 10 Table 6 3 Replaceable Parts Description RESISTOR 3K 1 125W F TC 0 25 RESISTOR 21 5 1 125W F TC 0 100 RESISTOR 21 5 1 125W F TC 0 100 RESISTOR 1 150K 1 12W NO
68. AND 24 dB ATTENUATORS TO 2 J1 25 MISCELLANEOUS CONTROL 2 J123 Jii 1 4 6232 6 COMP QUT 18 R78 552 7 968K R71 R72 1 133 1 133 f 12 dB ATTENUATOR 1 4 E ND SEE NOTE 16 Vpp R73 1 875K R74 R75 1 667 1 667 ADDITIONS TO INITIAL INSTRUMENT SETTINGS AMPTO 625 mV MEASURE 1 12 Vpp 6 dB ATTENUATOR SEE NOTE ADDITIONS TO INITIAL INSTRUMENT SETTINGS 2 5 MEASURE 4 6 R76 3 8080K 3 000 9 ADDITIONS INSTRUMEN 5 MEASURE 5 SEE NOTED TO INITIAL SETTINGS 9 Vpp ON OFF FLOATING AMP DRIVER AND ON OFF SWITCH SVREF SVUC 1 R1G 1K AME 6 1 P O K4g1 5VDC ADDITIONS TO INITIAL INSTRUMENT SETTINGS FOR A3 FOR 18 BHIFT OUTPUT 1 OFF SHIFT OUTPUT 2 OFF MEASURE Vpp SEE NOTE 18 gt 15v0C 15VDC C482 R415 481 1 BOK 180 oc OFFSET R416 R422 R417 28K 261K 261K 17 TURN CW R412 R413 1 B K 588 8 C494 g 1U R421 1 BBK 7 1 R414 C NC s g f AD 884 553 8 55 Service 8904 A3 Component Coordinates 2 of 2 A3 Component Coordinates 1 of 2 TPA we 0284 i aer TP6 ARE NOTES Figure 8 16 0487 ER
69. BLY M3 5 X 0 6 SCREW MACHINE ASSEMBLY M3 5 X 0 6 SCREW MACHINE ASSEMBLY M3 5 X 0 6 SCREW MACHINE ASSEMBLY M3 5 X 0 6 SCREW MACHINE ASSEMBLY 5 X 0 6 CABLE 062 625 DIA 091 WD NYL CABLE TIE 062 625 DIA 091 WD NYL CABLE TIE 062 625 DIA 091 WD NYL CABLE TIE 062 625 DIA 091 WD NYL CABLE TIE 062 625 DIA 091 WD NYL CABLE TIE 062D 09W ADDED FOR OPTION 004 CABLE TIE 062D 09W ADDED FOR OPTION 004 CABLE TIE 062D 09W ADOED FOR OPTION 004 SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG AY SHLD OUT PUT WASHER LK HLCL 3 5 MM 3 6 MM ID ADDED FOR OPTION 002 SCREW MACH M3 5 X 0 6 30MM LG PAN HD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 SPACER RND 19 MM LG 5 6 MM ID 10 MM OD ADDED FOR OPTION 002 Mfr Code 28480 90201 90201 90201 90201 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480
70. DED FOR OPTION 004 CABLE TIE 062D 09W ADDED FOR OPTION 004 CABLE TIE 062D 09W ADDED FOR OPTION 004 CABLE TIE 062 625 DIA 091 WD NYL CABLE TIE 062D 09W ADDED FOR OPTION 002 OUTPUT ASSEMBLY SHIELD ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 SCREW 3 0 6 SEM PNTX ADDED FOR OPTION 002 NOT ASSIGNED INSULATOR EPOXY GLASS Mfr Code 06540 06540 28480 28480 28480 28480 28480 28480 28480 28480 28480 00000 00000 00000 00000 00000 00000 00000 00000 00000 Factory Selected Component Refer to Section 5 Replaceable Parts Mfr Part Number 19666 0056 19616 0040 28 1400 0249 7120 4295 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 1400 0249 08904 61013 ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION A Errata part change 6 22 1 Replaceable Parts Reference Designation 2712A to 2917A 140 141 2923A and above 140 141 2912A 2917A 142 145 2923A and above
71. EL Active High Output Active Low Input 1 ACTIVE LOW inputs and outputs are indicated by the pres ence of the polarity indicator symbol ACTIVE ly LEVEL Active Low Output EDGE SENSITIVE INPUTS INPUT NA EDGE SENSITIVE low to high inputs are by the presence of the dynamic indicator symbol Low to High OUTPUT Edge Sensitive INPUT EDGE SENSITIVE high to low inputs are indicated by the presence of both the dynamic indicator the polarity i dicator symbols High to Low OUTPUT Edge Sensitive DELAYED OUTPUT RESPONSE OUTPUT indi Delayed Output OUTPUT DELAY indicator symbol 71 shows that the out Active High Input put becomes effective after the input signal returns to its i inactive state Delayed Output 1 Active Low Input 1 INHIBIT INPUTS INHIBIT indicator symbol indicates an input that when active inhibits blocks the output s from achieving their active states the outputs remain inactive ANALOG LINES ANALOG indicator symbol f indicates a line that has an analog input or output NONLOGIC CONNECTION The Nonlogic Connection symbol X indicates a connec tion that does not carry any logic information Service Model 8904A Table 8 1 Schematic Diagram Notes 11 of 11 The input that controls or gates other inputs is labeled with
72. ESCRIPTION USED FOR OPTION 002 60 2950 0035 8 NUT HEX DBL CHAM 15 32 32 THD 00000 ORDER BY DESCRIPTION USED FOR OPTION 006 61 5001 0539 9 2 TRIM SIDE FRT F SEE SECTION 7 28480 5001 0539 62 5001 0539 9 TRIM SIDE FRT F SEE SECTION 7 28480 5001 0539 63 5041 8801 8 4 FOOT FULL 1 2MOD SEE SECTION 7 28480 5041 8801 64 5041 8801 8 FOOT FULL 1 2MOD SEE SECTION 7 28480 5041 8801 65 5041 8801 8 FOOT FULL 1 2MOD SEE SECTION 7 28480 5041 8801 66 5041 8801 8 FOOT FULL 1 2MOD SEE SECTION 7 28480 5041 8801 67 5041 8803 1 TRIM STRIP SEE SECTION 7 28480 5041 8803 68 180 1871 2 LBL BLK SERIAL 28480 5180 1871 69 08904 00016 3 1 COVER TOP SEE SECTION 7 28480 08904 00016 70 08904 00017 4 1 COVER BOTTOM SEE SECTION 7 28480 08904 00017 71 1460 1345 5 2 TILT STAND SST 28480 1460 1345 72 1460 1345 5 TILT STAND SST 28480 1460 1345 2712A to 2917A 73 i 0515 0367 5 2 SCREW MACHINE ASSEMBLY 2 5 X 0 45 00000 ORDER BY DESCRIPTION SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT 74 1 0515 0367 5 SCREW MACHINE ASSEMBLY M2 5 X 0 45 00000 ORDER BY DESCRIPTION SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT 2923A and above 73 NOT ASSIGNED 74 NOT ASSIGNED 75 0515 1234 7 10 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 76 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 77 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 78 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0515 1234 79 0515 1234 7 SCREW MACH M3 5 X 0 6 8MM LG 28480 0
73. It should be replaced every five years or whenever it shows signs of deterioration Replacing the battery must be done carefully so as to not interrupt the contents of the RAM If the RAM looses its contents the entire A2 Digital Assembly will have to be replaced because its serial number and option information will be lost Replacing the backup battery consists of unplugging and freeing the A2 Digital Assembly wiring a power supply and resistor to RAM power supply pin removing the old battery and soldering in the new one removing the power supply backup and re assembling the instrument The normal precautions against electrostatic discharge must be followed but do not place the A2 Digital Control Assembly on a conductive metal surface which could short the battery or the RAM power supply pin The substitute power supply must be floating the solder iron has a grounded tip All soldering is done with the HP8904A completely disconnected from the power line Do not apply too much heat to printed circuit connections when soldering The traces on the multilayer board are easily damaged Do not overstress the interconnecting cables Tools and Supplies Desoldering Tool Resistor 10 Needle Nose Pliers Solder Iron Power Supply Floating or 3V Battery Torx Driver Parts If the instrument has serial prefix 2942A and below order a 2 8V battery HP 1420 0281 and three insulators HP 3050 0990 If the instrument has serial prefix
74. ONTROL 41019 ova 41518 TO 2 OVERVOL TAGE CONTROL 4107 M N R1B 1K 5 0 Fad 83 FLOATING OUTPUT AMPLIFIER GAIN 1 12 R499 5 62 CR411 1 158K 6425 1 7 0P 16VDC 15 0 12VDC CR421 S HIGH FREQUENCY Fan BALANCE CR422 12vDC R449 2 052K V 6 od C437 C438 R469 8 910 6 8U 1S DC 48 dB ATTENUATOR ove ADDITIONS TO INITIAL INSTUMENT SETTINGS AMPTO 39 MEASURE 78 mVpp SET THE OSCILLOSCOPE TO REJECT HIGH FREQUENCIES TO ELIMINATE WAVEFORM FUZZINESS OVERVOLTAGE PROTECTION _ _ __ RELAY 7 DRIVER LOGIC 5VDC 5 0 5 0 5VREF R123 4 64K CR17 R122 46 4K ADDITIONG TO INITIAL INSTRUMENT SETTINGS AMPTO 1 V SHORT TESBTPOINTS Aid 1 482 ANO 4 TO GROUND THIS ISOLATES THE UPPER AND LOWER HALVES OF THE FLOATING OUTPUT AMPLIFIER gt SET THE OSCILLOSCOPE TO REJECT HIGH FREQUENCIES TO ELIMINATE WAYEFORM FUZZINESS CHECK THE VOLTAGE AT THE JUNCTION OF R4 amp 6 9457 MEASURE 1 5 CHECK THE VOLTAGE AT THE JUNCTION OF R468 ANO R469 MEASURE 1 4 18gP K4824 V OVERVOLTAGE RELAY DRIVE DETECTOR R496 81 1 R495 1 78 ova 1 5VREF V 2 0 K4g2 5VOC R491 34 OK V R493 34 BK
75. ROFIT KIT NOT ASSIGNED SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT NOT ASSIGNED SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG SCREW MACHINE ASSEMBLY M3 X 0 5 6MM LG NUT SPCLY 15 32 32 THD 1 IN THK 562 WD EXCEPT OPTION 006 NUT HEX DBL CHAM 15 32 32 THD USED FOR OPTION 006 NUT SPCLY 15 32 32 THD 1 IN THK 562 WD EXCEPT OPTION 006 NUT HEX DBL CHAM 15 32 32 THD USED FOR OPTION 006 PLUG HOLE 500D Mfr Code 28480 28480 28480 00000 00000 00000 28480 Factory Selected Component Refer to Section 5 Model 8904A Mfr Part Number 08904 61021 08904 40006 08904 00021 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 0515 1851 ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION ORDER BY DESCRIPTION 6960 0132 A Errata part change rev 01NOV89 Model 8904A Replaceable Parts Table 6 3 Replaceable Parts Reference HP Part Designation Number D Qty Description Code Mfr Part Number 56 6960 0132 1 PLUG HOLE 500D 28480 6960 0132 57 NOT ASSIGNED 582 NOT ASSIGNED 59 2950 0035 8 NUT HEX DBL CHAM 15 32 32 THD 00000 ORDER BY DESCRIPTION USED FOR OPTION 002 59 2950 0035 8 NUT HEX DBL CHAM 15 32 32 THD 00000 ORDER BY DESCRIPTION USED FOR OPTION 006 60 0590 1251 NUT SPCLY 15 32 32 THD 14N THK 562 WD 00000 ORDER BY D
76. STOR 1 133 1 125W 0 25 19701 5033R A3R72 0699 2235 8 RESISTOR 1 133K 1 125W TF TC 0 25 19701 5033R A3R73 0699 0106 8 1 RESISTOR 1 875K 1 125W TC 0 25 28480 0699 0106 A3R74 0699 2237 9 2 RESISTOR 1 667 1 125W 0 25 19701 5033R A3R75 0699 2237 0 RESISTOR 1 667K 1 125W 0 25 19701 5033R A3R76 0698 6616 5 2 RESISTOR 750 1 125W F TC 0 25 28480 0698 6616 A3R77 0698 6348 0 6 RESISTOR 1 125W TC 0 25 28480 0698 6348 A3R78 0698 6348 0 RESISTOR 1 125W 0 25 28480 0698 6348 79 111 NOT ASSIGNED A3R112 0699 2233 6 2 RESISTOR 50 4 1 5W 0 25 19701 5053R 113 0699 2236 9 1 RESISTOR 6 4K 1 125W TC 0 25 19701 5033R 6 12 TRefer to Section 7 for update information Factory Selected Component Refer to Section 5 Model 8904A Replaceable Parts Table 6 3 Replaceable Parts Reference HP Part ipti Mfr Designation Number D Qty Description Code Mfr Part Number 114 0699 2233 6 RESISTOR 50 4 1 5W 0 25 19701 5053R A3R115 121 NOT ASSIGNED A3R122 0698 7276 5 1 RESISTOR 46 4K 1 05W F TC 0 100 24546 C3 1 8 T0 4642 F A3R123 0698 7252 7 1 RESISTOR 4 64K 1 05W F TC 0 100 24546 C3 1 8 T0 4641 F 124 NOT ASSIGNED A3R125 0698 7266 3 1 RESISTOR 17 8K 1 05W TC 0 100 24546 3 1 8 0 1782 A3R126 0757 0417 8 RESISTOR 562 1 125W F TC 0 100 24546 CT4 1 8 T0 562R F A3R127 135 NOT ASSIGNED A3R136 0698 722
77. T ASSIGNEO RESISTOR 12 1 1 125W F TC 0 100 RESISTOR 12 1 1 125W F TC 0 100 RESISTOR 12 1 1 125W F TC 0 100 RESISTOR 12 1 1 125W F TC 0 100 RESISTOR 25 42 1 75W PW TC 0 20 RESISTOR 25 42 1 75W PW TC 0 20 NOT ASSIGNED RESISTOR 1M 1 125W F TC 0 100 RESISTOR 34 8K 1 125W F TC 0 100 RESISTOR 21 5K 1 125W F 0 100 RESISTOR 1M 1 125W F TC 0 100 RESISTOR 34 8K 1 125W F TC 0 100 RESISTOR 1 78K 1 RESISTOR 1 78K 1 RESISTOR 21 5K 1 RESISTOR 2 61K 1 RESISTOR 2 61K 1 125W TC 0 100 125W F TC 0 100 125 TC 0 100 125W TC 0 100 125W TC 0 100 RESISTOR 51 1 1 125W F TC 0 100 RESISTOR 51 1 1 125W F TC 0 100 NOT ASSIGNED RESISTOR 5 62 1 125W F TC 0 100 XFMR POT CORE NOT ASSIGNED TRANSFORMER RF INPUT IMP 50 OHMS INPUT CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 5 52 SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ NOT ASSIGNED CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ CONNECTOR SGL CONT PIN 1 14 MM BSC SZ SQ NOT ASSIGNED FF TTL ALS D TYPE POS EDGE TRIG NOT ASSIGNED IC FF TTL ALS D TYPE POS EDGE TRIG COM IC FF TTL ALS D TYPE POS EDGE TRIG COM Mfr Code 28480 03888 03888 28480 19701 19701 19701 19
78. T FLOAT 1 OFF None FLOAT 2 SHIFT FLOAT 2 OFF None SHIFT OUTPUT 1 OFF None SHIFT OUTPUT 2 OFF 3 HP IB Annunciators Check a On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in SHIFT SERVICE NEXT NEXT f3 Memory Map Access NEXT NEXT The four front panel HP IB annunciators RMT LSTN TALK and SRQ should be on Pins 15 14 18 and 12 respectively of U2 should all be T TL low b Key in 0 F The HP IB annunciators should be off Pins 15 14 13 and 12 of U2 should be high Table 8 3 A1 Interconnections to A2 Annunciators ene ree ran row Note J1 is the 22 pin connector on the front right edge of A2 Pin 1 is nearest the center of the board 5V supply is pins 1 and 2 of J1 8 40 Troubleshooting Digital Keyboard Interface Model 8904A Service A2 DIGITAL ASSEMBLY TO 5 DISPLAY ASSEMBLY INTERFACE Description A failure in the A5 Display Assembly can cause the entire instrument to hang up at power up this condition is suspected measure pin 12 of A2U25 or pin 4 of A2U20 with a high impedance dc coupled oscilloscope pulses should be seen with 1 us high and 15 low The signal is normally a TTL high To check the backlighting measure the connection of the red wire at A2J8 with a high impedance dc coupled oscilloscope A2J8 is located in the extreme front right side of A2 A
79. TOR 6 81K 1 05W 0 100 24546 3 1 8 0 6811 A3R53 0698 7208 3 1 RESISTOR 68 1 1 05W TC 0 100 24546 C3 1 8 TO 68R1 F 54 0698 7260 7 RESISTOR 10K 1 05W 0 100 24546 3 1 8 0 1002 55 0698 7283 4 1 RESISTOR 90 9K 1 05 TC 0 100 24546 C3 1 8 T0 9092 F A3R56 0698 7229 8 5 RESISTOR 511 1 05W 0 100 24546 C3 1 8 TO 511R F A3R57 0698 7231 2 1 RESISTOR 619 1 05W TC 0 100 24546 C3 1 8 TO 619R F 58 0698 7212 9 1 RESISTOR 100 1 05W TC 0 100 24546 C3 1 8 TO 100R F 59 0698 7239 0 1 RESISTOR 1 33K 1 05W 0 100 24546 3 1 8 0 1331 A3R60 0698 7243 6 1 RESISTOR 1 96K 1 05W TC 0 100 24546 C3 1 8 T0 1961 F A3R6t 0698 7219 6 2 RESISTOR 196 1 05W F TC 0 100 24546 C3 1 8 TO 196R F A3R62 0698 7232 3 RESISTOR 681 1 05W F TC 0 100 24546 C3 1 8 TO 681R F 0698 7232 3 RESISTOR 681 1 05W TC 0 100 24546 C3 1 8 TO 681R F A3R64 0698 7188 8 2 RESISTOR 10 1 05W TC 0 100 24546 C3 1 8 TO 10R F A3R65 0698 7188 8 RESISTOR 10 1 05W F TC 0 100 24546 C3 1 8 TO 10R F A3R66 0698 7259 4 1 RESISTOR 9 09K 1 05W F TC 0 100 24546 C3 1 8 T0 9091 F A3R67 0698 7236 7 RESISTOR 1K 1 05W F TC 0 100 24546 C3 1 8 T0 1001 F A3R68 0698 7209 4 1 RESISTOR 75 1 05W TC 0 100 24546 C3 1 8 TO 75R0 F A3R69 0698 7248 1 RESISTOR 3 16K 1 05W TC 0 100 24546 C3 1 8 T0 3161 F A3R70 0699 2234 T 1 RESISTOR 7 968K 1 125W TF TC 0 25 19701 5033R A3R71 0699 2235 8 2 RESI
