Home

HP Washer/Dryer 4278A User's Manual

1. OoO0O000000000000000000 0000 XxX 4 15 1 If the power on test stops here A7 data acknowledgement circuit is faulty 2 f the power on test stops here the A20 is faulty 3 WM the power on test stops here A30 is faulty 4 16 One of the error messages listed in Table 4 2 will be displayed when the 4278A fails the power on self test Table 4 2 Error Message Error Message RAM TEST ERROR This message is displayed when the RAM read write test fails ROM CHECK SUM ERROR NO xx This message is displayed when the check sum of any of the programmed ROMs is incor rect The ROM number with this message is given in Figure 3 6 EEPROM CSUM ERROR NO 0 This message is displayed when the check sum of EEPROM 0 is incorrect The calibra tion data in the EEPROM is lost thus auto calibration refer to the paragraph 1 12 AUTO CALIBRATION must be performed EEPROM CSUM ERROR NO 1 This message is displayed when the EEPROM 1 check sum is incorrect The back up data compensation data etc in the EEPROM is lost A6 B d is not working This message is displayed when the A D con verter s End Of Conversion signal from the A6 board is not outp
2. O O NN Ct ME 04278 66501 Power Supply Board Assembly 04278 66502 Signal Source Board Assembly Standard 04278 66572 Signal Source Board Assembly Option 003 04278 66503 1MHz Transducer Board Assembly 04278 66504 1kHz Transducer Board Assembly 04278 66505 Switching Matrix Phase Detector Board Assembly 04278 66506 A D Converter Board Assembly 04278 66607 Digital Control Board Assembly without ROM 04278 66520 101 HP IB Board Assembly Option 101 only 04278 66530 201 Handler Interface Board Assembly Option 201 only Table 3 1 Replaceable Assembly List 2 3 Reference Designator Part Number Description 04278 66508 Input Switch Board Assembly excluding the shield covers 04278 66509 Keyboard Assembly 04278 66510 Memory Card Socket excluding the bezel and knob 04278 66513 DC AC Converter Board Assembly inside of the shield cover 04278 66590 Keyboard Display Control Board Assembly 04278 61100 LCD Module inside of the shield cover ex cluding the bezel and filter Table 3 1 Replaceable Assembly List 3 3 04278 00211 PANEL 1 F Option 201 04278 00210 PANEL HP IB Option 101 04278 00212 PANEL BLANK Standard Table 3 2 Coaxial Cable Assembly 04278 61607 04278 61606 04278 61605 04278 61604 04278 61603 04278 61602 04278 61601 04278 61612 04278 61613 A4J1 to A8J5 A3J2 to A8J6 A4J2 to A8J7 A
3. RAM TEST ERROR is displayed START What message is displayed ROM CHECK SUM ERROR NO xx is displayed Tuin off and replace the A7 board Turn on the 42784 the same message is displayed again turn oll and replace the A7 board Turn off and replace the faully ROM NOTE The ROM number and Me location is shown an the right y EEPROM CSUM ERROR NO 0 is displayed EEPROM CSUM ERROR NO 7 1 is displayed AG Bid is not working is displayed ANALOG TEST 1kHz FAILED or ANALOG TEST 1MHz FAILED is displayed Anather message displayed or a mearingless message is displayeci Figure 4 15 When The Cycle the 4278A off and on the same message is clis played again turn olf and replace the A7 board Calibrate the EEPROM as described in 1 12 Cycle the 4278A off and on Is the same message displayed Wait unlil the 4278A starts a Measurement Is the 4MHz clock TTL level present at AZ2TPO 4M on the A2 board The 4278A can be used but the back up data compensa tion data etc will be lost Are Ihe voltages within limits on the A1 board in Ihe following Turn off and replace the AG board Test voltage Point Limits A1TP12 GND AITP13 15 8V to 17 2V AITPI4 15 8V to 17 2V AITPI5 12 0 to 13 0V AITPIG 5 0V to 45 4V AITPI7 483V to 9
4. 3 Remove the 12 pin cable connected to the A90 assembly from the A91 assembly 4 Remove the 2 pin cable connected to the A9 assembly from the A91 assembly NOTE The A91 assembly consists of the LCD panel and the control circuit Do not dis assemble the LCD module the LCD panel and the circuit board must remain together as a unit 4 10 4 8 BLOCK DIAGRAM DISCUSSION Figure 4 6 shows the 4278A s analog circuit block diagram Knowing the function of every board will help you to isolate and troubleshoot the faulty assembly The A1 board is the switching power supply and supplies DC voltages to all assemblies and to the cooling fan on the rear panel The output voltages are 5V 12V 8V 15V 48V and 20V for the electronic circuits and 12V for the cooling fan The test signals are generated on the A2 board The test signal source is the 8 00MHz clock generator 8 08MHz on Option 003 units The A2 board supplies the test signal and digital clocking signals to synchronize the analog measurement circuit The differences between the A2 boards for 8 00MHz version and for 8 08MHz version are the crystal oscillator module and the ID jumper wire setting to be identified by the digital circuit The A3 board is the 1MHz transducer not installed on option 001 4278As The A3 board outputs a 1MHz signal whose amplitude and phase are proportional to the current flowing through the capacitor under test This circuit should be thought of
5. NOTE Use the special extractor tool HP P N 8710 1754 to prevent damaging the coaxial cables and connectors when removing them from the board 2 7 3 Change the parts for A2U24 to the 8 08MHz Clock Oscillator PN 1813 0551 from 8 00MHz Clock Oscillator PN 1813 0550 Figure 2 4 shows the location of A2U24 A2U24 Standard Frequency PN1813 0550 OPTION 003 PN1813 0551 Standard Q Q OPTION 003 Frequency Figure 2 4 Location of 2024 4 Disconnect the jumper soldered at position W1 and solder it to position W2 See Figure 2 4 5 Put the 66572 label over the 66502 printed on the A2 board 6 Reinstall the A2 board Then hang the coaxial cable on the cable clamp and the saddle edge Figure 2 1 shows the location of the saddle edge 7 Perform the adjustments described in paragraphs 1 8 1 9 1 10 and 1 12 2 8 2 6 OPTION 101 HP IB INTERFACE INSTALLATION The following procedure describes how to install Option 101 HP IB Interface in the 4278A REQUIRED PARTS Description Part Number Qty 101 HP IB Interface Board Assembly 04278 66520 Cable Assembly HP IB includes washers 04278 61621 Panel HP IB 04278 00210 Washer LK HLCR 2190 0577 PROCEDURE 1 Assemble the HP IB Cable Assembly and HP IB Panel as shown in Figure 2 5 CABLE ASSEMBLY HP IB PANEL HP IB Figure 2 5 HP IB Connector Panel Assembly NOTE The HP IB Cable Assembly includes a cover and two each
6. 2 8 Set the CAL menu page operating the key on the front panel Insert the memory card into the MEMORY card slot Press the 1kHz DATA softkey Press the MEMORY STORE softkey and ENTER key to store the standard s calibra tion values into the memory card Press the exit TABLE softkey Press the 1MHz DATA softkey Press the MEMORY STORE softkey and ENTER key to store the standards calibra tion values into the memory card Press the exit TABLE softkey HOW TO LOAD THE STANDARDS CALIBRATION VALUES PROCEDURE 1 2 Set the CAL menu page operating the key on the front panel Press the LOAD key to load the calibration values from the memory card Press the 1kHz DATA softkey and confirm that the data in the 1kHz STANDARD DATA TABLE is the same as your standards calibration values If the data repro duced in the 1kHz STANDARD DATA TABLE is not correct revise the data and save to the memory card again Press the exit TABLE softkey Press the 1MHz DATA softkey and confirm that the data in the 1MHz STANDARD DATA TABLE is the same as your standards calibration values If the data repro duced in 1MHz STANDARD DATA TABLE is not correct revise the data and save to the memory card again Press the exit TABLE softkey 1 25 1 12 3 CALIBRATION METHOD 1 1kHz CALIBRATION This paragraph describes the 1kHz calibration