80. Technical Writing Department 509 922 4001 or write Hewlett Packard Company Technical Writing Department 24001 E Mission TAF C 34 Spokane WA 99220 6 4 MECHANICAL AND CHASSIS PART LOCATIONS AND REFERENCE DESIGNATIONS Most mechanical parts are identified in Figures 6 1 to 6 6 These figures are located at the end of this section To find the part number and description of a mechanical part find the part in one of the drawings and then look up the item number in Table 6 3 mechanical part numbers are listed under Miscellaneous Parts toward the end of Table 6 3 6 2 rev 15FEB88 Model 8904A assembly attenuator isolator termination fan motor capacitor coupler diode diode thyristor varactor directional coupler delay line annunciator signaling device audible or visual lamp LED ampere alternating current accessory adjustment analog to digital audio frequency automatic frequency control automatic gain control aluminum automatic level amplitude modulation amplifier automatic phase control assembly auxiliary average American wire binary coded beryllium copper beat frequency oscillator binder head breakdown bandpass bandpass filter backware wave oscillator calibrate counter clockwise ceramic channel centimeter cabinet mount only coaxial Table 6 1 Reference Designations REFERENCE DESIGNATIONS miscellaneous electrical part hardware circula
81. The guard trace is at the same potential as the input signal at all times since it is connected to the output of U202 Potentially error producing leakage currents flow harmlessly to the guard trace 8 26 Principles of Operation A3 Model 8904A Service Low Pass Filters Service Sheet 2 Precise construction of the analog waveform from the DAC requires careful filtering Since the samples from the DAC are clocked through at approximately 1 67 MHz sampling theory dictates that a low pass filter of approximately 840 kHz or less is required in practice the 3 dB corner will be less than this but it must be greater than 600 kHz which is the upper frequency limit for a sine wave The output from the Track and Hold Circuit is filtered by the Sharp Cutoff Filter an elliptic function filter for sine waves noise and some types of complex waveforms when automatically selected The filter is flat within 0 01 dB to 600 kHz and has a 3 dB corner at 670 kHz Above 670 kHz the filter rolls off rapidly but ripples in the stopband Adjustments to the filter are made to keep the stopband attenuation more than 68 dB beyond 1 07 MHz For most other waveforms the Low Overshoot Filter a Gaussian type filter is automatically selected The filter prevents ringing but limits the useable frequency range to 50 kHz The Sharp Cutoff Filter is switched by relay K11 the Low Overshoot Filter by K10 The filters are switched in complement one or the other is alw
82. UF 10 100VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 10PF 5 100VDC CER 0 30 CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 33PF 5 100VDC CER 0 30 CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 15PF 5 100VDC CER 0 30 CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER NOT ASSIGNED CAPACITOR FXD 10UF 5 50VDC MET POLYC CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 2200PF 20 100VDC CER CAPACITOR FXD 4700PF 20 100VDC CER CAPACITOR FXD 1000PF 5 100VDC CER NOT ASSIGNED CAPACITOR FXD 6 8PF 5 200VDC CER NOT ASSIGNED CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD O1UF 10 100VDC CER CAPACITOR FXD 10PF 5 100VDC CER 04 30 NOT ASSIGNED CAPACITOR FXD 4 7PF SPF 100VDC CER CAPACITOR FXD 1UF 10 50VDC CER Mfr Code 20932 28480 28480 28480 28480 28480 28480 28480 Replaceable Parts Mfr Part Number 0160 4835 0160 4835 0160 4832 0160 4835 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4835 0160 4832 0160 4835 0160 4835 0160 4832 0160 4791 0160 4832 0160 4807 0160
83. a C or a G followed by an identifying number The controlled or gated input or output is labeled with the same number In this example 1 is controlled by G1 When a V input is active the output will be in its active state With the V input inactive the device functions as if the V input doesn t exist ENABLE When the EN input is active the output is enabled to function normally When the EN input is inactive the three state output this case becomes a high impedance effectively removing that device from the circuit TRANSMISSION X1 When the X1 input is active the associated input output pair are bi directionally connected together When X1 is inactive the connection is broken CONTROL When the controlled or gated input or output already has a functional label D is used here that labe will be prefixed by the identifying number 1D If the input or output is affected by more than one gate or control input then the identifying numbers of each gate or control input will appear separated by commas ADDRESS When GA is active the active address line 0 through 3 is the decoded value of the 1 and 2 binary inputs When the controlled address lines have a functional value that value will be prefixed by the identifying letter 8 14 Model 8904 Service PRINCIPLES OF OPERATION OVERALL What the Multifunction Synthesizer Can Do The HP 8904A Multifunction Synthesizer is a general purpo
84. ad at 1 MHz and 10 MHz equalization critical for stabilizing the amplifier Q20 is a common collector amplifier which drives common base amplifier Q21 to form the intermediate stage Q21 drives the collector of Q16 through Q17 which presents a high impedance load to Q21 and gives the intermediate stage high gain The output stage has unity gain The complimentary transistor pair Q18 and Q19 provide sufficient current to drive the load Q17 sets and thermally compensates the idle current in Q18 and Q19 Bias current for Q17 is generated by Q16 CR6 thermally compensates Q16 Sine X X Compensation Service Sheet 2 The Sine X X Compensation filter compensates the natural roll off of the sample generated waveforms up to 600 kHz L11 is adjusted for best flatness at 550 kHz The parasitic load capacitance is accounted for in the network s design 6 12 and 24 dB Attenuators Service Sheet 3 Three pi section attenuators provide 6 12 and 24 dB of programmable attenuation Each attenuator has an input impedance of 1 C232 and C504 introduce a load capacitance that is constant for all combinations of attenuation settings Principles of Operation A3 8 27 Service Model 8904 Floating Amplifier Driver and On Off Switch Service Sheet 3 The On Off Switch is opened for 15 ms when the Sharp Cutoff Filter is in and the frequency of the signal is changed to prevent the ringing in the filter from getting to the instrument s output
85. arts Description SEE SECTION 7 FOR FRONT PANEL RETROFIT KIT KEYBOARD ASSEMBLY NOT SEPARATELY REPLACEABLE DIGITAL ASSEMBLY NEW DIGITAL ASSEMBLY RESTORED DIGITAL ASSEMBLY NEW DIGITAL ASSEMBLY RESTORED BATTERY 2 8V 46A HR LUS DIOX PIN WASHER FL NM NO 000 04 IN ID 25 IN ID BATTERY 3V 1 2A HR LITHIUM POLYCARBON REFER TO SECTION 7 REFER TO SECTION 7 EPROM EPROM EPROM EPROM NO LONGER SEPARATELY REPLACEABLE Mfr Code 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 Factory Selected Component Refer to Section 5 Replaceable Parts Mfr Part Number 08904 60201 08904 60102 08904 69102 08904 60202 08904 69202 1420 0281 3050 0990 1420 0338 08904 87010 08904 87008 08904 87009 08904 87011 A Errata part change 6 5 Replaceable Parts Model 8904A Table 6 3 Replaceable Parts Reference HP Part nt Mfr Designation Number D Qty Description Code Mfr Part Number A3 2712A to 2942A A3 08904 60103 5 1 OUTPUT ASSEMBLY NEW 28480 08904 60103 A3 08904 69103 3 1 OUTPUT ASSEMBLY RESTORED 28480 08904 69103 2948A and above 08904 60203 6 1 OUTPUT ASSEMBLY NEW 28480 08904 60203 A3 08904 69203 4 1 OUTPUT ASSEMBLY RESTORED 28480 08904 69203 1 NOT ASSIGNED A3C2 0180 0116 1 11 CAPACITOR FXD 6 8UF 10 35VDC 56289 1500685 903582 0160 4832 4 35 CAPACITOR FXD O1UF 10 100VDC CER 28480 0160 4832
86. as sinewaves a sharp cutoff filter is selected its 3 dB corner is approximately 670 kHz For waveforms less smooth such as triangle waves or tone bursts a low overshoot filter is selected with a 3 dB corner of 230 kHz The Audio Amplifier has 19 dB gain and passes signals up to 600 kHz with good flatness and low distortion Attenuator 1 can be programmed for 0 6 12 or 24 dB attenuation It reduces the need for large level range control in the DWSIC and thereby maintains waveform fidelity at low levels The Floating Output Amplifier is a single ended to differential converter with a gain of 1 12 In its float mode either the high or the low output not shown in the block diagram can be floated up to 10 V while the signal from the instrument itself appears on the other output Output impedance is 500 Attenuator 2 can be programmed for 0 or 48 dB Both the high and low outputs are protected from inadvertent application of a large reverse voltage by the Overvoltage Detector and Relay When a large output voltage is sensed the Overvoltage Detector opens the relay The relay is reset by the instrument s controller when any key is pressed if the overvoltage condition has been removed If the instrument has Option 006 balanced output Output 1 is floated by means of a balancing transformer not shown in figure 8 7 The transformer provides a true balanced 600 output but limits the useable frequency range and fidelity of the various non sinusoi
87. at is smooth the transitions between samples from the DAC amplifiers to boost the maximum output and attenuators to increase the outputs dynamic range Figure 8 1 is a conceptual block diagram of the simplest configuration of the instrument one without Options 001 002 or 003 The blocks indicate conceptually how th data is handled Principles of Operation Overall 8 15 Service Model 8904A OUTPUTS CHANNEL A OUTPUT 1 FREQUENCY Figure 8 1 Conceptual Block Diagram of a Standard Instrument The standard instrument has only one channel Channel A Channel A can output one of the six available waveforms Four of the waveforms sine sawtooth triangle and square are periodic and thus have a frequency and phase which can be controlled The level of all waveforms can be controlled Level is controlled in both the DWSIC and the analog output circuits The DWSIC DWSIC in response to front panel or HP IB inputs directed to the instrument s internal computer generates the basic waveforms in their digital form for each channel modulates and combines them still in digital form as requested and delivers them to the appropriate digital to analog converter Figure 8 2 shows a one channel portion of the DWSIC The diagram is highly simplified but detailed enough to illustrate general concepts such as e generation of a basic sine wave e setting and modulating its phase e setting and modulating its frequenc
88. axial cable in the instrument by cutting it with the diagonal cutters being careful not to score the soft insulation on the cables 3 Remove the necessary plastic hole plugs in the rear panel by approaching them from inside the chassis with the needle nose pliers and squeezing in the small holding tangs on opposite sides of the plug Grasp the front of the plug with your fingers to pull it away from the panel Do not attempt to pry the plug out from the panel or the panel surface may get scarred rev 15DEC89 Front to Rear Panel Output Conversion 7 3 Instrument Changes Model 8904A Cable Routing 1 Refer to figures 7 1 7 2 and 7 3 Remove the BNC connector ends from the front panel one at a time and insert them into the corresponding openings in the rear panel 2 After all of the connectors have been transferred to the rear panel secure the cables to the side rail as shown in figure 7 3 using the new cable ties 3 Install one new lock washer and one new nut on each connector 4 Tighten the nuts on the BNC connectors hand tight using the nut driver The holes in the panel are D shaped and therefore prevent the connector from turning without having to tighten the nuts excessively 5 Verify that the SMC connections on the A3 Output Assembly and if the instrument has Option 002 the 10 Output Assembly are tight Final Steps 1 Insert the new plastic hole plugs into the front panel output openings by carefully working the plugs int
89. ays in The filter control signal on line FLC is inverted by peripheral driver U8A which controls K10 The output of U8A is inverted by U8B which controls K11 A high on FLC switches in the Low Overshoot Filter The filters can be isolated and tested manually by connecting a signal source to J5 and moving jumper J3 to connect point 2 to point 3 and by connecting a signal analyzer to J6 and moving jumper J7 to connect point 2 to point 3 Audio Amplifier Service Sheet 2 The Audio Amplifier has a precise gain of 8 9 19 dB It must pass signals from dc to 600 kHz and maximum levels of 8 9 Vpk with minimum introduction of ripple distortion noise or dc offset The amplifier is a discrete design of a standard inverting operational amplifier The gain is the ratio of the parallel combination of R48 and R231 to R47 The Audio Amplifier has three stages 1 an input stage U9 Q14 and Q15 2 an intermediate high gain stage Q20 and Q21 and 3 an output driver stage Q18 and Q19 The virtual ground of the amplifier is the junction of C40 and R49 In the input stage the ac component of the input signal flows through C40 and R56 into the base of Q14 DC current flows through R49 and is amplified and inverted by U9 U9 functions as an integrator providing large gain for dc and low gain for ac The output of U9 is fed into the emitter of Q14 through R53 Q14 differentially sums the ac and dc signals Components C45 C46 and R57 form a lag le