7. A9 A10 A13 A90 or A91 assembly first disassemble the front panel assembly 1 Remove the top trim from the top of the front frame as shown in Figure 4 2 Figure 4 2 Top Trim Removal 2 Remove the two front feet from the bottom cover 3 Remove the three screws from the bottom of the front frame Remove the three screws from the top of the front frame o Carefully pull off the front panel assembly from the 4278A 4 7 5 AB ASSEMBLY REMOVAL Remove the front panel assembly from the 4278A as described in paragraph 4 7 4 1 Turn the 4278A upside down 2 Remove the two shield cases from the A8 assembly as shown in Figure 4 3 Figure 4 3 A8 Assembly Removal 3 Disconnect the four coaxial cables connected to the UNKNOWN connectors from the A8 assembly 4 Disconnect the seven coaxial cables from the A8 assembly Be sure to use the special extractor tool Refer to paragraph 4 6 5 Disconnect the 10 pin cable from the A8 assembly 6 Remove the four screws that secure the A8 assembly 4 7 6 A9 OR 90 ASSEMBLY REMOVAL First remove the front panel assembly from the 4278A as described in paragraph 4 7 4 1 2 Loosen the two hex setscrews on the CONTRAST knob and remove it Disconnect the flatcable assembly that is connected to the motherboard from the A90 assembly as shown in Figure 4 4 Disconnect the 3 and 12 pin cables from the A90 assembly Remove the eight screws that secure the A9 assembl
8. Term is displayed as shown in the Display2 This message means you may disconnect 100pF capacitor and connect the 1000pF capacitor While this mes sage is displayed the 4278A is writing calibration data to EEPROM Display 3 After the 4278A has completed writing the calibration data to the EEPROM Set up then press trigger will be displayed on the SYSTEM MESSAGE LINE as shown in Display 3 When this message is displayed the next measurement is available 1 27 4 Disconnect the 100pF standard capacitor after Display 3 is displayed and connect the 1000pF standard capacitor 5 Repeat steps 3 through 4 according to the connection order listed in Table 1 4 NOTE You can perform the calibration s procedure according to the display only NOTE The Processing Times shown in Table 1 4 are the approximate times from when you press the TRIGGER key until the next measurement will be available Table 1 4 1kHz Connection Order Connection Order Standard Connected 100pF capacitor a few seconds 1000pF capacitor a few seconds 0 01UF capacitor a few seconds 0 1UF capacitor a few seconds 1UF capacitor a few seconds OQ standard resistor a few seconds 10Q standard resistor about 8 sec 100pF capacitor a few seconds 16048A 1m test lead a few seconds 100pF capacitor 16048D 2m test lead 6 Confirm that 1kHz Calibration is Complete is
9. fax 305 269 7599 fax 64 4 495 8950 Canada J apan Asia Pacific tel 1 877 894 4414 tel 81 426 56 7832 tel 852 3197 7777 fax 1 888 900 8921 fax 81 426 56 7840 fax 852 2506 9284 Europe Australia tel 31 20 547 2323 fax 31 20 547 2390 Printed in USA July 2004 tel 1 800 629 485 fax 61 3 9210 5947 RES Agilent Technologies Notice The information contained in this document is subject to change without notice This document contains proprietary information that is protected by copyright All rights are reserved No part of this document may be photocopied reproduced or translated to another language without the prior written consent of the Agilent Technologies Agilent Technologies Japan Ltd Component Test PGU Kobe 1 3 2 Murotani Nishi ku Kobe shi Hyogo 651 2241 Japan Copyright Agilent Technologies Japan Ltd 1987 2000 Manual Printing History The manual printing date and part number indicate its current edition The printing date changes when a new edition is printed Minor corrections and updates that are incorporated at reprint do not cause the date to change The manual part number changes when extensive technical changes are incorporated February 1987 July 2000 First Edition part number 04278 90100 O t M E O Second Edition part number 04278 90100 Safety Summary The following general safety precautions must be observed during all phases of ope
10. lt 222670 4 26 A5 1MHz SWM PHD Test This test checks the switching matrix and phase detector used for the 1MHz mea surement function on the A5 board Perform this test after you confirm the A2 and A6 boards used in this test are working properly In this test the 4278A s setup is different from the typical measurement setup in order to check the switching matrix and phase detector as shown in the Figure 4 13 Etest Multi Slope A D Converter Multi Slope A D Converter Multi Slope A D Convertor Detection Phase Generator Figure 4 13 1MHz Switching Matrix and Phase Detector When this test is performed the internal test voltage signal E sy V is input to the switching matrix and the 4278A sets Si only of the switching matrix to ON The detected e E V is phase detected on the AS board and the detected e is converted to a digital value by the A6 board The amplitude value IA is calculated using the these digital values The 4278A repeats the preceding procedure changing only the ON switching ma trix switch from S2 to S4 Each amplitude value is calculated as VA when the 4278A sets only S2 to ON IB with only S3 ON and VB with only S4 ON This test will pass when the all calculated results are within the limits listed as follows Limit Values 156300 x la lt 234500 156300 lt Va lt 234500 156300 x lt 234500 156300 x Vs lt 234500 4 27 10 11
11. 1 will help you to locate the adjustment points Each adjustment procedure con tains a figure to help you locate the test points and to identify the required connectors and other related equipment REAR A3R31 A3R30 III A4R8 A1R52 E H 2813 1819 g A4R2 HH A4R1 B aoe A7 BOARD ASSEMBLY FRONT 1 7 INITIAL OPERATING PROCEDURE Before you start perform the BASIC OPERATING CHECK and the DISASSEMBLY pro cedures given in the following paragraphs to prepare the 4278A for adjustment The 4278A must be initialized set to its initial control settings before each adjustment as described in Section 3 of the Operation Manual Exceptions to these settings will be noted as they occur After you complete an adjustment reinitialize the 4278A NOTE The 4278A is initialized when it is turned on and when it receives an HP IB RST command OPERATIONAL VERIFICATION Check that the line voltage selector switch on the rear panel of the 4278A is properly set Turn the 4278A on and let it warm up for at least 30 minutes After the warm up period initialize the instrument If the 4278A fails its self test or if you can t initialize it refer to the troubleshooting procedures in Section 4 DISASSEMBLY TOP COVER REMOVAL To gain access to the adjustment points perform the following procedure 1 Remove the two plastic instrument feet located at the upper corners of the rear panel 2 Fully loosen t
12. 4 Adjust A2R13 OSC LVL 1k until the voltage reading of the 3400A is 1 04Vrms 0 01V Refer to Figure 1 1 for location of A2R13 NOTE The optimum test signal voltage for making 1kHz measurements is 1 04V which is higher than 1 00V because the output voltage will decrease due to the load impedance NOTE If your 4278A is equipped with Option 001 1kHz measurement only skip steps 5 and 6 5 Set the 4278A s controls as follows FREQUENCY 1MHz OSC LEVEL 1 0V 6 Set the voltage range of the 3400A to 3V and adjust A2R8 OSC LVL 1M for a coarse voltage reading of 0 7V then change the voltage range 1V and adjust A2R8 for a voltage reading of 0 99Vrms 0 01V NOTE The optimum test signal voltage for making 1MHz measurements is 0 99V which is less than 1 00V because the output voltage will increase when the test leads are extended 7 Disconnect the 3400A from the 4278A 1 10 1MHz TRANSDUCER ADJUSTMENTS This is a two step adjustment The first step adjusts the offset voltage of the second null amplifier and the second step adjusts the resonance frequency of the first null amplifier These adjustments are not necessary if the 4278A has Option 001 1 10 1 SECOND NULL AMPLIFIER OFFSET ADJUSTMENT The following adjustment minimizes the offset voltage of the integrator in the second null amplifier circuit This adjustment is performed using the 4278A s self test function EQUIPMENT OPEN Reference P O HP 16074A PROCEDUR
13. A te 305 267 4245 fax 305 267 4286 Australia New Zealand Agilent Technologies Australia Pty Ltd 347 Burwood Highway Forest Hill Victoria 3131 tel 1 800 629 485 Australia