90. bilities is illustrated in Figure 8 6 Figure 8 6 also shows a second output channel which is included as Option 002 If Option 002 is added without Option 001 any of the six basic waveforms can be generated at the second output independent of the first output but neither output can be modulated or summed Principles of Operation Overall 8 19 Service Model 8904A OUTPUTS OUTPUT 1 e 221 9 lt SUM QUTPUT 2 SUM ped PHASE PHASE PHASE FREQUENCY FREQUENCY FREQUENCY CHANNEL B CHANNEL CHANNEL D Figure 8 6 Conceptual Block Diagram of an Instrument with Options 001 and 002 8 20 Principles of Operation Overall Model 8904A Service FLOATING SAMPLER LOW PASS AUDIO OUTPUT OVERVOLTAGE SAMPLER AMPLIFER FILTER AMPLIFER ATTEN 1 AMPLIFER ATTEN 2 OUTPUTS RELAY OVERVOL TAGE DETECTOR Figure 8 7 Analog Output Block Diagram Analog Waveform Processing The analog waveform processing block diagram is shown in figure 8 7 Instruments with Option 002 have a second identical output assembly The DAC receives digital inputs from the instrument s controller and converts them to an analog voltage Because the DAC output has significant switching transients each new output is sampled after settling The Sampler Amplifier buffers the output of the Sampler The Low Pass Filter is needed to accurately construct the sample generated waveform For smooth waveforms such
91. can be retrofit with this option If the instrament has Option 004 front panel connectors moved to rear panel the rear panel connectors will need to be moved to the front panel rev 15DEC89 7 1 Instrument Changes Model 8904A To retrofit Option 006 balance output order HP 11837A from your local Hewlett Packard Sales office Only instruments with serial prefix 2948A and above can be retrofit with this option The added balanced output will replace one of the outputs already in the instrument if it has Option 002 second internal synthesizer and output If the instrument has Option 004 front panel connectors moved to rear panel the rear panel connectors will need to be moved to the front panel 7 3 INSTRUMENT MODIFICATIONS Instrument modifications include firmware updates and hardware modifications For information on firmware updates refer to the following table and to the section titled Firmware Updates Serial Prefix Firmware History 2732A and below 20987A The first two editions of firmware had several problems and were incomplete and though useable It is recommended that all instruments be upgraded to 22987A Revision 22987A with HP 08904 87010 A2U12 2 to 2942A 22987A Problems noted in the previous firmware revision were fixed However the following problem has been noted When used with HP IB controllers which process HP IB commands very fast the instrument may hang up the HP IB when the instrument is a tal
92. ceable Parts Figure 6 4 Rear Panel Assembly Option 005 2948A and above rev 30NOV89 6 26 1 Model 8904A Replaceable Parts LABEL LOCATION SERIAL PREFIX 2822A ANO ABOVE SEE SECTION 7 99 Figure 6 5 Covers Labels and ROMs rev 25SEP88 6 27 Replaceable Parts Model 8904 OPTIONAL DUAL REAR OUTPUTS REAR OUTPUT 2 lt z o STANDARD OUTPUT OPTION 002 Figure 6 6 Output Cables 1 of 2 6 28 89 Replaceable Parts Model 8904A Figure 6 6 Output Cables Option 005 2948A and above 2 of 2 6 29 rev 30NOV89 HP8904A Table of Contents TABLE OF CONTENTS Section 7 Instrument Changes Introduction to This Section 7 1 Option Conversions X sal sou doy Qoo lw or E o ete rw eB 7 1 Instrument Modifications 7 2 Front To Rear Panel Output 7 3 Descriptions coute fF ese HbA VOR IER EOS Eod d e 7 3 Parts Required eee e eS Wy eut dc d e e ee Sel 7 3 Tools Required 4 ELSE BS we 7 3 Modification Procedure 7 3 Operation Verification v ee 7 4 Rear To Front Panel Output
93. ck the cable which terminates at A2J11 Connect a short BNC cable between the rear panel RESET OUTPUT and RESET INPUT Connect the oscilloscope input or a logic probe to A2U30 pin 12 Key in SHIFT RESET several times as was done in step 6 and observe the oscilloscope or the logic probe The logic probe should blink a high each time The oscilloscope should trigger a sweep each time If faulty check the cable which terminates at A2J12 Troubleshooting Phase Synchronization 8 42 1 Model 8904A Service HOW TO RESTORE THE SERIAL NUMBER IN A REPLACEMENT A2 DIGITAL ASSEMBLY Description If the A2 Digital Assembly has been replaced by a new or exchange assembly the instrument s serial number suffix will need to be entered into non volatile memory RAM The suffix is the last five digits of the serial number For example the suffix of serial number 1234A56789 is 56789 The serial suffix can be entered from the front panel keyboard by the following procedure Note however that the procedure will only work for an assembly coming from a Hewlett Packard sales office or service center If the instrument has lost the contents of its non volatile memory for example if the backup battery fails the serial number cannot be entered the A2 Digital Assembly must first be replaced then the serial number can be entered The procedure is written with simple steps followed by detailed notes Normally it is only necessary to fo
94. dal waveforms Interrelationship of the Circuit Assemblies Figure 8 8 and figure 8 8 1 diagrams the assemblies by assembly number and shows their interrela tionship rev 15DEC89 Principles of Operation Overall 8 21 Service Model 8904A HP 8904 MULTIFUNCTION SYNTHESIZER Gu 10 MHz REF OUT is DISPLAY DIGITAL ASSY PORT COMPUTER OUTPUTS OUTPUT Al ASSY KEYBOARD ASSY 10 OUTPUT ASSY COPT 0022 4 POWER SUPPLY ASSY Figure 8 8 Interrelationship of Instrument Assemblies Serial prefix 2942A and below 8 22 Principles of Operation Overall rev 1ISDEC89 Model 8904A Service 8904 MULTIFUNCTION SYNTHESIZER 10 MHz EXT REF IN CLOCK INPUT SYNC f OPT 005 OUTPUT 0 eser INPUT 1 005 NOUTPUT 4 A2 DIGITAL ASSY E 10 MHz REF OUT DIGITAL PORT COMPUTER OUTPUT ASSY OUTPUTS OUTPUT ASSY OPT 002 Figure 8 8 1 Interrelationship of Instrument Assemblies Serial prefix 2948A and above rev 15DEC89 Principles of Operation Overall 8 22 1 Model 8904A Service A2 DIGITAL ASSEMBLY General The A2 Digital Assembly creates the output waveforms as a series of digital codes via its DWSIC and performs the overall control and functioning of the instrument via its microprocessor Specific tasks include contro the instrument s general operation create the digital waveforms distribut
95. dangerous Intentional interruption is prohibited Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an auto transformer for voltage reduction make sure the common terminal is connected to the earth terminal of the power source If this product is not used as specified the protection provided by the equipment could be impaired This product must be used in a normal condition in which all means for protection are intact only No operator serviceable parts in this product Refer servicing to qualified personnel To prevent electrical shock do not remove covers Servicing instructions are for use by qualified personnel only To avoid electrical shock do not perform any servicing unless you are qualified to do so The opening of covers or removal of parts is likely to expose dangerous voltages Disconnect the product from all voltage sources while it is being opened The power cord is connected to internal capacitors that my remain live for 5 seconds after disconnecting the plug from its power supply For Continued protection against fire hazard replace the line fuse s only with 250 V fuse s or the same current rating and type for example normal blow or time delay Do not use repaired fuses or short circuited fuseholders Always use the three prong ac power cord supplied with this pr
96. e 6 2 lists abbreviations used in the parts list and on schematics 6 3 REPLACEABLE PARTS LIST Table 6 3 is a list of replaceable parts and is organized as follows a Electrical assemblies and their components with reference designations in alphanumeric order b Chassis mounted parts with reference designations in alphanumeric order c Mechanical parts with reference designations in numeric order Ordering Parts Instrument Serial Numbers Attached to the rear of the instrument is a serial number plate The first four digits and the letter are the instrument serial number prefix The last five digits serial number suffix are unique to each instrument When parts in the instrument are changed the serial number prefix of the instrument may also change This means that sometimes a part will be listed more than once in the the replaceable parts list along with a serial number prefix or range of serial number prefixes Find the serial number prefix on the serial plate of your instrument and order the part listed under the corresponding prefix in the table If no serial prefix information is listed the part is compatible in instruments of all serial numbers NOTE It is possible that some assemblies in your instrument have been updated through service or retrofitting to reflect changes made to instruments with serial number prefixes later than that shown on your instrument serial number tag Be sure to note the printed circuit board numb
97. e new ground wire If it does strip 8 mm 5 16 inch of insulation from it and properly wrap and solder it to a second new lug Replace the screw in the standoff inserting the screw through the lug with the black wire first and then through the lug with the new ground wire Tighten the screw Put the main wiring harness next to the standoff and secure both together with a gray cable tie HP 1400 0249 Cut off the excess tie wrap lead Make sure the box on the tie wrap is toward the inside of the instrument Replace the top cover and make a quick check of the operation of the instrument 7 8 MODIFICATION FOR OUTPUT OVERVOLTAGE PROTECTION IMPROVEMENT Serial Prefix 2747A and below The output overvoltage protection circuit of the HP 8904A Multifunction Synthesizer has a potential problem On instruments with serial prefix 2747A and below excessive leakage in four clamp diodes 15 to A3CR418 shifts the trip point of the circuit to a voltage too high to protect the output against inadvertent application of high reverse voltage No failures due to this problem have been observed but all instruments with serial prefix 2747A and below should be modified Modify the instruments as directed below Refer to Service Sheet SS4 for schematic and component locator 1 rev 15DEC89 Order the parts listed in the table below 2 Replace diodes ASCR15 through 18 with part number 1901 0880 3 Replace A3R494 and A3R95 17
98. e that inputs to the Frequency Adder are constants so that the P input of the Phase Accumulator is a four bit constant P The Frequency Adder will be discussed later P can theoretically take on values between 0 and 24 1 or 15 in decimal This constant represents a fixed frequency as will be seen shortly Each clock period the Latch outputs the sum of the input and the output of the Phase Accumulator of the previous clock period For example if P 1 and the Latch output for the last clock period was 6 the Phase Accumulator outputs 6 1 7 on the next clock period 7 1 8 on the next and so forth until the output reaches 15 1 At this time the output goes to 0 since Phase Accumulator discards carries From 0 the Phase Accumulator increments once each clock period 8 3 illustrates the resulting staircase and also shows what happens when P 2 and 3 Figure 8 3 The Output of the Phase Accumulator for P 1 2 and 3 Principles of Operation Overall 8 17 Service 8 18 Model 8904 is an interesting case The count sequence in decimal is 0 3 6 9 12 15 2 5 8 11 14 1 4 7 10 13 0 etc The Latch outputs three uneven staircases that repeat every 16 clock periods In general if P is not 0 but is small compared to the number of possible states 16 in the current example the Latch outputs a series of staircases sometimes uneven with a frequency equal to the Clock frequency x P 16 Adding Phase Shift F
99. e waveform data to the proper output control the programmable analog circuits attenuators filters etc retain instrument settings in RAM backup RAM at power down process keyboard HP IB digital port and overvoltage interrupts scan the keyboard when a key press is detected interface with HP IB generate the reference clocks switch between internal and external references control the beeper generate and time the display backlight control the front panel displays and annunciators output waveform data to the digital port Because some circuits on the assembly are proprietary and because the assembly is available as an exchange assembly a schematic diagram with detailed theory and troubleshooting has not been provided Troubleshooting procedures to isolate a fault to the assembly can be found in the troubleshooting section of this manual Principles of Operation A2 8 23 Service 8 24 Model 8904A A3 OUTPUT ASSEMBLY Service Sheets 1 through 4 General The Output Assembly converts the digitally encoded waveform from the digital waveform synthesis integrated circuit DWSIC on the A2 Digital Assembly to a precise and useable analog signal Instruments with Option 002 have a second Output Assembly designated 10 which is identical to For troubleshooting purposes the two Output Assemblies can be interchanged or compared node for node Specifically the Output Assembly contains the digital to analog converte