14. Are the fuses blown on the A1 board Their location are given in Table 3 5 1 2 NO Replace the A1 board Figure 4 14 When The 4278A Will Not Be Turned On YES YES YES Remove the bottom cover Check the voltage et A11X1A 22 and A11X1B 22 is between 21 3V and 21 7V 15 the voltage within limits Turn off and replace the A1 board is the LINE VOLTAGE selector YES properly set Set the LINE VOLTAGE selec ior properly Replace the fuse with one of the correct rating Replace the blown fuse Go to the Digital Circuit Troubleshooting Procedure shown in the Figure 4 17 Replace the fuse with one of the carrect rating Disconnect the fine voltage input cable from A1 board WARNING DO NOT TOUCH ANY OF THE CONDUCTORS OF THE LINE VOLTAGE INPUT CABLE TPI3 TPIS Line Voltoge AIDS TPI TP a TPI7 Al component side YES Check the power line input circuit between the power fine receptacle and the power line input cable for the A1 board Cycle the 42784 off Does the fuse blow again Reconnect the line voltage input cable to the A1 board Turn on the 42784 LI E II E Front r LLL o mn 0 oo 32 30 25 22 20 15 10 Bo00000000000060000000000 00000 A 0000000000000 00o0 0000000000 A11X1 It the fuse blows again replace the A1 board Rear 4 33
15. Capacitor 10nF P O HP 16380C Standard Capacitor 100nF P O HP 16380C Standard Capacitor 1UF P O HP 16380C Standard Resistor 100 P O HP 16074A Reference for 10Q Standard P O HP 16074A SHORT Reference P O HP 16074A OPEN Reference P O HP 16074A Four Terminal Pair Test Leads 1m HP 16048 Four Terminal Pair Test Leads 2m HP 16048D Memory Card P N HP 04278 89001 The HP160744 or D test leads must be used do not make any substitutions 1 12 1 CALIBRATION SETUP Now you will set the 4278A s EEPROM write enable and operate the keys on the front panel to open the CAL menu page The following procedure is necessary when performing an auto calibration PROCEDURE 1 Turn the 4278A off and remove the A7 board assembly 2 Set the 4278A s EEPROM write protect jumper A7W2 to the right hand side as shown in Figure 1 10 A7 Digital Control Board Component Side Figure 1 10 EEPROM Write Enable 3 Install the A7 board assembly into the 4278A and replace the shield plate and top cover 4 Turn the 4278A on 5 Press the MENU and PREV keys on the front panel 6 Press the SVC FNCTN and CAL softkeys 1 20 7 Confirm that the display is as shown in Figure 1 11 CALIBRATION MENU lkHz STD DATA ENTRY 1MHz STD DATA ENTRY EXECUTE 1kHz CAL EXECUTE 1MHz CAL Figure 1 11 Calibration Menu Page 1 12 2 STANDARD DATA TABLE ENTRY This paragraph describes how to enter the calibration values for a st
16. IA IA JA 30800 0 9935 0 0 102500 0 9935 0 0 A5 1kHz SWM PHD Test This test checks the switching matrix and the phase detector used for the 1kHz measurement function on the A5 board Perform this test after you confirm the A2 and A6 boards used in this test are working properly In this test the 4278A setup is different from the typical measurement setup to check the switching matrix and phase detector as shown in the Figure 4 12 Multi Slope A D Converter Multi Slope A D Converter Multi Slope A D Convertor Multi Slope A D Converter 90 Detection Phase Generator Figure 4 12 1kHz Switching Matrix and Phase Detector During this test internal test voltage signal E V is input to the switching matrix and the 4278A sets only 51 of the switching matrix to ON The applied test signal e Ergg1 V is phase detected on the AS board and the detected e is con verted to a digital value on the A6 board The amplitude values IA are calculated using these digital values The 4278A repeats the preceding procedure changing only the switching matrix switch which is ON from S2 to S4 Each amplitude value Va is calculated when the 4278A sets only S2 ON IB with only S3 ON and VB with only S4 ON This test will pass when all calculated results are within the limits listed as follows Limit Values 164100 lt la lt 226700 164100 lt Va lt 226700 164100 lt lt 226700 164100 lt VB
17. Instali the 1kHz Transducer Board into the A4 slot as shown in Figure 2 1 Then place the coaxial cables on the cable clamp and the saddle edge see Figure 2 1 for the location of the saddle edge Remove the front panel assembly from the 4278A Refer to paragraph 4 7 4 for instructions on how to remove the front panel Connect coaxial cables A C and E from the A4 board to the A C and E connectors on the A8 board Cut the cable ties on the coaxial cables from the A8 board and bundle all of the coaxial cables including the A C and E cables and tie them together using the cable ties listed in the required parts list Replace the front panel assembly on the 4278A Perform the adjustments described in paragraphs 1 8 1 9 1 11 and 1 12 1 12 1 2 4 and 6 in sequence 2 6 2 5 OPTION 003 INSTALLATION The following procedure describes how to add Option 003 Test Frequency 1 Shift shift the test frequency of the 4278A by 1 to the 4278A NOTE If you want to change the test frequency from the 1 shifted frequency to the standard frequency reverse the operations in steps 3 4 and 5 of the following procedure REQUIRED PARTS 8 08MHz Clock Oscillator 1813 0551 1 LABEL 66572 5080 3152 1 PROCEDURE 1 Remove the top cover and the right hand side shield plate Refer to paragraph 1 7 for instructions on how to remove the top cover 2 Remove the A2 Signal Source board
18. Perform the analog circuit self tests NO 1 to NO 8 in the following order NO 8 NO 7 NO 6 NO 5 NO 4 NO 3 NO 1 and NO 2 The softkey selected self tests are described by self test number as follows A3 1MHz TRD C offset div test Checks the C offset current divider on the A3 board used for 1MHz high accuracy measurements Perform this test after confirming the A2 A5 and A6 boards used in this test are working properly In this test the 4278A s setup is different from the typical measurement setup in order to check the C offset current divider as shown in the Figure 4 7 Phase Qvo von io O 490 Detector C offset C oY Converter Current N Divider Figure 4 7 C offset Current Divider During this test internal test current E l is applied to the C offset current divider and the divided current is converted into voltage signal e by the second null amplifier e is phase detected on the A5 board and the detected e is con verted to a digital value on the board The internal test voltage E V is applied directly to the A5 board as ey ey is phase detected on the 5 board and the detected e is converted to a digital value on the A6 board The digital values of e and e are used to calculate the ratio e ey The 4278A changes only the setting of the C offset current divider and repeats the measure ment again and calculates the ratio e e Finally the two calculated ratios are used to calcul
19. TENANCE SHOULD BE PERFORMED BY TRAINED SERVICE PERSONNEL ONLY 4 3 RECOMMENDED TEST EQUIPMENT The test equipment required for performing the procedures given in this section are listed in Table 1 1 Section 1 The table includes the type of instrument required critical specifica tions and model numbers for the recommended equipment If the recommended models are not available equipment which meets or exceeds all critical specifications may be substituted 4 1 4 4 AFTER SERVICE PRODUCT SAFETY CHECKS WHENEVER IT APPEARS LIKELY THAT PROTECTIVE SAFETY PROVISIONS HAVE BEEN IMPAIRED THE APPARATUS SHALL BE MARKED AS INOPERATIVE AND SHOULD BE SECURED AGAINST ANY UNINTENDED OPERATION THE PROTECTION PROVISIONS WILL HAVE LIKELY BEEN COMPROMISED IF FOR EXAMPLE INSTRUMENT SHOWS VISIBLE DAMAGE THE INSTRUMENT FAILS TO PERFORM THE INTENDED MEASUREMENT THE UNIT HAS UNDERGONE PROLONGED STORAGE UNDER UNFAVORABLE CONDITIONS THE INSTRUMENT WAS SEVERELY STRESSED IN TRANSPORT Perform the following five checks to verify the safety of the 4278A these checks may also be used to check for safety after troubleshooting and repair 1 Visually inspect the interior of the instrument for any signs of abnormal internal ly generated heat such as discolored printed circuit boards or components damaged insulation or evidence of arcing Determine the cause and repair Use an ohmmeter capable of accurately measuring 0 50 to check t
20. To A7TP2 HP3478A 060006 o BORGO no onmono Figure 1 5 Power Supply Voltage Adjustment Setup 2 Set the 3478A s controls as follows FUNCTION DCV RANGE AUTO 3 Connect the LO lead of the 3478A to A7TP2 and the HI lead to A7TP1 Figure 1 6 shows the location of test points ATTPl A7TP2 Figure 1 6 Voltage Adjustment Access Locations 4 Turn A1R52 V ADJ fully CCW 5 Adjust A1R52 until the voltage reading of the 3478A is 5V 0 05V 6 Remove the test leads and turn off the 4278A 7 Reinstall the left hand side top shield plate on the A1 board 1 9 SIGNAL SOURCE ADJUSTMENTS This is a two part adjustment in the first part you will adjust the 1kHz test signal voltage and in the second part you will adjust the 1MHz test signal voltage EQUIPMENT RMS Voltmeter HP 3400A BNC m to BNC m Cable 30cm PN 8120 1838 PROCEDURE 1 Set the voltage range on the 3400A to 3V 2 Connect INPUT of the 3400A and the UNKNOWN Hcur terminals of the 4278A using the BNC cable as shown in Figure 1 7 HP4278A HP3400A BNC to BNC Cable Figure 1 7 Signal Source Adjustments Setup NOTE The length of the BNC cable used in this adjustment must be less than 50cm NOTE If your 4278A is equipped with Option 002 1MHz measurement only skip steps 3 and 4 3 Set the 4278A s controls as follows FREQUENCY 1kHz OSC LEVEL 1 0V
21. are installed in the 4278A by reading the ID signal bus and the settings of the A7S3 switches The ID signal bus gives the information of which version A2 board is installed 8 00MHz or 8 08MHz Option 003 whither or not the A3 board is installed Option 001 and whither or not the A4 board is installed Option 002 The information on whether the 4278A is configured as option 101 or not and whether the 4278A is configured as Option 201 or not is determined by reading the settings of the A7S3 switches No Option Option Options Interface 101 only 201 only 101 201 The A8 board is the input switch and is located just behind the UNKNOWN terminals The A8 board outputs the test signal from the A2 board to the Hoy terminal The and Loup Signals are connected to the A3 A5 board or to the A4 board depending on the test frequency selected The A9 board is the front panel keyboard Key switches LED indicators and the CONTRAST adjustment potentiometer are located on the A9 board The A10 board is the memory card socket board The only component on this board is the memory card connector The A13 board is the DC to AC converter which supplies approx 600 Vac to backlight the LCD The A20 and the A30 boards are the HP IB and the Handler interfaces respectively The A90 board is the display and the keyboard control circuit This interfaces the digital control circuit on the A7 board to the LCD module and the switches and
22. as a current to voltage phase converter The A4 board is the 1kHz transducer not installed on Option 002 4278As The A4 board outputs two 1kHz signals one whose amplitude and phase are proportional to the current flowing through the capacitor under test and the other is the buffered voltage applied to the capacitor under test The A5 board contains the switching matrix and phase detectors There are four inputs to the A5 board the voltage across the capacitor under test for the 1kHz and 1MHz measure ments and the voltage proportional to the current flowing through the capacitor under test for 1kHz and 1MHz measurements There are four phase detectors to detect the 0 and 90 components of the voltage proportional to the current flowing through the capacitor under test and the voltage applied to the capacitor under test The switching matrix routes the signals between the inputs and the phase detectors The A6 board contains the four multi slope A D converters used to digitize the four output voltages from the A5 board The A7 board is the digital control board This board controls all measurement circuits and interfaces The clock frequency is 7 92MHz There are two EEPROMs on the A7 board One is usually write protected and has the analog circuit s calibration data is stored in it and the other is not write protected and the instrument s back up data compensation data etc is stored in it The A7 board determines which Options
23. as zero NOTE When using the HP 16380C capacitors as the calibration standards use the cali brated capacitance given in the calibration data sheet supplied with the 16380C determine the value for the dissipation factor by reading the supplied graph NOTE The HP 16074A s 109 standard s calibrated value resistance and inductance will be given as the difference between the 0Q and the 10 standard If you use the standard enter the difference between the 100 standard s values and OQ stan dard s values 1 22 3 Confirm that the standard s calibration values are correctly entered into the 1kHz STANDARD DATA TABLE Refer Figure 1 12 1kHz STANDARD 100pF 1000pF 0 01uF 0 1puF luF 102 02 STANDARD DATA TABLE 099 9960 0999 980 010 0006nF 0100 007nF 1 000005yF R 09 62100 Q MEMORY D STORE 0 000000 0 000000 0 000100 0 000250 000 0000 L 000 0000nH Figure 1 12 1kHz Standard Data Table Example 4 Press the exit TABLE softkey 1 23 2 1MHz STANDARD DATA TABLE ENTRY The following describes how to enter the standard s calibration values into the 1MHz STAN DARD DATA TABLE Skip this paragraph if your 4278A does not have the 1MHz measure ment function PROCEDURE 1 Press the 1MHz DATA softkey 2 Use the numeric ENTRY and ENTER keys to enter the standard s calibration values into the STANDARD DATA TABLE NOTE When you use the 16380A capacitors as the standar
24. be connected to ground in the manner described in the installation operating manual and before operating the equipment Frame or chassis terminal A connection to the frame chas sis of the equipment which normally includes all exposed metal structures Alternating current power line Direct current power line Alternating or direct current power line A WARNING denotes a hazard It calls attention to a pro cedure practice condition or the like which if not correctly performed or adhered to could result in injury or death to personnel The CAUTION sign denotes a hazard It calls attention to an operating procedure practice condition 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 A Note denotes important information It calls attention to a procedure practice condition or the like which is essential to highlight Table of Contents HOW TO USE THIS MANUAL SECTION 1 ADJUSTMENTS SECTION 2 OPTION INSTALLATION MODIFICATION SECTION 3 REPLACABLE ASSEMBLIES SECTION 4 ASSEMBLY LEVEL TROUBLESHOOTING APPENDICES A MANUAL CHANGES 1 1 2 1 4 1 A 1 CONTENTS SECTION 1 ADJUSTMENTS 1 1 INTRODUCTION 1 1 1 2 SAFTY CONSIDERATIONS 1 1 1 3 TESTT EQUIPMENT 1 2 1 4 ADJUSTMENT COMPONENTS 1 2 1 5 ADJUSTMENT INTERACTIONS 1 3 1 6 ADJUSTMENT LOCATIONS 1 3 1 7 INTERNAL OPERATING PROCEDURE 1 3 1 8 POWE
25. the cable ties on the coaxial cables from the A8 board then bundle and tie all of the coaxial cables together including cables B and D using the cable ties listed in the required parts list Reinstall the 4278A front panel assembly Perform the adjustments described in paragraphs 1 8 1 9 1 10 and 1 12 1 12 1 3 5 and 6 in sequence 2 4 ADDING 1kHz MEASUREMENT CAPABILITY TO OPTION 002 HP 4278As The following procedure describes how to add 1kHz measurement capability to Option 002 1MHz Test Frequency Only HP 4278As REQUIRED PARTS 1kHz Transducer Board Assembly 04278 66504 Coaxial Cable Assembly A 04278 61607 Coaxial Cable Assembly C 04278 61605 Coaxial Cable Assembly E 04278 61603 Cable Tie 1400 1361 NOTE The letters in parentheses are the letters on the wire markers PROCEDURE 1 Remove the top cover and the right hand side shield plate Refer to paragraph 1 7 for instructions on how to remove the top cover 2 Connect the three coaxial cables listed in the required part list to the three con nectors on the 1kHz Transducer Board Assembly as shown in Figure 2 3 NOTE The letter on the cable marker should match the letter marked beside the connec tor on the board NOTE Use the special extractor tool HP P N 8710 1754 to prevent damaging the coaxial cables and connectors when removing them from the board 2 5 Figure 2 3 1 2 Transducer Board