100. en the A2 Digital Assembly and one of the other assemblies The A3 or A10 Output Assembly can be troubleshot to the component level using the troubleshooting information on the schematic diagrams NOTE If the A2 Digital Assembly is replaced it will be necessary to restore the instrument s serial number and where applicable Option 001 and or 003 in non volitile memory The procedures to do this follow the last troubleshooting procedure The the troubleshooting procedures verify the signals in the A2 Digital Assembly to A3 or A10 Output Assembly Interface A2 Digital Assembly to Al Keyboard Assembly Interface A2 Digital Assembly to A5 Display Assembly Interface or 10 Output Assembly A6 High Power Output Other procedures include e Howto Restore the Serial Number in a Replacement A2 Digital Assembly e How to Restore Options 001 and 003 in a Replacement A2 Digital Assembly e How to Replace the Memory Backup Battery NOTE If the instrument has Option 002 a second output and the fault appears only on one output swap the A3 and A10 assemblies and see if the fault tracks the output assembly If it does then the Output Assembly is at fault otherwise the A2 Digital Assembly or possibly an interconnection is at fault rev 15DEC89 Troubleshooting General 8 29 Service Model 8904A A2 DIGITAL ASSEMBLY TO A3 OR A10 OUTPUT ASSEMBLY INTERFACE Description The following procedure will help identify whether an
101. enerate an error message on the instrument s display CR415 through CR418 protect the comparators VR31 shifts the comparators outputs to a TTL level C440 and C441 prevent arcing of the contacts of K402 when the relay is deactivating C64 CR17 CR18 and R122 open K402 at instrument turn on Components C409 through C413 and L402 prevent high frequency parasitic signals on the high output line from radiating from the instrument Relay K404A controls the float or ground state of the low output line 8 28 Principles of Operation A3 Model 8904A Service TROUBLESHOOTING GENERAL The goal of the following troubleshooting procedures is to isolate the fault to a single replaceable assembly The instrument assemblies are as follows Al Keyboard A2 Digital A3 Output A4 Power Supply 5 Display High Power Output Installed only in Option 006 10 Output Installed only in Option 002 The exploded drawings at the end of section 6 in the manual will assist in locating disassembling and reassembling these assemblies The troubleshooting procedures assume the failure is catastrophic For subtle or slightly out of specification failures it is best to begin diagnosis by running the performance tests and adjustments To isolate the fault to a printed circuit board assembly it is usually necessary to check only the signals on the interface interconnections between assemblies Specifically this will be the interface betwe
102. er must be responsible for individual state and country regulations for battery disposal Do not unplug any boards in the Multifunction Synthesizer unless the instrument is unplugged or switched to STBY standby Some boards contain devices which can be damaged if the board is removed when the power ts on Use conductive foam when removing MOS devices from sockets Use care when unplugging ICs from high grip sockets rev 15DEC89 Model 8904A Service 8 4 SERVICE TOOLS HELPS AND INFORMATION Printed Circuit Board Extractor A Printed Circuit Board Extractor HP 08904 00012 is supplied as part of this manual It eases removal of the A3 and 10 Output Assemblies It hooks under the board or the metal board shield so the board can be pulled off the mounting studs Assembly Parts and Cable Locations The exploded view drawings at the end of Section 6 will assist in locating circuit board assemblies cables and mechanical hardware For the A3 and 10 assemblies only the locations of individual components mounted on printed circuit boards are shown adjacent to the schematic diagram on the appropriate service sheet The part reference designator is the assembly designator plus the part designator For example A3R9 is resistor R9 on the A3 assembly For specific component descriptions and ordering information refer to Table 6 3 Replaceable Parts in Section 6 Mechanical chassis parts have reference designators with no prefix lette
103. er of the assembly being repaired or replaced when ordering parts for your instrument Replaceable Parts Model 8904A How to Order To order a part in the Replaceable Parts List call or write the nearest Hewlett Packard Sales Office Have the following information ready to speed the ordering process 1 The Hewlett Packard part number with the check digit The check digit will ensure accurate and timely processing of your order 2 The quantity required 3 An approved purchase order number Sometimes required NOTE Within the USA it is better to order directly from the HP Support Materials Organization Roseville California Ask your nearest HP office for information and forms for the Direct Order System Replaceable Parts List Updating Manual Updates A MANUAL UPDATES packet is shipped with the manual when necessary to provide the most current information available at the time of shipment These packets consist of replacement and addition pages which should be incorporated into the manual to bring it up to date Hewlett Packard offers a Documentation Update Service that will provide you with further updates as they become available If you operate or service instruments of different serial prefixes we strongly recommend that you join this service immediately to ensure that you manual is kept current For more information refer to the Documentation Update Service reply card included in this manual or call
104. ered the backspace key can be used to back up to the digit in error If the serial suffix is correct press SHIFT f2 If the serial suffix is incorrect press f3 and key the correct number CAUTION This is your last opportunity to check the serial suffix before it is entered permanently into the instrument It cannot be changed once it has been entered The display should now read something like the following The example shows serial suffix 56789 Serial Number Installation Serial Number S N 56789 installed After the 10 second timeout the display will read HP 8904A Main Selection Level 1 Channel Config Press SHIFT PRESET Confirm that the serial suffix has been invoked The display will look something like the following The example shows serial suffix 56789 HP 8904A Opts 02 Firmware Revision 18387A Serial No 56789 If the instrument has Options 001 and or 003 these options can be restored after restoring the serial number Refer to the procedure following this one Troubleshooting Serial Numbers 8 45 Service 8 46 Model 8904A HOW TO RESTORE OPTIONS 001 003 AND 005 IN A REPLACEMENT A2 DIGITAL ASSEMBLY Description If the A2 Digital Assembly has been replaced by a new or exchange assembly the instrument s serial number suffix will need to be entered into non volatile memory RAM Restoration of the serial number is documented in the previous
105. erference traveling wave tube micro 1075 used in parts list microfarad used in parts list ultrahigh frequency unregulated voltampere voltage controlled oscillator volts dc working used in parts list volts filtered variable frequency oscillator very high frequency volts peak volts peak to peak volts rms voltage standing wave ratio voltage tune oscillator vacuum tube volts switched working inverse wirewound without yttrium iron garnet characteristic impedance NOTE All abbreviations in the parts list will be in upper case MULTIPLIERS Abbreviation Prefix Multiple tera 1012 109 105 kilo 103 10 deci 10 1 centi 1072 milli 1073 1076 nano 10 3 pico 10 12 femto 10 15 atto 10718 ost Zoar ZONH 6 4 Model 8904 Reference Designation 1 2712A to 2917A 11 2923A and above Al wi A2 2712 to 2942A A2 A2 2948A and above 2 2 2712A to 2942A A2BT1 2712A to 2942A A2BTI 2712A to 2732A 20121 A2U131 2737A to 2942A A2U12 2013 2737 2940 2012 2742A and above 2012 2737A and above A2U13 HP Part Number 08904 60201 08904 60102 08904 69102 08904 60202 08904 69202 1420 0281 3050 0990 1420 0338 08904 87010 08904 87008 08904 87009 08904 87011 gt Qty 1Refer to Section 7 for update information rev O1JUL91 Table 6 3 Replaceable P
106. est operation Value shown is average or most commonly selected value Model 8904A Service Table 8 1 Schematic Diagram Notes 2 of 11 Values for all components are marked in units of farads henries and ohms unless otherwise specified Asterisk denotes a factory selected value Value shown is typical See Section V Tool aided adjustment Encloses front panel designation Encloses rear panel designation Circuit assembly borderline Other assembly borderline Heavy line with arrows indicates path and direction of main signal Heavy dashed line with arrows indicates path and direction of main feedback Indicates stripline RF transmission line above ground Wiper moves toward cw with clockwise rotation of control as viewed from shaft or knob Numbered Test Point measurement aid provided Encloses wire or cable color code Code used is the same as the resistor color code First number identifies the base color second number identifies the wider stripe and the third number identifies the narrower stripe e g denotes white base yellow wide stripe violet narrow stripe A direct conducting connection to earth or a conducting connection to a structure that has a similar function e g the frame of an air sea or land vehicle A conducting connection to a chassis or frame Common connections All like designation points are connected Letter off page connection Number Service Sheet number
107. h an AND relationship to those inputs or outputs labeled with the same identifier The m is replaced with a number or letter the identifier OR Dependency Binary affecting input with an OR relationship to those inputs or outputs labeled with the same identifier The m is replaced with a number or the letter the identifier Address Dependency Binary affecting inputs of affected outputs The m prefix is replaced with a number that differentiates between several address inputs indicates dependency or indicates demultiplexing of address inputs and outputs The m suffix indicates the number of cells that can be addressed Enable Dependency Binary affecting input which when active enables all outputs When inactive open collector and open emitter outputs are off and three state out puts are at an external high impedance state When the enable input affects only certain inputs and outputs they will be numbered to indicate the logic connection Transmission Dependency Binary affecting input which bidirectionally connects de pendent inputs and outputs Mode Dependency Binary affecting input used to indicate that the effects of partic ular inputs and outputs of an element depend on the mode in which the element is operating The m is replaced with a number or letter the identifier Interconnection Dependency Indicates the existence of internal logic connections between inputs outputs internal inputs and or internal outpu
108. he hold period responds quickly and stably to a wide variety of inputs has no dc offset and can drive the load at its output The amplifier can be divided into two main stages 1 a slower high gain input stage U203 and associated parts and 2 a fast lower gain output stage Q210 and following The input stage assures sufficient gain accuracy the output stage assures quick response and output drive For high frequency signal components capacitor C201 bypasses the input stage so that the input signal appears at the gate of FET Q210 A high input impedance is maintained because capacitors C226 and C225 short resistors R216 and R218 respectively to the output of the output stage which is a unity gain follower Both ends of R216 and R218 move in step with the input so no current flows through them Capacitor C217 prevents high frequency components from entering U203 Capacitor C224 reduces the high frequency stage gain to unity to eliminate its influence For low frequency components the input signal appears at the non inverting input of U203 The high open loop gain of U203 and the unity feedback force the inverting input 0203 to precisely follow the non inverting input Refer now to Service Sheet 1 The guard traces associated with U203 prevent any significant leakage of current from nearby circuit nodes of different potential on to highly sensitive nodes such as C219 Leakage is most severe when the humidity is high
109. he SMC connections on the A3 Output Assembly and if the instrument has Option 002 the 10 Output Assembly are tight Final Steps 1 2 3 Insert the new plastic hole plugs into the rear panel output openings by carefully working the plugs into the holes with your fingers The plugs fit tightly and will require some pressure to get them started in the holes Replace the bottom cover by reversing the removal procedure Remove the Option 004 label from the rear panel Operation Verification 1 2 Connect the power cord and turn the instrument on The instrument should beep immediately upon power up and then again about 4 5 seconds later The display should read HP 8904A Main Selection Level f1 Channel Config Key in the following keys This will set up 5 dc on the OUTPUTS 1 HIGH connector and ground the LOW connector f1 Channel Config NEXT SHIFT FLOAT 1 OFF WAVE FORM AMPTD 5 V Connect a DC voltmeter set to measure a 5 V dc signal to the OUTPUTS 1 HIGH connector The voltmeter should read approximately 5 dc If the instrument is equipped with a second output Option 002 key in NEXT SHIFT FLOAT 2 OFF WAVE FORM AMPTD 5 V Connect the DC voltmeter to the OUTPUTS 2 HIGH connector The voltmeter should read approximately 5 V dc Perform the AC and DC Amplitude Accuracy Test and the AC Amplitude Flatness Test Refer to the HP 8904A Operation and Calibration Manual