26. 12 13 14 A6 ADC Test This test checks the four analog to digital converters converters on the A6 board In this test the 4278A s setup is different from the typical measurement setup to check the A D converters The four A D converters each have their own offset circuit and offset value When this test is performed the offset value for each A D converter is used when that converter is under test The A D converter test values are displayed as ADC1 ADC2 ADC3 and ADC4 This test will pass when the test values of the four multislope converters within the following limits Limit Values 197000 lt ADCI lt 240000 197000 lt ADC2 lt 240000 197000 lt ADC3 lt 240000 197000 lt ADC4 lt 240000 ROM Check Sum Display This test lists the check sum of all programmed ROMs If any of check sums are incorrect the 4278A will stop during the power on self test therefore you normally won t need to perform this self test Memory Card R W Test This test performs a read write test of the memory card This test will overwrite any test data on the memory card thus destroying the stored data LED Display Test This test repeatedly turns the LED indicators on the front panel ON and OFF LCD Display Test This test repeatedly reverses all dots on the LCD panel except for the dots for the lines that partition the softkey labels which will remain on Handler I F Test This test sequentially activate
27. 16048A HP 16048D PN 04278 66597 PN 8710 1754 A Adjustments T Troubleshooting Table 1 2 Adjustable Components Adjustable Adjustment Description Component Name A3R30 ORG OFS ADJ 1MHz Transducer Second Null Amplifier A3R31 Offset Voltage Adjustment A3C12 RES FREQ ADJ 1MHz Transducer First Null Amplifier Resonance Frequency Adjustment A4R1 I V OFFSET ADJ ikHz Transducer l V Converter DC Offset Voltage Adjustment A4R2 ICH OFFSET ADJ 1kHz Transducer Current Channel DC Offset Voltage Adjustment A4R8 VCH OFFSET ADJ 1kHz Transducer Voltage Channel DC Offset Voltage Adjustment Table 1 3 Required Adjustments Assembly Replaced or Repaired Adjustments Required paragraph Power Supply 1 8 1 11 Signal Source 1 9 1 10 1 12 MHz Transducer 1 9 1 10 1 12 1kHz Transducer 1 9 1 11 1 12 Switching Matrix Phase Detector NONE A D Converter NONE Digital Control Input Switch Keyboard Memory Card Socket Motherboard DC AC Converter 101 HP IB 201 Handler Interface Keyboard Display Control LCD Module 1 7 1 8 POWER SUPPLY ADJUSTMENTS The following two part procedure adjusts the switching frequency and the output voltage of the switching power supply 1 8 1 POWER SUPPLY SWITCHING FREQUENCY ADJUSTMENT Adjusts the switching frequency of the power supply EQUIPMENT Oscilloscope HP 1740A 10 1 Divider Probe 1MQ HP 10040A PROCEDURE 1 Make sure that the 4278A is turned off 2
28. 1V A1TP18 12 0V to 13 0V Turn off and replace the A2 board Turn off and replace the A1 board PONES Fura off and change to the Analog Circuit 753 7 to the right hand side Troubleshooting Procedure in position on Figure 4 16 NOTE NOTE When the 42784 fails the analog circuit test of the power on self test the 4278A will stop anti will not start measurement in order to let the operator know that the 42784 will not work properly However once the 4278A fails the power on self test you can t troubleshoot it becauso the 4278A will not operate any more Setting A783 7 ta on ignores the test results and make it possible to troubleshoot the 32784 After the troubleshooting reset 793 7 to the left hand side position OFF When A7S3 7 is kept on the power on self test results are ignored and you will nat know if the instrument fails Be sure and restore the bit switch after troubleshooting is complete if you change bil switch 753 Is RAM fEST ERROR ROM CHECK SUM ERROR NO xx is displayed NO Cycle the 42784 off and on yrs Turn aff and then set ail bits Is the any message displayed of 753 to the left hand side yet position OFF NOTE Turn on Ihe 4278A or Turn off and replace the A7 board Turn off and repiace the board Qe sure and restore the bit switch after troubleshooting is complete if
29. 3J1 to A8J8 A4J3 to A8J9 A5J2 to A8J10 A2J1 to A8J11 to A5J3 A3J4 to A5J1 Table 3 3 Flat Cable Assembly 04278 61621 CABLE ASSY HP IB Option 101 A20J1 to PANEL HP IB 04278 61622 CABLE ASSY 1 F Option 201 A30J1 TO PANEL I F Table 3 4 Wire Assembly A8J12 to 11 3 10 pin Part Number 04278 61614 04278 61615 A13J2 to A90J5 3 pin 04278 61616 A90J4 to A91J1 12 pin 04278 61630 A13J1 to A91J2 3 pin 04278 61631 A9J1 to A91J3 2 pin Table 3 5 Replaceable Fuse List 1 2 Reference Designator Part Number 2110 0014 FUSE 4A 250V TD 1 25X 25 UL 2110 0746 FUSE 4A 125V NTD UL 2110 0746 FUSE 4A 125V NTD UL 2110 0741 FUSE 1A 125V NTD UL 2110 0741 FUSE 1A 125V NTD UL 2110 0743 FUSE 2A 125V UL 2110 0743 FUSE 2A 125V UL 2110 0743 FUSE 2A 125V UL 2110 0663 FUSE THERMAL 96 C Table 3 5 Replaceable Fuse List 2 2 Reference Designator Parts Number Qty 1 2110 0741 FUSE 1A 125V NTD UL 2110 0742 FUSE 1 5A 125V NTD UL 2110 0741 FUSE 1A 125V NTD UL Table 3 6 Replaceable ROM and Fuse List 04278 85501 04278 85502 04278 85503 04278 85504 04278 85505 04278 85506 04278 85507 04278 85508 2110 0743 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 ROM Version 2 0 FUSE 2A 125V UL SECTION 4 ASSEMBLY LEVEL TROUBLESH
30. E 1 Connect the OPEN reference to the UNKNOWN terminals 2 Press the MENU and PREV keys in sequence 3 Press the SVC FNCTN SELF TEST and TEST NO softkeys in sequence 4 Press the 4 and ENTER keys in sequence 5 Press the TEST START softkey 6 Adjust A3R30 and A3R31 ORG OFS ADJ alternately so that the displayed result on the LCD is less than 0 00003 and minimum 7 Press the ABORT TEST and TEST MENU softkeys in sequence to return to the test menu 8 Disconnect the OPEN reference from the UNKNOWN terminals NOTE Continue on to the next adjustment without resetting the 4278A 1 10 2 FIRST NULL AMPLIFIER RESONANCE FREQUENCY ADJUSTMENT Adjusts the resonance frequency of the first null amplifier This adjustment is performed using the self test PROCEDURE hs 2 Press the TEST NO softkey Press 3 and ENTER in sequence Press the TEST START softkey Adjust A3C12 RES FREQ ADJ for a maximum readout on the LCD NOTE Confirm that the maximum value in step 4 is between 0 04 and 0 4 If the value is out of range troubleshoot the A3 board 1 11 1kHz TRANSDUCER ADJUSTMENTS This three part procedure is used to adjust the DC offset voltage of I ch l V Converter and the DC offset voltages of the I ch and V ch outputs EQUIPMENT Digital Voltmeter HP 3478A Dual Banana Plug to Alligator Clip Cable HP 11002A 1 11 1 I V CONVERTER OFFSET VOLTAGE ADJUSTMEN
31. IONS TOOLS AND FASTENERS DISASSEMBLY 4 7 1 4 7 2 4 7 3 4 7 4 4 7 5 4 7 6 4 7 7 COVER REMOVAL A1 ASSEMBLY REMOVAL A2 A3 A4 A5 A6 A7 A20 0R A30 ASSEMBLY REMOVAL FRONT PANEL DISASSEMBLY A8 ASSEMBLY REMOVAL A9 OR A90 ASSEMBLY REMOVAL A10 ASSEMBLY REMOVAL 2 1 2 1 2 3 2 5 2 7 2 9 2 11 3 1 3 1 3 1 3 1 4 1 4 1 4 1 4 2 4 3 4 4 4 4 4 4 4 5 4 6 4 7 4 9 4 7 8 A13 ASSEMBLY REMOVAL 4 7 9 A91 ASSEMBLY REMOVAL 4 8 BLOCK DIAGRAM DISCUSSION 4 9 TROUBLESHOOTING 4 9 1 SELF TEST 4 9 TROUBLESHOOTING PROCEDURE APPENDIX A MANUAL CHANGE 4 10 4 11 4 15 4 15 4 31 SECTION 1 ADJUSTMENTS 1 1 INTRODUCTION 1 1 1 2 SAFETY CONSIDERATIONS 1 1 1 3 TEST EQUIPMENT 1 2 1 4 ADJUSTABLE COMPONENTS 1 2 1 5 ADJUSTMENT INTERACTIONS 1 2 1 6 ADJUSTMENT LOCATIONS 1 3 1 7 INITIAL OPERATING PROCEDURE 1 3 1 8 POWER SUPPLY ADJUSTMENTS 1 8 1 8 1 POWER SUPPLY SWITCHING FREQUENCY ADJUSTMENT 1 8 1 8 2 POWER SUPPLY OUTPUT VOLTAGE ADJUSTMENT 1 10 1 9 SIGNAL SOURCE ADJUSTMENTS 1 12 1 10 1MHz TRANSDUCER ADJUSTMENTS 1 14 1 10 1 SECOND NULL AMPLIFIER OFFSET ADJUSTMENT 1 14 1 10 2 FIRST NULL AMPLIFIER RESONANCE FREQUENCY ADJUSTMENT 1 15 1 11 1kHz TRANSDUCER ADJUSTMENTS 1 16 1 11 1 TRANSDUCER OFFSET VOLTAGE ADJUSTMENT 1 16 1 11 2 CURRENT CHANNEL AMPLIFIER OFFSET VOLTAGE ADJUSTMENT 1 17 1 11 3 VOLTAGE CHANNEL AMPLIFIER OFFSET VOLTAGE ADJ
32. Loosen the two screws holding the left hand side top shield plate the shield plate on which the WARNING message is printed and remove it DANGEROUS VOLTAGES ARE PRESENT ON THE A1 BOARD DON T TOUCH ANYPLACE EXCEPT WHERE INSTRUCTED TO 3 Connect the 10040A to the CHAN A INPUT of the 1740A Figure 1 2 shows the setup for this adjustment HP1740A HP4278A O AE AGS he GE ZAR e 50666 Figure 1 2 Power Supply Frequency Adjustment Setup 4 Set the 1740A s controls as follows INPUT A DC 1MQ CHAN A Vertical 1V DIV TIME BASE 2usec 5 Connect the probe s ground lead to A1TP12 Connect the probe tip to A1TP11 Figure 1 3 shows the access and the adjustment locations A1R19 A1R52 ALTP 12 A1TP11 Figure 1 3 Switching Frequency Adjustment Locations 6 Turn on the 4278A 7 Adjust A1R19 FREQ ADJ until the period T of the waveform is 12 5us 0 5us as shown in Figure 1 4 Figure 1 4 Switching Waveform 8 Disconnect the probe from the 4278A 1 9 1 8 2 POWER SUPPLY OUTPUT VOLTAGE ADJUSTMENT This adjustment sets the output voltages of the power supply EQUIPMENT Digital Voltmeter HP 3478A Dual Banana Plug to Alligator Clip Cable HP 11002A PROCEDURE 1 Connect the 11002A to the 3478A s INPUT Figure 1 5 shows the equipment setup To A7TP1 Banana Plug to Alligator HI lead Clip Cable HP4278A Oiga ETEL Ey i
33. OOTING 4 1 INTRODUCTION 4 1 4 2 SAFETY CONSIDERATIONS 4 1 4 3 RECOMMENDED TEST EQUIPMENT 4 1 4 4 AFTER SERVICE PRODUCT SAFETY CHECKS 4 2 4 5 ASSEMBLY DESIGNATIONS 4 3 4 6 TOOLS AND FASTENERS 4 3 4 7 DISASSEMBLY 4 4 4 7 1 TOP COVER REMOVAL 4 4 4 7 2 A1 ASSEMBLY REMOVAL 4 4 4 7 3 A2 A3 A4 A5 A6 A7 A20 OR A30 ASSEMBLY REMOVAL 4 5 4 7 4 FRONT PANEL DISASSEMBLY 4 6 4 7 5 AB ASSEMBLY REMOVAL 4 7 4 7 6 A9 OR A90 ASSEMBLY REMOVAL 4 8 4 7 7 A10 ASSEMBLY REMOVAL 4 9 4 7 8 A13 ASSEMBLY REMOVAL 4 9 4 7 9 91 ASSEMBLY REMOVAL 4 10 4 8 BLOCK DIAGRAM DISCUSSION 4 11 4 9 TROUBLESHOOTING 4 15 4 9 1 SELF TEST 4 15 4 9 2 TROUBLESHOOTING PROCEDURE 4 31 SECTION 4 ASSEMBLY LEVEL TROUBLESHOOTING 4 1 INTRODUCTION This section provides the information and instructions required for assembly level trouble shooting and repair of the HP 4278A 1kHz 1MHz Capacitance Meter The rest of this sec tion is divided into three parts Part 1 contains the information you need to know before using the troubleshooting procedures Part 2 explains the 4278A s block level circuit opera tion Part 3 gives the troubleshooting procedures 4 2 SAFETY CONSIDERATIONS This section contains WARNINGS and CAUTIONS which must be followed for your safety and to avoid damaging the equipment Notes are included for clarification MAINTENANCE DESCRIBED HEREIN IS PERFORMED WITH POWER SUPPLIED TO THE INSTRUMENT AND PROTECTIVE COVERS REMOVED SUCH MAIN
34. OPERATING PERSONNEL MUST NOT REMOVE INSTRUMENT COVERS COMPO NENT REPLACEMENT AND INTERNAL ADJUSTMENTS MUST BE MADE BY QUALIFIED MAINTENANCE PERSONNEL WHO HAVE RECEIVED SERVICE TRAINING FOR THE HP 4278A HOW TO USE THIS MANUAL This Maintenance Manual is for the HP 4278A 1kHz 1MHz Capacitance Meter Both the Operation and the Maintenance Manuals are needed to service the HP 4278A at the assem bly replacement repair level Refer to the Operation Manual for information on operating the 4278A This manual includes information for adjusting and repairing the 4278A at the as sembly level The contents of this manual are described below Section 1 ADJUSTMENTS Section 1 provides the information necessary to adjust the 4278A to meet the specifications given in Section 5 of the Operation Manual Section 2 OPTION INSTALLATION MODIFICATION Section 2 contains necessary information for modifying the 4278A s options Section 3 REPLACABLE ASSEMBLY LIST Section 3 provides a list of the assemblies that can be replaced at the assembly repair level Section 4 ASSEMBLY LEVEL TROUBLESHOOTING Section 4 provides the information necessary for assembly level repair of the 4278A Appendix A MANUAL CHANGES Appendix A includes information for modifying this manual for instruments manufactured after the printing date of this manual Agilent 4278A 1 kHz 1 MHz CAPACITANCE METER Maintenance Manual SERIAL NUMBERS This manual applies directly to inst
35. R SUPPLY ADJUSTMENTS 1 8 1 8 1 POWER SUPPLY SWITCHING FREQUENCY ADJUSTMENT 18 1 8 2 POWER SUPPLY OUTPUT VOLTAGE ADJUSTMENT 1 10 1 9 SIGNAL SOURCE ADJUSTMENT 1 12 1 10 1MHz TRANSDUCER ADJUSTMENTS 1 14 1 10 1 SECOND NULL AMPLIFIER OFFSET ADJUSTMENT 1 14 1 10 2 FIRST NULL AMPLIFIER RESONANCE FREQUENCY ADJUSTMENT 1 15 1 11 1kHz TRANSDUCER ADJUSTMENTS 1 16 1 11 1 TRANSDUCER OFFSET VOLTAGE ADJUSTMENT x 1 16 1 11 2 CURRENT CHANNEL AMPLIFIER OFFSET VOLTAGE ADJUSTMENT 1 17 1 11 83 VOLTAGE CHANNEL AMPLIFIER OFFSET VOLTAGE ADJUSTMENT 1 18 1 12 AUTO CALIBRATION 1 19 112 1 CALIBRATION SETUP 1 20 1 12 2 STANDARD DATA TABLE ENTRY 1 21 1 12 3 CALIBRATION METHOD 1 26 1 12 4 RETURNING THE EEPROM WRITE PROTECT JUMPER 1 32 SECTION 2 2 1 2 2 2 3 2 4 2 5 2 6 2 7 SECTION 3 3 1 3 2 3 3 3 4 SECTION 4 4 1 4 2 4 3 4 6 4 7 INSTALLING MODIFING OPTIONS INTRODUCTION OPTION INSTALLATION MODIFICATION ADDING 1MHz MEASUREMENT CAPABILITY TO OPTION 001 4278As ADDING 1kHz MEASUREMENT CAPABILITY TO OPTION 002 4278As OPTION 003 INSTALLATION OPTION 101 HP IB INTERFACE INSTALLATION OPTION 201 HANDLER INTERFACE INSTALLATION REPLACEABLE ASSEMBLIES INTRODUCTION REPLACEABLE ASSEMBLY LIST ORDERING INFORMATION DIRECT MAIL ORDERING ASSEMBLY LEVEL TROUBLESHOOTING INTRODUCTION SAFETY CONSIDERATIONS RECOMMENDED TEST EQUIPMENT AFTER SERVICE PRODUCT SAFETY CHECKS ASSEMBLY DESIGNAT
36. T This adjustment minimizes the DC offset voltage of the current to voltage Converter PROCEDURE 1 Set the 3478A s controls as follows FUNCTION DCV RANGE AUTO 2 Connect the LO lead of the 3478A to A4TP2 and the HI lead to A4TP1 as shown in Figure 1 8 Banana Plug to Alligator HP4278A 6 Clip Cable _ LO lead HP3478A ongona Figure 1 8 1kHz Transducer Adjustment Setup 3 Set the 4278A s controls as follows FREQUENCY 1kHz RANGE 100pF 4 Adjust A4R1 I V OFFSET ADJ until the voltage displayed on the 3478A is OV 3mV AATPS Figure 1 9 1kHz Transducer Adjustment Locations NOTE Continue on to the next adjustment without resetting the 4278A and 3478A 1 11 2 CURRENT CHANNEL AMPLIFIER OFFSET VOLTAGE ADJUSTMENT This adjustment minimizes the DC offset voltage of the current channel output PROCEDURE 4 Connect the LO lead of the 3478A to A4TP7 and the HI lead to A4TP3 as shown in Figure 1 8 2 Adjust A4R2 ICH OFFSET ADJ until the voltage displayed on the 3478A is OV 5mV NOTE Continue on to the next adjustment without resetting the 4278A and 3478 1 11 3 VOLTAGE CHANNEL AMPLIFIER OFFSET VOLTAGE ADJUSTMENT This adjustment minimizes the DC offset voltage of the voltage channel output PROCEDURE 1 Connect the LO lead of the 3478A to A4TP7 and the HI lead to A4TP5 as Figure 1 8 2 Adjust A4R8 VCH OFFSET ADJ until the voltage displayed on
37. USTMENT 1 18 1 12 AUTO CALIBRATION 1 19 1 12 1 CALIBRATION SETUP 1 20 1 12 2 STANDARD DATA TABLE ENTRY 1 21 1 12 3 CALIBRATION METHOD 1 26 1 12 4 RETURNING THE EEPROM WRITE PROTECT JUMPER 1 32 SECTION 1 ADJUSTMENTS 1 1 INTRODUCTION This section describes the adjustments required to ensure that the HP 4278A is within its published specifications after it has been repaired These adjustments should be performed along with periodic maintenance to keep the HP 4278A in optimum operating condition The recommended calibration cycle is six months If proper performance cannot be achieved after calibration refer to the troubleshooting procedures in Section 4 NOTE To ensure proper results and correct instrument operation Hewlett Packard sug gests a 30 minute warm up and stabilization period before performing any of the following adjustments 1 2 SAFETY CONSIDERATIONS This manual contains NOTEs CAUTIONs and WARNINGs which must be followed to ensure the safety of the operator and to keep the instrument in a safe and serviceable condition The adjustments covered in this section must be performed by qualified service personnel ANY INTERRUPTION OF THE PROTECTIVE GROUND CONDUCTOR INSIDE OR OUTSIDE THE INSTRUMENT OR DISCONNECTION OF THE PROTECTIVE GROUND TERMINAL CAN MAKE THE INSTRUMENT DANGEROUS INTENTION AL INTERRUPTION OF THE PROTECTIVE GROUND SYSTEM FOR ANY REASON IS PROHIBITED The removal or opening of covers for adjust