110. he instrument presets momentarily short pin 10 of U2 to ground The instrument should beep and the display should read For A3 Reverse Power Relay Tripped on Output 1 Press any key to reset and continue For 10 Reverse Power Relay Tripped on Output 2 Press any key to reset and continue 8 36 Troubleshooting Digital Output Interface Model 8904A Service Table 8 2 and A10 Interconnections to A2 A ic Pm Pm Pin Clocks IC Pin ic A10 Miscellaneous Control JiandJ6 2 m ie Overvoltage Control 10 J6 e Control J1 J5 us 12 17 U38 19 11 18 U24 15 IC Pin Pn IC U2 12 17 U35 19 U2 11 18 U24 15 Troubleshooting Digital Output Interface 8 37 Service Model 8904A A2 DIGITAL ASSEMBLY TO A1 KEYBOARD ASSEMBLY INTERFACE Description The following procedure will help identify whether a keyboard failure is due to the keyboard itself or the controller It does this by checking signals on the interface between the two assemblies If the tests pass but the instrument does not respond to keyboard inputs the A2 Digital Assembly should be replaced If the tests fail trace the signal to the Al Keyboard Assembly Retest the line that was faulty to determine whether the fault is in A2 or its interconnection to Al Refer to Table 8 3
111. ial purchase In the HP 8904A Multifunction Synthesizer this can be done as indicated in the following table Option Retrofitability for Instrument Serial Prefix Range Number 2942A and below 2948A and above Yes 001 002 Yes 003 Yes 004 Yes except in combination with Option 005 or 006 Delete 004 Yes 005 Yes except in combination with Option 004 006 Yes except in combination with Option 004 To retrofit Option 001 three internal channels channel A modulation summation and sequence capability order HP 11816A from your local Hewlett Packard Sales office To retrofit Option 002 second internal synthesizer and output order HP 11817A from your local Hewlett Packard Sales office To retrofit Option 003 fast hop and digital modulation capability order HP 11818A from your local Hewlett Packard Sales office To retrofit Option 004 front panel connectors moved to rear panel follow the instructions in section titled Front to Rear Panel Output Conversion This option cannot be added in combination with Option 005 multi instrument phase synchronization or 006 balance output To delete Option 004 rear panel connectors moved to front panel follow the instructions in the section titled Rear to Front Panel Output Conversion To retrofit Option 005 multi instrument phase synchronization order HP 11827A from your local Hewlett Packard Sales office Only instruments with serial prefix 2948A and above
112. instrument failure is due to the analog output circuits or their control inputs Since the layout of the instrument board assemblies breaks the circuit assemblies along digital analog lines this procedure will also help determine which assembly the A2 Digital Assembly or the or 10 Output Assembly is at fault It does this by checking signals on the interface between the two assemblies If the tests pass but the output is faulty the A3 10 assembly should be replaced If the tests fail trace the signal to the A2 assembly Retest the line that was faulty to determine whether the fault is in or its interconnection to Refer to Table 8 2 and 10 Interconnections to A2 at the end of this procedure for a cross reference of the signal interconnections Equipment Counters Lan HP 5315B Digital Multimeter phan ce EU dae oe HP 3478A Oscilloscope 2 SS Me eas HP 1740A or Tektronix 2235 Procedure 1 Preliminary Setup a If the instrument has Option 002 a second output assembly A10 and Output 1 the output from the A3 Output Assembly is to be checked move the 10 Output Assembly out of the way Refer to Figure 8 11 How to Access A3 in Instruments Equipped with Option 002 b Check that switches 1 and 2 of the Service Switch 51 on the A2 Digital Assembly are open switches 3 through 10 are clo
113. ization Option 005 8 421 How Restore the Serial Number In Replacement 2 Digital Assembly 8 43 How To Restore Options 001 003 and 005 In A Replacement 2 Digital Assembly 8 46 How Replace the Memory Backup 8 48 1 Service Sheet 1 Output 8 51 Service Sheet 2 Output Assembly 8 53 Service Sheet 3 Output 8 53 Service Sheet 4 Output 8 55 Service Sheet 5 High Power Output Assembly 8 57 Model 8904A Service Section 8 SERVICE 8 1 INTRODUCTION TO THIS SECTION This section contains information for troubleshooting and repairing the Multifunction Synthesizer Included are principles of operation troubleshooting checks and schematic diagrams for selected circuits 8 2 HOW THE SECTION IS ORGANIZED Section 8 contains the following Safety Considerations Service Tools Helps and Information Schematic Symbology and Diagram Notes Principles of Operation Troubleshooting Selected Schematic Diagrams and Component Locators Foldouts 551 through 554 8 3 SAFETY CONSIDERATIONS Before Applying Power Verify that the instrument is set to match
114. k Assembly Top 2923A and above 6 22 4 rev 01 NOV89 Model 8904A Replaceable Parts ITEM 89 LEAVING SCREWS z u aii lt z S ne N gt DETAIL SWITCH MOUNTING Figure 6 1 Main Deck Assembly Top Option 005 2948A and above rev 30NOV89 6 23 Replaceable Parts Model 8904A OPTIONAL OUTPUTS gt 8 2 a lt lt Figure 6 2 Deck Assembly Bottom 6 24 rev 3ONOV83 Model 8904A Replaceable Parts Figure 6 2 Main Deck Assembly Bottom Option 006 2948A and above 9 6 24 1 Replaceable Parts Model 8904A SEE DETAIL A1 At os St 0566 DETAIL A1 052 o z 5 2 gt Figure 6 3 Front Panel Assembly 2712A to 99174 See Section 7 for Front Panel Retrofit Kit 6 24 2 rev 30NOV89 Model 8904 Replaceable Parts SEE DETAIL 1 DETAIL 1 LE n o LT 2 n gt Figure 6 3 Front Panel Assembly 2923A and above rev 30NOV89 6 24 3 Model 8904A Replaceable Parts SEE DETAIL 1 DETAIL A1 o z Q HL gt Figure 6 3 Front Panel Assembly Option 006 2948A and above 89 6 25 Replaceable Parts Model 8904A OUTPUT OPTIONS Figure 6 4 Rear Panel Assembly 6 26 rev 30NOV89 Model 8904A Repla
115. ker This problem can be corrected by upgrading to Revision 22987A with HP 08904 87010 as 2012 2948A and above 27887A Problems noted in the previous firmware revisions were fixed Programs for operating Options 005 and 006 were added Two enhancements were added to Option 001 Hop RAM sequencing and FM stereo A physical re design of the controller was made which does not permit this added firmware to be retrofitted into older instruments Two revisions of firmware share the same revision code 22987A The older revision has part number 08904 87007 for ROM 2012 the newer revision has part number HP 08904 87010 For information on recommended hardware modifications refer to the following table and to the section titled Hardware Modifications Serial Prefix Nature of Modification 2737 and below 274 and below 2817A and below 2917A and below Modification for possible ground wire shock hazard Modification for output overvoitage protection improvement Modification for potential power supply short Modification for front panel assembly 7 2 rev 15DEC89 Model 8904A Instrument Changes 7 4 FRONT TO REAR PANEL OUTPUT CONVERSION Description This procedure describes how to convert an instrument with front panel output connectors that is a standard instrument to one with rear panel connectors that is Option 004 The procedure applies to instruments with one pair of outputs or two that is
116. l cause the cover to push away from the frame Refer to figure 7 4 Locate the ground wire It has green insulation with a yellow stripe and is inside the rear panel in the right rear corner of the instrument beneath the red and silver warning label Carefully slit the black shrink tubing over the ground wire connection to the line socket A sharp X acto knife is recommended The shrink tubing will not be replaced Inspect the soldered wire connection on both ends of the ground wire and compare the wire wrapping to figure 7 5 One end of the wire goes to the chassis ground lug and the other end to the socket ground connection on the rear panel line socket If the solder joints are properly wrapped and soldered replace the top cover and make a quick check of the operation of the instrument WARNING LABEL STANDOFF SCREW BLACK WIRE GREEN YELLOW GROUND WIRE GRAY CABLE TIE STANDOFF MAIN HARNESS GRAY Figure 7 4 Parts Location Shown with Power Supply Removed Firmware Updates Hardware Modifications 7 11 Instrument Changes Model 8904A GOOD WRAPPING Wire is mechanically secure prior to soldering The wire wrap is at least three quarters to one full turn POOR WRAPPING 1 Wire is not mechanically secure prior to soldering 2 Wrap is less than three quarters turn 3 Wrap exceeds one full tum 1 and 2 1 and 2 Figure 7 5 Ground Wire Wrapping Replacing the Ground Wire
117. llow the simple steps and ignore the notes Refer to the notes when a step doesn t work quite right NOTE If the instrument has Option 001 003 and or 005 these options can be restored after restoring the serial number Refer to the procedure following this one Procedure 1 Switch LINE to OFF and then back to ON After the instrument powers up the display should read HP 8904A Main Selection Level 1 Channel Config NOTE After about 3 minutes if no key has been pressed the backlighting on the display will go off This is normal When another key is pressed the backlighting will go back on 2 Press SHIFT PRESET The display will look something like the following then after about 3 seconds it will time out The example shows an instrument with Option 002 installed Check that the serial suffix is 00000 HP 8904A Opts 02 Firmware Revision 18387A Serial No 00000 rev 15DEC89 Troubleshooting Serial Numbers 8 43 Service 8 44 Model 8904A NOTE The SHIFT key is the blue key The PRESET key is labeled in blue above the key After 3 seconds the display will time out and read as in step 1 Press SHIFT PRESET as often as needed to view the option and serial display The displayed option numbers are only two digits for example 01 even though the official option numbers are three digits for example 001 If the serial suffix is not 00000 but agrees with the suffix of the serial number
118. maintain the product in a safe condition SAFETY EARTH GROUND A uninterruptible safety earth ground must be provided from the main power source to the product input wiring terminals power cord or supplied power cord set SAFETY SYMBOLS Indicates instrument damage can occur if indicated operating limits are exceeded A Indicates hazardous voltages L Indicates earth ground terminal WARNING A WARNING note denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in personal injury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met CAUTION A CAUTION note denotes a hazard It calls attention to an operation procedure practice or the like which if not correctly performed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond an CAUTION note until the indicated conditions are fully understood and met 2 Chapter 1 Requlatory Information Updated March 1999 Safety Considerations for this Instrument WARNING This product is a Safety Class I instrument provided with a protective earthing ground incorporated in the power cord The mains plug shall only be inserted in a socket outlet provided with a protective earth contact Any interruption of the protective conductor inside or outside of the product is likely to make the product
119. n ac waveform of 80 to 300 Vpp should be observed The period should be approximately 2 ms The amplitude will vary with brightness of the display and is adjustable See Adjustment 5 Display Backlighting and Contrast in Section 5 of the Operation and Calibration Manual Display contrast is also adjustable Note that high voltages are measured CAUTION A no load or short on the backlighting oscillator of A2 will damage the drive circuit NOTE The display backlighting automatically turns off approximately 3 minutes after the last keystroke Pressing any key will turn the backlighting back on Troubleshooting Digital Display Interface 8 41 Service Model 8904A A3 OR A10 OUTPUT ASSEMBLY Description The following procedure will assist in locating a fault on the A3 or 10 Output Assembly It is wise to perform the procedure titled A2 Digital Assembly to A3 or A10 Output Assembly Interface first to confirm that the fault is indeed on the Output Assembly NOTE If the instrument has Option 002 a second output and the fault appears only on one output swap the A3 and A10 assemblies and see if the fault tracks the output assembly If it does then the Output Assembly is at fault otherwise the A2 Digital Assembly or possibly an interconnection is at fault Equipment Oscilloscope wi eee ees HP 1740A or Tektronix 2235 Procedure 1 If the Output Assembly is to be checked and the instrument also has 10
120. n figure 6 1 2712A to 2917A that secure the front panel assembly to the front frame item 89 6 Pull the front panel part way out until it is easy to access A1W1 Refer to figure 6 1 AIWI is the remaining wide ribbon cable at the front of the A2 Digital Assembly Unplug the cable from the A2 assembly 7 Pull the front panel further out to reveal the two T 8 Torx screws with lockwashers items 73 and 74 in figure 6 1 securing the line switch to the bottom the front panel then remove the two screws The screws will not be reused 8 Remove the front panel BNC connectors from the front panel There may be four two or no connectors depending on the presence of Option 002 and Option 004 Be sure to identify which cable goes in which hole A simple identification scheme is to put the nut back on the connectors for the HIGH outputs only The front panel should now be free of the instrument 9 Remove the LINE keycap from the line switch The switch s stem is easily snapped or pulled out of the switch s body When removing the keycap do not allow the stem to flex and do not hold the body of the switch Pull the keycap straight out 10 Press the new unlabeled keycap HP 0371 3802 on the line switch Transferring the A5 LCD Display 11 Remove the four Torx screws with lockwashers items 44 45 49 and 51 in figure 6 3 securing the old display shield item 39 to the old front panel and remove the display shield