38. able Tie 1400 1361 NOTE The letters in parentheses are the letters on the wire markers PROCEDURE 1 Remove the top cover and the right hand side top shield plate Refer to para graph 1 7 for instructions on removing the top cover and the top shield plate 2 Connect the four coaxial cables listed in the required parts list to the four con nectors on the 1MHz Transducer Board Assembly see Figure 2 2 NOTE The letters on the cable markers should match the letters marked beside the con nectors on the board NOTE Use the special extractor tool HP P N 8710 1754 to prevent damaging the coaxial cables and connectors when removing them from the board 2 3 10 Figure 2 2 1MHz Transducer Board Install the 1MHz Transducer Board into the slot see Figure 2 1 Then place the coaxial cables on the saddle edge see Figure 2 1 for the location of the saddle edge Remove the A5 Switching Matrix Phase Detector board from 4278A and connect coaxial connectors and 1 from the board to connectors and I on the A5 board Reinstall the A5 board then place the coaxial cables on the saddle edge see Figure 2 1 to locate the saddie edge Remove the front panel assembly from the 4278A Refer to paragraph 4 7 4 for instructions on how to remove the front panel Connect coaxial cables B and D from the A3 board to connectors B and D on the A8 board Cut
39. age refer to INSTRUMENTS COVERED BY MANUAL in SECTION 5 of the Operation Manual Table A Manual Changes by Serial Number Serial Prefix Make Manual Changes or Number A 1 REGIONAL SALES AND SUPPORT OFFICES For more information about Agilent Technologies test and measurement products applications services and for a current sales office listing visit our web site http www agilent com find tmdir You can also contact one of the following centers and ask for a test and measurement sales representative 11 29 99 United States fax 61 3 9272 0749 Agilent Technologies tel 0 800 738 378 New Zealand Test and Measurement Call Center fax 64 4 802 6881 P O Box 4026 Englewood CO 80155 4026 Asia Pacific tel 1 800 452 4844 Agilent Technologies 24 F Cityplaza One 1111 King s Road Canada Taikoo Shing Hong Kong Agilent Technologies Canada Inc tel 852 3197 7777 5150 Spectrum Way fax 852 2506 9284 Mississauga Ontario L4W 561 tel 1 877 894 4414 Europe Agilent Technologies Test amp Measurement European Marketing Organization P O Box 999 1180 AZ Amstelveen The Netherlands tel 31 20 547 9999 Japan Agilent Technologies Japan Ltd Call Center 9 1 Takakura Cho Hachioji Shi Tokyo 192 8510 Japan tel 81 426 56 7832 fax 81 426 56 7840 Latin America Agilent Technologies Latin American Region Headquarters 5200 Blue Lagoon Drive Suite 950 Miami Florida 33126 U S
40. ain access to the A1 assembly re move the top shield plate on which the WARNING message is printed CAPACITORS ON THE A1 BOARD REMAIN CHARGED WITH HAZARDOUS VOLT AGES FOR A PERIOD OF TIME AFTER THE INSTRUMENT IS TURNED OFF OR AFTER THE POWER CABLE IS DISCONNECTED ALLOW AT LEAST ONE MINUTE FOR THE CAPACITORS TO DISCHARGE AFTER THE INSTRUMENT IS TURNED OFF OR THE POWER CABLE IS DISCONNECTED 2 Slide the top shield plate towards the front and lift it off 3 Lift the black and the brown board extractors at the top corners of the A1 as sembly as shown in Figure 4 1 Figure 4 1 A1 Assembly Removal 4 Disconnect the cable connected to the rear panel from the A1 assembly 4 7 3 A2 A3 A4 A5 A6 A7 A20 OR A30 ASSEMBLY REMOVAL 1 Loosen the five screws that secure the right hand side top shield plate You don t have to remove the screws NOTE There are two top shield plates In order to access A2 AS A4 A5 A6 A7 A20 or A30 assembly remove the top shield plate on which the WARNING message is NOT printed 2 Slide the top shield plate towards the front and lift it off 4 5 3 Lift the extractors at top corners of the board assembly that you want to remove NOTE Use the special extractor tool to disconnect the coaxial cables from a board as sembly Refer to paragraph 4 6 4 7 4 FRONT PANEL DISASSEMBLY This paragraph shows how to remove the front panel assembly from the 4278A In order to remove the A8
41. andard into the STAN DARD DATA TABLE The calibration values for 1kHz and 1MHz are entered independently You can also enter a standards calibration values using a memory card For example if you calibrate multiple 4278As using the same standard you don t have to key in the standard s calibration values for each STANDARD DATA TABLE you only need to press the front panel LOAD key to load the calibration values from the memory card NOTE Prepare a memory card to use exclusively for storing a standard s calibration values The following procedure consists of three paragraphs Paragraphs 1 and 2 gives the procedures for entering the standard s calibration values into the 1kHz and 1MHz STAN DARD DATA TABLE respectively Paragraph 3 tells how to use the memory card for storing the calibration values 1 21 1 1kHz STANDARD DATA TABLE ENTRY The following describes how to enter the standard s calibration values into the 1kHz STAN DARD DATA TABLE Skip to 2 if your 4278A does not have the 1kHz measurement function PROCEDURE 1 Press the 1kHz DATA softkey 2 Use the numeric ENTRY and ENTER keys to enter your standard s calibration values into the STANDARD DATA TABLE NOTE If you use the HP 16380A capacitors as the calibration standards use the calibra ted capacitance given in the calibration data sheet supplied with the 16380A The dissipation factor for the 100pF and 1000pF standard capacitors can be regarded
42. ange 16pF OSC Level 1Vrms A2 Signal Source Phase Qvo GvooG 0 Q Detector A D gt Converter Figure 4 10 Second Null Amplifier The 1Vrms signal from the A2 board is input directly to the A5 board as ey ey is phase detected on the A5 board and the phase detected e is converted to a digital value on the A6 board The second null amplifier converts the noise current flowing through the first null amplifier is converted to voltage e e is phase detected on the A5 board and the phase detected e is converted to a digital value on the A6 board The digital values of e and e are used to calculate the ratio e ey and the result is displayed This test will pass when the calculated result is within the limit listed as follows Limit Values RESULT lt 0 0003 4 23 A4 1kHz TRD Test This test checks the operation of the transducer circuit on the A4 board Perform this test after you confirm the A2 A5 and A6 boards used in this test are working properly The 4278A s setup in this test is different from the typical measurement setup in order to check the 1kHz transducer circuit as shown in the Figure 4 11 There are two attenuators on the A4 board one for the I channel and one for the V channel Each attenuator has two settings ON and OFF The ON setting of the attenuator Low Gain is used when the OSC level is from 0 4Vrms to 1 0Vrms and the OFF setting of the attenuator High Gain is used when the OSC
43. ate the setting error ratio of the C offset current divider and then the result is displayed This test will pass when the calculated result is within the limits as follows RESULT 0 5 4 19 A3 1MHz TRD Range Div Test This test checks the ranging current divider used for 1MHz measurements on the A3 board Perform this test after you confirm the A2 A5 and A6 boards used in this test are working properly In this test the 4278A s setup is different from the typical setup in order to check the ranging current divider as shown in the Figure 4 8 Phase Evo CvaqGio 190 Detector Ranging i lt Converter Current Divider Figure 4 8 Ranging Current Divider When this test is performed the internal test current signal E gy 1 is applied to the ranging current divider which is set to the 16pF measurement range and the divided current signal is converted to the voltage e by the second null amplifier The converted e is phase detected on the A5 board and the detected e is con verted to a digital value on the A6 board The internal test voltage signal E V is input directly to the AS board as ey ey is phase detected on the A5 board and the detected e is converted to a digital value on the A6 board Then the e and e digital converted values are used to calculate the ratio e e The 4278A sets the ranging current divider to the 8pF measurement range and repeats the preceding procedure again to ca