121. ng like following then after about 10 seconds it will time out The example shows Option 003 now installed The presently installed options are HP 8904A Opts 02 01 03 After the 10 second timeout if the Codeword entry has been successful the display will read Option Firmware Installation Turn off LINE power to invoke options Troubleshooting Options 001 and 003 8 47 Service Model 8904A NOTE If a typing error occurs as the Codeword is being entered the backspace key can be used to back up to the digit in error b If the Codeword is incorrect the display will not list the desired option and after the 10 second timeout the display will read HP 8904 Main Selection Level fi Channel Config Begin again at step 3 6 Switch LINE to OFF and then back to ON After the instrument powers up the display should again read HP 8904A Main Selection Level 1 Channel Config 7 Press SHIFT PRESET Confirm that the option has been restored The display will look something like following The example shows that Option 003 has been installed HP 8904A Opts 02 01 03 Firmware Revision 18387A Serial No 12345 8 If another option is to be restored in the same instrument start again at step 3 8 48 Troubleshooting Options 001 and 003 Model 8904A Service HOW TO REPLACE THE MEMORY BACKUP BATTERY Description The battery that backs up non volatile memory has a limited lifetime
122. ng the Chassis 1 Remove the nuts from the present rear panel outputs with the 9 16 inch nut driver Do not press against the rear panel with the tool or scoring of the panel may occur 2 Remove the cable ties that secure the coaxial output cables to the sideframe by cutting them with diagonal cutters being careful not to score the soft insulation on the cables 3 Remove the necessary plastic hole plugs in the front panel by approaching them from inside the chassis with the needle nose pliers and squeezing in the small holding tangs on opposite sides of the plug Grasp the front of the plug with your fingers to pull it away from the panel Do not attempt to pry the plug out from the panel or the panel surface may get scarred rev 15DEC89 Rear to Front Panel Output Conversion 7 5 Instrument Changes Model 8904A Cable Routing 1 Refer to figures 7 1 7 2 and 7 3 Remove the BNC connector ends from the rear panel one at a time and insert them into the corresponding openings in the front panel After all of the connectors have been transferred to the front panel loop the cables and secure them to the front of the deck using the new cable ties as shown in figure 7 3 3 Install one nut on each connector Tighten the nuts on the BNC connectors hand tight using the nut driver The holes in the panel are D shaped and therefore prevent the connector from turning without having to tighten the nuts excessively Verify that t
123. nsformer s common terminal is connected to the earth terminal of the power source High voltages inside the instrument Areas with line voltages inside the instrument include the rear panel power supply and the line switch cable harness AC voltages as high as 300 V pp can be present on the backlighting drive to the LCD display The drive circuitry is on the front right corner of the A2 Digital Assembly Working around charged capacitors Capacitors inside the instrument can still be charged even if the instrument is disconnected from its source of supply Replacing line fuses Make sure that only 250 volt fuses with the required rated current and of the specified type normal blow time delay etc are used for replacement Do not use repaired fuses or short circuited fuseholders To do so could create a shock or fire hazard Disposing of the memory backup battery The memory backup battery on the A2 Digital Assembly is a lithium battery A2 is the large horizontal circuit board under the top cover near the front of the instrument The battery itself is near the front right corner of the board The following procedure is recommended for its disposal Discharge the battery by soldering a 50 resistor across both battery terminals Complete discharge will occur after one year at 25 C Under Resource Conservation Recovery Act RCRA regulations the com pletely discharged battery is considered nonhazardous However the us
124. nter should read within one count of 6 71088 MHz c Connect the counter to pin 2 of U2 The counter should read within one count of 1 67772 MHz 4a Digital to Analog Converter Check Using an Oscilloscope a On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in For A3 Output Assembly For 10 Output Assembly 1 Channel Config Channel Config NEXT NEXT NEXT WAVE FORM 11 WAVE FORM 4 FREQ 25 6 Hz FREQ 25 6 Hz AMPTD 10 V AMPTD 10 V NOTE Setting the frequency to exactly 25 6 Hz inputs a TTL squarewave to each input of the DAC latches As the DAC s data input lines are probed from the most significant bit the the least significant bit the frequency is consecutively divided by two b Connect a dc coupled high impedance oscilloscope to the pin of the IC listed below The waveform should be a TTL squarewave with an approximate period as indicated in the table IC on A3 or A10 Troubleshooting Digital Output Interface 8 33 Service Model 8904A 4b Digital to Analog Converter Check Using a Counter a If the counter has an external 10 MHz timebase reference input connect it to the rear panel 10 MHz REF OUT of the Multifunction Synthesizer NOTE If the counter does not have an external reference the readings in the following steps may be off several counts This does not indicate a failure b On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets
125. o instruments with serial numbers prefixed SERIAL PREFIXES 2712A to 2948A and all MAJOR changes that apply to your instrument rev 01JUL91 For additional important information about serial numbers refer to INSTRUMENTS COVERED BY THIS MANUAL in Section 1 Fourth Edition This material may be reproduced by or for the U S Government pursuant to the Copyright License un der the clause at DFARS 52 227 7013 APR 1988 Copyright HEWLETT PACKARD COMPANY 1987 EAST 24001 MISSION AVENUE TAF C 34 SPOKANE WASHINGTON U S A 99220 Service Manual HP Part 08904 90008 Other Documents Availiable Operation and Calibration Manual HP Part 08904 90007 Operation and Application Guide HP Part 5953 8491 Microfiche Service Manual HP Part 08904 90020 Microfiche Operation Calibration Manual HP Part 08904 90019 Printed U S A June 1992 D HEWLETT PACKARD 1 Regulatory Information Updated March 1999 Regulatory Information Updated March 1999 Safety Considerations GENERAL This product and related documentation must be reviewed for familiarization with safety markings and instructions before operation This product has been designed and tested in accordance with IEC Publication 1010 Safety Requirements for Electronic Measuring Apparatus and has been supplied in a safe condition This instruction documentation contains information and warnings which must be followed by the user to ensure safe operation and to
126. o the holes with your fingers The plugs fit tightly and will require some pressure to get them started in the holes 2 Replace the bottom cover by reversing the removal procedure 3 Type or write the date and option number on the new blank label in the following form day month year Opt 004 Peel off the protective backing and stick the label on the rear panel Do not place the label over the existing serial number tag Operation Verification 1 2 Connect the power cord and turn the instrument on The instrument should beep immediately upon power up and then again about 4 5 seconds later The display should read HP 8904A Main Selection Level f1 Channel Config Key in the following keys This will set up 5 dc the OUTPUTS 1 HIGH connector ground the LOW connector f1 Channel Config NEXT SHIFT FLOAT 1 OFF WAVE FORM AMPTD 5 V Connect a DC voltmeter set to measure a 5 V dc signal to the OUTPUTS 1 HIGH connector The voltmeter should read approximately 5 V dc If the instrument is equipped with a second output Option 002 key in NEXT SHIFT FLOAT 2 OFF WAVE FORM zz AMPTD 5 V Connect the DC voltmeter to the OUTPUTS 2 HIGH connector The voltmeter should read approximately 5 V dc Perform the AC and DC Amplitude Accuracy Test and the AC Amplitude Flatness Test Refer t the HP 8904A Operation and Calibration Manual Front to Rear Panel Output Conversion rev 15DEC
127. oduct Failure to ensure adequate earth grounding by not using this cord may cause product damage This product is designed for use in Installation Category and Pollution Degree 2 per IEC 1010 and IEC 664 respectively FOR INDOOR USE ONLY This product has autoranging line voltage input be sure the supply voltage is within the specified range Chapter 1 Regulatory Information Updated March 1999 To prevent electrical shock disconnect instrument from mains line before cleaning Use a dry cloth or one slightly dampened with water to clean the external case parts Do not attempt to clean internally Ventilation Requirements When installing the product in a cabinet the convection into and out of the product must not be restricted The ambient temperature outside the cabinet must be less than the maximum operating temperature of the product by 4 C for every 100 watts dissipated in the cabinet If the total power dissipated in the cabinet is greater than 800 watts then forced convection must be used Product Markings CE the CE mark is a registered trademark of the European Community A CE mark accompanied by a year indicated the year the design was proven CSA the CSA mark is a registered trademark of the Canadian Standards Association 4 Chapter 1 Model 8904A Contents CONTENTS Section 6 Replaceable Parts Introduction to This Section 6 1 Reference De
128. on to schematic diagrams procedures and component location diagrams Connection to circuit signifies measuring aid metal post circuit etc provided Piug in information number indicates pin XA2 of socket Model 8904A Interconnect information Circled letter with adjacent number indicates circuit path continuation to another service sheet 3 in this example Look for same circled letter on the indicated service sheet pM A OUTPUT ASSY ASSY 08620 60128 60129 SERIES REGULATOR 01 2 E A XXXX Serial prefix of instrument to which schematic directly applies Reference designations within outlined assemblies are abbreviated Full designation includes assembly number for example Ri of assembly 2 is 2 1 Designations of other components are complete as shown violet narrow stripe 8 4 Connector symbols within the borderlines of board assemblies signify connections to the assembly which are separate from those made through the integral plug part of the assembly Asterisk indicates factory selected components See Section S 3 Signal and ni HIGH XA TO ALC LOOP J3 not ya mounted on assembly 2 Non plug in information Solder point numbered 552 Large numbers in lower right corners of schematic diagrams are service sheet numbers Value selected for b
129. procedure After the serial number has been restored Options 001 003 and 005 can where applicable be restored The procedure requires entering of an option Codeword which is unique to the serial number and option number The Codeword is printed on a label inside the instrument The procedure is written with simple steps followed by detailed notes Normally it is only necessary to follow the simple steps and ignore the notes Refer to the notes when a step doesn t work quite right Procedure 1 Switch LINE to OFF and then back to ON After the instrument powers up the display should read HP 8904A Main Selection Level fi Channel Config 2 Press SHIFT PRESET Check that the serial suffix matches the number on the rear panel and check that the option being restored is not already present The display will look something like the following then after about 3 seconds it will time out The example shows an instrument with serial suffix 12345 with Options 002 and 001 installed HP 8904A Opts 02 01 Firmware Revision 18387A Serial No 12345 NOTE a The SHIFT key is the blue key The PRESET key is labeled in blue above the key b After 3 seconds the display will time out and read as in step 1 Press SHIFT PRESET as often as needed to view the option and serial display c If the serial suffix is 00000 the instrument will need its serial number entered Refer to How to Restore the Serial Number in a Replacement A2 A
130. r Other Service Documents Service Notes Manual Updates and other service literature are available through Hewlett Packard For further information about Manual Updates refer to Volume 1 paragraph 1 11 Recommended Test Equipment and Accessories Test equipment and test accessories required to maintain the Multifunction Synthesizer are listed in Table 1 2 Equipment other than that listed may be used if it meets the listed critical specifications 8 5 SCHEMATIC SYMBOLOGY AND SCHEMATIC DIAGRAM NOTES Table 8 1 summarizes the symbology used in presenting many devices found in the instrument The logic symbols used in this manual are based on the Institute of Electrical and Electronic Engineers IEEE IEEE STD 91 1984 Graphic Symbols for Logic Functions This publication may be purchased from Institute of Electrical and Electronic Engineers 345 East 47th Street New York NY 10017 8 3 Service Board Assembly designation Circuit functional title Socket designation on 2 assembly Wire color code Code used MIL STD 681 is the same as the resistor color code First number identifies the base color second number the wider stripe and the third number the narrower stripe Example denotes white base yellow wide stripe Table 8 1 Schematic Diagram Notes 1 of 11 Board Assembly Assembly name part number Board Test points symbols are numbered for easy correlati
131. r The insulator has a peal off adhesive backing Place it just behind the front perforations It should cover any scuff marks left by the heatsinks 7 10 CABINET PARTS COLOR CHANGE Serial Prefix 2914A and above NOTE Serial prefix 2914A changes the color of the instrument covers and accessories The old color cover and accessories are no longer available If your instrument has serial prefixes 2913A and below and you must replace one of these parts we recommend that you order the full set of covers and accessories Affected cabinet parts are items 61 67 and items 69 70 see table 6 3 7 14 Firmware Updates Hardware Modifications rev 15DEC89 Model 8904A Instrument Changes 7 11 MODIFICATION FOR FRONT PANEL ASSEMBLY Serial Prefix 2712A to 2917A INTRODUCTION HP part number 08904 61023 contains the parts to replace the front panel in HP 8904A Multifunction Synthesizers with serial prefix 2917A or below The front panel keys in these instruments may have a tendency to intermittently stay down when pressed This problem cannot usually be cured by mechanical adjustment of front panel parts or by replacement of individual parts The kit is easy to install and requires no special tools The contents of the kit are listed in table 7 3 The A5 LCD Display is not included in the kit and must be transferred from the old front panel assembly Table 7 3 Parts List for HP 08904 61023 Front Panel Kit Doo pe Keycap 0371 3802
132. r a track and hold circuit clean up filters amplifiers and attenuators reverse power protection Digital to Analog Converter Service Sheet 1 IC U6 is a 12 bit Digital to Analog Converter DAC Its function is to generate current with a magnitude proportional to the weighted 12 bit input data from DWSIC via latches U4 and U5 New data is output to the latches at a 1 6777216 MHz clock rate The latches hold the data until it is time to clock the data to the DAC Clocking of the latches is delayed 60 ns by U16 for optimum synchronization of the DAC and the following Track and Hold Circuit The output of the DAC is converted to a voltage by the series combination of resistors R210 R224 and R221 R224 DAC Level is adjusted to give the correct waveform amplitude Connector J4 is a convenient point for testing the DAC when jumper J201 is moved to connect point 2 to point 3 Track and Hold Circuit Service Sheet 1 After data is placed on the input of the DAC the DAC requires 300 ns that is one half clock period settling before its output is valid The Track and Hold circuit following the DAC stores holds the DAC s previous valid output on a capacitor C219 at the input of the Sampler Amplifier for 300 ns while the DAC with its new input data settles Then the DAC s output is sampled and tracked for 300 ns The Track and Hold Circuit can be divided into three parts e Sampler Drive e Sampler Switch e Sampler Amplifier Sampler
133. r to Section 7 for update information Factory Selected Component Refer to Section 5 A Errata part change rev 01NOV89 6 18 1 Replaceable Parts Reference Designation 14 wis W16 W17 2912A to 2942A W18 W25 29484 and above W18 W19 W20 W21 W22 W23 W24 W25 HP Part Number 08904 61004 08904 61006 08904 61008 08904 61008 5061 4837 5061 4837 08904 61015 08904 61015 08904 61007 08904 61007 08904 61007 08904 61007 Qty TRefer to Section 7 for update information 6 18 2 Table 6 3 Replaceable Parts Description RIBBON CABLE 16 CONDUCTOR REAR PANEL DIGITAL PORT TO A2J4 POWER SUPPLY WIRING HARNESS A4P3 TO A2J7 RIBBON CABLE 34 CONDUCTOR A2J5 TO A3J1 RIBBON CABLE 34 CONDUCTOR ADDED FOR OPTION 002 A256 TO A10J1 NOT ASSIGNED COAX CABLE FEMALE SMC SMC ADDED FOR OPTION 006 A3J400 TO A6J1 COAX CABLE FEMALE SMC SMC ADDED FOR OPTION 006 A3J401 TO A6J2 COAX CABLE ADDED FOR OPTION 006 A6J4 TO FRONT PANEL CH1 LOW COAX CABLE ADDED FOR OPTION 006 A63 TO FRONT PANEL CH1 HIGH COAX CABLE BNC PCB ADDED FOR OPTION 005 A2J12 TO REAR PANEL RESET INPUT COAX CABLE BNC PCB AODED FOR OPTION 005 A2J11 TO REAR PANEL RESET OUTPUT COAX CABLE BNC PCB ADDED FOR OPTION 005 A2J10 TO SYNC CLOCK IN COAX CABLE BNC PCB ADDED FOR OPTION 005 A2J9 TO SYNC CLOCK OUT Mfr Code 28480 28480 28480 28480 28480 28480
134. respond as shown in the table only for the keys in that group 8 38 Troubleshooting Digital Keyboard Interface Model 8904A NOTE f1 12 SHIFT 7 2 Alt other keys NEXT LAST LOCAL 3 9 Ail other keys 13 14 kHz V deg uV Ali other keys FREQ PHASE 2 5 0 All other keys D AMPTD WAVE FORM 6 All other keys INCR SET 1 4 Hz mV rad ENTER All other keys 1 NEXT 3 FREQ AMPTD 1 All other keys All keys All keys All keys All Keys All keys 2 FLOAT and ON Annunciators Check NOTE Troubleshooting Digital Keyboard Interface Ignore the beeper and the display as keys are pressed If pin 8 on A2U4 is always high a key is probably stuck down IC on A2 nd Key Pressed Response TTL Goes Low Always High Goes Low Always High Goes Low Always High Goes Low Always High Goes Low Always High Goes Low Always High Always Low Always High Blinks High Blinks High Blinks High Blinks High Blinks High If the instrument does not have Option 002 a second output omit the tests for FLOAT 2 and ON 2 Service On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in the sequence indicated listed in the following table The front panel annunciators should light as indicated in the table If the annunciators light improperly also check the logic level at the point 8 39 Service Model 8904A FLOAT 1 None SHIF
135. rom the Latch the waveform data is added to the Data in the Phase Adder If the Data is a constant assumed still to be four bits the waveform data is shifted delayed by the constant Figure 8 4 illustrates the delay generated by a Phase Adder P input of P 0 1 and 2 where P is the Data input to the Phase Adder The Q input to the Phase Adder is the bottom waveform of Figure 8 3 Generating a Sine Wave So far the waveform still a numerical representation is a staircase The staircase itself is one of the waveforms available at the channel outputs After analog conversion and filtering the waveform is a ramp To convert the staircase into a sine wave the data from the Phase Adder is fed into the Waveform Table a look up table resident in a read only memory ROM which digitally shapes the staircase Input the value of the staircase into the table and the ROM outputs the corresponding magnitude of a sine wave The process is illustrated in Figure 8 5 In the first example the frequency data into the P input of the Phase Accumulator is the constant 3 and the amp M Data into the P input of the Phase Adder is the constant 0 Figure 8 4 The Output of the Phase Adder for P 0 1 and 2 Principles of Operation Overall Model 8904A Service Figure 8 5 The Output of the Waveform Table with Data Bus Widths of 4 5 and 6 Bits With a four bit data bus the poor resemblance to a sine wave is apparent Wi
136. rt change 6 6 rev 01NOV89 Model 8904 Reference Designation A3C83 89 90 9 94 200 201 202 217 218 219 220 221 222 223 224 225 226 A3C227 228 A3C229 230 231 A3C232 233 299 A3C300 A3C301 A3C302 04 05 400 A3C401 402 HP Part Number 0160 4835 0160 4835 0160 4832 0160 4835 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4832 0160 4835 0160 4832 0160 4835 0160 4835 0160 4832 0160 4791 0160 4832 0160 4807 0160 4535 0160 4789 0160 4832 0160 4832 0160 4832 0160 3563 0160 4835 0160 4835 0160 4535 0160 0572 0160 0573 0160 4040 0160 4383 0160 4535 0160 4535 0160 4832 0160 4832 0160 4791 0160 4795 0160 4835 Refer to Section 7 for update information eh OG gt NN Aan A Table 6 3 Replaceable Parts Description NOT ASSIGNED 1UF 10 50VDC CER CAPACITOR FXD 1UF 10 50VDC CER NOT ASSIGNED CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 1UF 10 50VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01UF 10 100VDC CER CAPACITOR FXD 01
137. s 8 12 1 and 8 12 3 for serial prefix 2942A and below or 8 12 4 for serial prefix 2948A and above Rig up a temporary backup supply as follows a Temporarily solder one lead of a 10 resistor to the lead on the end of capacitor A2C5 Solder on the component side of the printed circuit board b If a power supply is used instead of a second battery set it to approximately 3V then switch it completely off Do not simply turn its voltage down to OV or the 10 resistor will load down the backup Solder the other lead of the resistor to the output of the power supply or the temporary backup battery 9 Solder the output of the power supply or battery to the other lead of 2 5 8 48 2 Troubleshooting Memory Backup Battery rev 15DEC89 Model 8904A 6a 6b Service Desolder the three leads of the backup battery A2B1 with a solder removal tool and remove the battery If the instrument has serial prefix 2942A and below put the three insulators HP 3050 0990 on the leads of the new battery A2B1 HP 1420 0281 and solder in the battery The bottom of the battery case must not touch the circuit board or any solder pads If the instrument has serial prefix 2948A and above solder in the battery A2B1 HP 1420 0338 7 Remove the resistor and temporary backup connections on the A2 assembly Re install the A2 assembly and all connectors 9 Place the instrument in its normal
138. se function generator which can output complex signals based on combinations of six waveforms e sine square sawtooth noise e triangle e dc Control over these signals includes e frequency e amplitude and e phase Signals can with Option 001 be combined by summation and or modulation The modulation formats are e AM e DSB e FM e pulse e Long complex sequences can with Option 001 be output based on e tones e DTMF Dual Tone Multi Frequency e digital Channel A can with Option 003 be phase continuous fast hopped with external control of e timing e frequency e amplitude e phase All of the above signal combinations can with Option 002 be output to a second port The output ports can be single ended or floating How Waveforms Are Generated Waveforms are generated by a numerical synthesis technique The heart of the synthesizer is a single digital waveform synthesis integrated circuit DWSIC For each channel the DWSIC generates a continuous stream of numbers which represent instantaneous levels of the waveform This digital waveform is then converted to an analog signal by a digital to analog converter or DAC one converter for each output port The analog signal is conditioned by high performance but conventional analog circuitry and routed to the output connector The conditioning circuits include a sample and hold to remove DAC switching noise filters to remove quantization noise th
139. sed NOTE The reference designators called out in the procedures are for the A3 or 10 Output Assembly 2 Power Supply Checks Connect a voltmeter to the points shown in Figure 8 12 Power Supply Testpoints on or 410 The readings should be very close to those indicated 3a Clock Checks Using an Oscilloscope NOTE This procedure is adequate for most cases Step 3b which uses a counter however is more exact a Connect a dc coupled high impedance oscilloscope to pin 3 of U2 The waveform should be TTL squarewave with a period of approximately 150 ns a frequency of 6 7 MHz b Connect the oscilloscope to pin 2 of U2 The waveform should be a TTL squarewave with a period of approximately 600 ns a frequency of 1 68 MHz 8 30 Troubleshooting Digital Output Interface Model 8904A Tools No 2 Pozidriv Screwdriver Needlenose Pliers PC Board Extractor included with Service Manual or order HP 08904 00013 Turn instrument off unplug power cord and remove bottom cover Disconnect ribbon cable W17 from A10J1 Remove hold down screw and washer from center of A10 Ouput Assembly using Pozidriv screwdriver Pull A10 from each of its seven mounting posts Release each mounting post by compressing the holding tang on mounting post with needienose pliers while applying gentle upward pressure with the PC board extractor Extractor should exert pressure on metal shield not on PC board except where
140. signations and Abbreviations Used in This Manual 6 1 Replaceable Parts Liste co 59e a ded Sed arene se woe IE de V ae ee ad 6 1 Ordering Parts c oup ue eem o Eo dx Rd eu vie EE Eds 6 1 Replaceable Parts List Updating Manual Updates 6 2 Mechanical and Chassis Part Locations and Reference Designations 6 2 Section 7 Instrument Changes Introduction to This Section 1 1 Option Conversions OLE ee de ob han token 7 1 Instrument Modifications 7 1 Firmware Updates A2U12 and 2013 7 8 Hardware 7 8 Modification for Possible Ground Wire Shock Hazard 7 9 Modification for Output Overvoltage Protection 7 13 Modification for Potential Power Supply 7 14 Section 8 Service Introduction to This Section 8 1 How the Section is Organized 8 1 Safety Considerations 472 leo Bh AA UTOR AE WIPE Ree t Hee GE ne Ys 8 1 Before Applying Power 11
141. ssembly d The displayed option numbers are only two digits for example 01 even though the official option numbers are three digits for example 001 e The presence of options other than the one being retrofit doesn t matter Troubleshooting Options 001 003 and 005 rev 15DEC89 Model 8904A Service 3 Key in SHIFT SPECIAL 4 8 ENTER SHIFT END The display should read Option Firmware Installation Enter installation code f4 Exit NOTE a The SPECIAL key is labeled in blue above the LAST key The END key is labeled in blue above the ENTER key b After keying in SHIFT SPECIAL the display should be 1 Special 0 42 Status Off 44 Exit 0 Last state recalled on power up c After keying in 4 8 the display should be fi Special 48 2 Status Off 4 Exit Last state recalled on power up d After keying in ENTER the instrument will beep e If after keying in SHIFT END if the display is Option Firmware Installation Option installation not performable the instrument will need its serial number entered or it is in need of repair Refer to How to Restore the Serial Number in a Replacement A2 Assembly 4 Locate the Codeword label for the option being restored The Codeword label is located on the right side of the chassis toward the rear of the instrument 5 Key in the Codeword then press ENTER Check the options from the display The display will look somethi
142. t this time 19 Connect the wide ribbon cable A1W1 in figure 1 from the new keyboard to the front of the A2 Digital Assembly Be careful not to bend any pins 20 Place the new front panel into the frame and loosely secure the assembly to the frame on the top and sides with the original screws Check that the cables to the front panel and the line switch keycap are positioned correctly before pushing the front panel completely into the frame 21 Tighten the screws in the frame in the following sequence item 76 80 81 75 78 77 then 79 Tighten the screws to 1 3 N m 11 in Ib If the top screws bind remove the front panel and repositioning the display shield installed in step 15 22 Position the line switch in the frame and the hole in the front panel then tighten the securing screws items 84 and 145 Tighten the screws to 1 3 11 23 Re install the BNC connectors to the new front panel as applicable Be sure the connectors go to the proper front panel holes 24 Reconnect the two connectors from the A5 LCD Display to the A2 Digital Assembly Final Assembly and Testing 25 Re install the top and side trim strips and the covers 26 Check the general functioning of the instrument by performing the Basic Functional Checks in the Operation and Calibration Manual Also check the functioning of all front panel keys and the line switch rev 15DEC89 Firmware Updates Hardware Modifications 7 17 Instrument
143. tegrated circuit microcircuit electron tube voltage regulator breakdown diode cable transmission path wire crystal unit piezo electric or quartz tuned cavity tuned circuit internal kilogram kilovolt inductance capacitance light emitting diode low frequency linear taper used in parts list lock washer low local oscillator logarithmic taper used in parts list logarithm c low pass filter low voltage meter distance milliampere maximum megohm meg 106 used in parts list metal film metallic oxide medium frequency microfarad used in parts list manufacturer milligram megahertz millihenry minute time minute plane angle miniature millimeter 6 3 Replaceable Parts 2 modulator momentary metal oxide semiconductor millisecond mounting meter indicating millivolt millivolt ac miltivoit dc millivolt peak millivolt peak millivoit rms milliwatt multiplex mylar microampere microfarad microhenry micromho microsecond microvolt microvolt ac microvolt dc microvolt peak microvolt peak to peak rms microwatt nanoampere no connection negative nanofarad nickel piate normaily open nominal negative positive negative negative positive zero zero tempera ture coefficient not recommended for field replacement not separately replaceabie nanosecond Table 6 2 Abbreviations 2 of 2 outside diameter oval head
144. th only four bit quantization the resolution is very coarse A vast improvement is made by increasing the number of quantization states by increasing the width of the data buses Examples of 5 and 6 bit data buses are also illustrated in Figure 8 5 In the instrument the bus width used in the DWSIC is actually 12 bits the total number of quantization levels is 212 4096 Controlling Amplitude The Amplitude Multiplier scales by digital multiplication the amplitude of the waveform data by the factor on the AM Data bus thus controlling the signal level For CW outputs the scaling covers a 2 1 range Further level control occurs in the analog output circuitry Further Digital Waveform Processing with Options Thus far all data inputs have been assumed to be constants which control frequency phase and amplitude In practice the data inputs may vary with time and thus modulate the waveforms This feature requires Option 001 In the Frequency Adder the Frequency Data is held constant to set the CW frequency the FM Data can be varied to generate FM In the Phase Adder M Data is varied to generate M In the Amplitude Multiplier the AM Data is held constant to set the CW level or it can be varied about the level constant to generate AM In addition to modulation waveforms from other channels can be summed digitally of course with channel one to create waveforms of specific shapes and characteristics Implementation of these additional capa
145. the available line voltage and that the correct fuse is installed An uninterrupted safety earth ground must be provided from the main power source to the instrument input wiring terminals power cord or supplied power cord set In addition verify that a common ground exists between the Multifunction Synthesizer and all test equipment Safety Pay attention to warnings and cautions They must be followed both for your protection and to avoid damage to the equipment Who should service the instrument Maintenance described herein is performed with power supplied to the instrument and with the protective covers removed Such maintenance should be performed only by service trained personnel who are aware of the hazards involved for example fire and electrical shock When maintenance can be performed without power supplied the power should be removed 8 1 Service 8 2 Model 8904A Proper grounding of the instrument Any interruption of the protective grounding conductor inside or outside the instrument or disconnection of the protective earth terminal will create a potential shock hazard that could result in personal injury Grounding one conductor of a two conductor outlet is not sufficient Whenever it is likely that the protection has been impaired the instrument must be made inoperative that is secured against unintended operation If this instrument is to be energized via an autotransformer make sure that the autotra
146. through the upper and lower portions of the amplifier for best high frequency balance The 16 and 16V power supply regulators Q300 and Q301 supply current to only the amplifier This minimizes the effects of the large current needs of the amplifier on the other circuits and minimizes distortion Overvoltage Protection and Output Circuits Service Sheet 4 Between the Floating Output Amplifier and the output connectors are several circuits Balun T400 improves the balance of the Floating Output Amplifier at high frequencies where the amplifier s balance has deteriorated The 48 dB Attenuator is a 500 pi section attenuator C505 compensates the high frequency effects of the parasitic capacitance of the contacts of K8 The Overvoltage Protection Circuits open the relays on the two output lines when a large voltage is inadvertently applied to an output connector The circuit thus protects the instrument s output circuits especially the Floating Output Amplifier Application of a large voltage on the output is sensed after attenuation by voltage dividers R490 and R491 and R492 and R493 by comparators U400A through U400D which are referenced to voltages from the voltage dividers R495 and R497 and R494 and R496 Both positive and negative references are sensed on both output lines When a comparator trips K402A and K402B are opened via flip flop U2B and drivers U10G U8D and U8E U2B also turns 033 which is read by the controller to g
147. tor electrical connector stationary portion coil inductor miscellaneous mechanical part electrical connector movable portion plug transistor SCR triode thyristor FET resistor thermistor transformer terminal board thermocouple test point Table 6 2 Abbreviations 1 of 2 ABBREVIATIONS coefficient common composition complete connector cadmium plate cathode ray tube complementary transistor logic continuous wave clockwise centimeter digital to analog decibel referred to 1 mw direct current degree temperature interval or difference degree plane degree Celsius centigrade degree Fahrenheit degree Keivin deposited carbon diameter diameter used in Parts fist DIFF AMPL amplifier differential division double pole double throw double sideband diode transistor digital voltmeter emitter coupled electromotive force NOTE All abbreviations in the parts list will be in upper case electronic data processing electrolytic encapsulated external 2 field effect transistor fillister head 2 frequency modulation front panel frequency germanium gigahertz glass ground ed heterodyne hexagonal hardware high frequency high Hewlett Packard high pass filter hour used in parts list high voltage integrated circuit inside diameter intermediate frequency impregnated incandescent include s input insulation Replaceable Parts in
148. ts The m is replaced with a number the identifier Comma AND Function Slant OR Function NOTE The identifier m is omitted if it is one that is when there is only depen dency relationship of that kind in a particular device When this is done the de pendency indicator itself G C EN or V is used to prefix or suffix the affected dependent input or output 8 10 Model 8904A Service Table 8 1 Schematic Diagram Notes 8 of 11 DIGITAL SYMBOLOGY REFERENCE INFORMATION Miscellaneous Schmitt Trigger Input characterized by hysteresis one threshold for positive going signals and a second threshold for negative going signals Active State A binary physical or logical state that corresponds to the true state of an input an output or a function The opposite of the inactive state Service Model 8904A Table 8 1 Schematic Diagram Notes 9 of 11 NAND GATE ji AND GATE B OR GATE WITH INVERTED INPUTS B A X B OR GATE AND GATE WITH INVERTED INPUTS pe X B BUFFER LE EXCLUSIVE OR GATE INVERTER OPEN COLLECTOR OPEN EMITTER OUTPUTS TTL OUTPUTS ECL EXTERNAL PULL UP RESISTOR INPUTS EXTERNAL PULL DOWN RESISTOR Model 8904A Service Table 8 1 Schematic Diagram Notes 10 of 11 ACTIVE LEVELS Active High Input ACTIVE HIGH inputs and outputs are indicated by the ab ACTIVE sence of the polarity indicator symbol 1 LEV
149. tters of Q201 and Q203 with a fixed dc offset C205 performs a similar function to the other half of the circuit Sampler Switch The Sampler Switch connects the DAC to the Sampler Amplifier during the sample half of the clock cycle the Sampler Switch is open during hold The switches are diodes U201A B C and F They are switched by the Sampler Drive through When the switch diodes are off diodes CR212 and CR208 charge capacitor C214 to approximately 2 7V The charge on C214 has no effect when the switch diodes are on but provides a strong initial backbias to the switch diodes as they turn off Principles of Operation A3 8 25 Service Model 8904A TO LOW PASS FILTER THIS LINE 15 AT GUARD TRACE POTENTIAL Figure 8 10 Simplified Diagram of the Sampler Amplifier Sampler Amplifier The Sampler Amplifier must accurately track the DAC output voltage when the Sampler Switch is closed and faithfully hold the sampled voltage when the switch is open For some waveforms for example square and ramp the DAC output may change abruptly several volts these transitions must pass through the Sampler Amplifier without distortion Refer to the simplified schematic of Figure 8 10 which shows the Sampler Amplifier without the guard traces The capacitor which holds the sampled voltage from the DAC is C219 It is followed by a unity gain amplifier which presents a very high impedance to C219 so as not to discharge it during t
150. wn Input When active causes the contents of a shift register to shift to the right or down m places m is replaced with a number Shift Left Up Input When active causes the contents of a shift register to shift to the left or up m places m is replaced with a number NOTE For the four functions shown above if m is one it is omitted The following functional labels are to be used as necessary in symbol build ups to ensure rapid identification of device function Counter Array of flip flops connected to form a counter with modules m m is re placed with a number that indicates the number of states 5 CNTR 10 CNTR etc Service 8 9 Service Model 8904A Table 8 1 Schematic Diagram Notes 7 of 11 DIGITAL SYMBOLOGY REFERENCE INFORMATION Sequential Logic Functions Cont d Register Array of unconnected flip flops that form a simple register or latch Shift Register Array of flip flops that form a register with internal connections that permit shifting the contents from flip flop to flip flop Read Only Memory Addressable memory with read out capability only Random Access Memory Addressable memory with read in and read out capability Dependency Notation Control Dependency Binary affecting input used where more than a simple AND relationship exists between the C input and the affected inputs and outputs used only with D type flip flops Gate AND Dependency Binary affecting input wit
151. y e setting and modulating its amplitude AM DATA FREQUENCY ADDER PHASE WAVEFORM FM DATA ACCUMULATOR TABLE FREQ DATA OUTPUT AMPLITUDE CLOCK MULTIPLIER Figure 8 2 Simplified Diagram of One Channel of the DWSIC 8 16 Principles of Operation Overall 100 88 Modei 904A Service In many ways the figure resembles an analog function generator and it may be helpful at times to visualize DWSIC operation using this analogy For example the Waveform Table is analogous to an analog shaping circuit However in the DWSIC all signal lines carry signal information as binary codes Thus the waveforms shown in the following figures are not really voltage versus time plots but are coded value versus time plots Conversion to an analog signal occurs at the output of the DWSIC and is not shown in Figure 8 2 It should be noted in Figure 8 2 that each interconnect line in the diagram generally represents a data bus several bits wide Generating Staircases in the Phase Accumulator Look first at the Phase Accumulator and Latch in Figure 8 2 The Phase Accumulator is a binary adder its output is the sum 0 The output of the Phase Accumulator is the data D input of the Latch This input is clocked through the latch once each period of the Clock input The output of the latch feeds back to the Q input of the Phase Accumulator For purposes of illustration assume all data is carried on four bit buses Also assum

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