44. ation modification procedures Information on how to order the parts required to install or modify an Option is described in paragraph 3 3 The adjustments required in the Option installation procedure must be performed to maintain the performance of the 4278A The adjustment procedures are described in Section 1 2 2 OPTION INSTALLATION MODIFICATION The Options available for the 4278A all of which are field installable are listed in Table 2 1 Table 2 1 lists the option numbers gives a description of the option and lists the paragraph number which describes the modification procedure for each option Figure 2 1 shows the location of the board assemblies to be installed or modified and the saddle edge Table 2 1 List of 4278A Options Option Number Description Modification Installation Procedure 001 1kHz Test Frequency Only Paragraph 2 3 1MHz Test Frequency Only Paragraph 2 4 1 Frequency Shift Paragraph 2 5 HP IB Interface Paragraph 2 6 Handler Interface Paragraph 2 7 2 1 po th Figure 2 1 Board Locations 2 2 2 3 ADDING 1MHz MEASUREMENT CAPABILITY TO OPTION 001 4278As The following procedure describes how to modify an HP 4278A with Option 001 to add 1MHz measurement capability REQUIRED PARTS 1MHz Transducer Board Assembly 04278 66503 Coaxial Cable Assembly B 04278 61606 Coaxial Cable Assembly D 04278 61604 Coaxial Cable Assembly H 04278 61612 Coaxial Cable Assembly I 04278 61613 C
45. d 100pF capacitor a few seconds 16048D 2m test lead a few seconds OPEN reference 16048D 2m test lead about 20 sec SHORT reference 16048D 2m test lead 6 Confirm that 1MHz Calibration is Complete is displayed 1 31 1 12 4 RETURNING THE EEPROM WRITE PROTECT JUMPER Calibration is now complete so perform the following steps to write protect the 4278A s EEPROM 1 Press the exit CAL softkey to exit the Calibration Mode 2 Turn the 4278A off and remove the A7 board assembly 3 Restore the 4278A s EEPROM write protect jumper A7W2 to its Normal position left hand side the location of the jumper A7W2 is shown in Figure 1 10 4 Install the A7 board assembly 5 Replace the shield plate and the top cover 1 32 2 5 2 6 2 7 SECTION 2 INSTALLING MODIFYING OPTIONS INTRODUCTION 2 1 OPTION INSTALLATION MODIFICATION 2 1 ADDING 1MHz MEASUREMENT CAPABILITY TO OPTION 001 4278As 2 3 ADDING 1kHz MEASUREMENT CAPABILITY TO OPTION 002 4278As 2 5 OPTION 003 INSTALLATION 2 7 OPTION 101 HP IB INTERFACE INSTALLATION 2 9 OPTION 201 HANDLER INTERFACE INSTALLATION 2 11 SECTION 2 INSTALLING MODIFYING OPTIONS 2 1 INTRODUCTION This section contains information about adding Options for which the 4278A was not initially equipped and for modifying existing Options Most of the procedures in this section include a list of Required Parts and the install
46. d capacitors use the calibra ted capacitance given for the 1pF 10pF and 100pF standard capacitors given for 1kHz as the calibration values for 1MHz For the 1000pF standard capacitor multiply the value for 1kHz by 1 0003 Refer to the 16380A Data Sheet For the dissipation factor of the 1pF 10pF and 100pF standard capacitors use a value of zero and for the 1000pF standard capacitor use a value of 0 00004 3 Confirm that the standard s calibration values are correctly entered into the 1MHz STANDARD DATA TABLE Refer Figure 1 13 IMHz STANDARD DATA TABLE MEMORY STANDARD C D STORE 1pF 0 999970pF 000000 10pF 0 999920pF 000000 100pF 099 9960pF 000000 1000pF 1000 280pF 000040 Figure 1 13 1MHz STANDARD DATA TABLE Example 4 Press the exit TABLE softkey 1 24 3 USING THE MEMORY CARD FOR THE STANDARDS CALIBRATION VALUES The following describes how to use the memory card to store or load a standards calibra tion values The standards calibration values entered into the STANDARD DATA TABLE can be loaded from a memory The calibration values for 1kHz and 1MHz are stored in dependently Both the 1kHz and 1MHz data are loaded when you press the LOAD key Press the LOAD key while in the CALIBRATION MENU page because the calibration values are load only from this menu If you are not using a memory card go to paragraph 1 12 3 HOW TO STORE THE STANDARDS CALIBRATION VALUES PROCEDURE 1
47. displayed 1 28 2 1MHz CALIBRATION This paragraph describes 1MHz calibration using the calibration values in the STANDARD DATA TABLE Skip this paragraph if your 4278A does not have the 1MHz measurement function Do Not turn off the 4278 while you are performing the following procedure if you do the calibration data will be lost PROCEDURE 1 Press the 1MHz CAL softkey then the display as shown the Figure 1 15 is displayed 1MHz CALIBRATION Connect 10pF to UNKNOWN Term Set up then press trigger Figure 1 15 First Message at 1MHz CAL 2 Connect 10pF standard capacitor to the UNKNOWN terminals as instructed by the displayed message 3 Press the TRIGGER key and wait NOTE The following figures show the 4278A s transition from the time you press the TRIGGER key until the next measurement will be available Display1 1MHz CALIBRATION Connect 10pF to UNKNOWN Term Calibration in progress Display2 1MHz CALIBRATION gt Connect 1pF to UNKNOWN Term Calibration in progress Display3 1MHz CALIBRATION Connect 1pF to UNKNOWN Term Set up then press trigger Display 1 As soon as the 4278A starts to measure the 10pF standard capacitor Calibration in progress is displayed on the SYSTEM MESSAGE LINE as shown in the Dis play 1 While this message is displayed the 4278A is measuring the 10pF stan dard capacitor Display 2 After the analog m
48. easurement is complete Connect 1pF to UNKNOWN Term is displayed as shown in the Display2 This message means that you may discon nect the 10pF capacitor and connect the 1pF capacitor While this message is displayed the 4278A is writing calibration data to the EEPROM Display 3 After the 4278A has completed writing the calibration data to EEPROM Set up then press trigger is displayed on the SYSTEM MESSAGE LINE as shown in Display 3 When this message is displayed the next measurement is available 4 Disconnect the 10pF standard capacitor after the Display 3 is displayed and connect the 1pF standard capacitor 5 Repeat steps 3 through 4 according to the connection order listed in Table 1 5 NOTE You can perform the calibration s procedure according to the display only NOTE The Processing Time shown in Table 1 5 is the approximate time from when you press the TRIGGER key until the next measurement will be available Table 1 5 1MHz Connection Order Connection Order Standard Connected 10pF capacitor about 40 sec pF capacitor about 20 sec a few seconds 100pF capacitor a few seconds 1000pF capacitor a few seconds OPEN reference about 10 sec SHORT reference 100pF capacitor a few seconds 16048A 1m test lead OPEN reference a few seconds 16048A 1m test lead SHORT reference about 20 sec 16048A 1m test lea
49. he following three types Power on self test Softkey selected self test and Hardware selected bit switch selected self test 1 Power on self test Every time the 4278A is turned on it performs a power on self test during the power on sequence When the power on sequence halts because of a failure the LED indicators on the A7 board indicate which power on sequence step was being performed at the time of the failure Use this information as a troubleshooting aid to localize the prob lem The following chart shows the power on sequence and the LED indication pat tern LED numbers are designated by their top to bottom position on the A7 board LED Pattern 1 ON 0 OFF Upper Under 123 P m 67 8 Task Clears memory card read write flip flop Turns off memory card power supply LED test LED test LED test LED test LED test LED test LED test LED test LED test LED test initializes LCD controller Initializes timer on A7 Initializes timer on A90 Initializes A90 Initializes timers for A D Converters Initializes HP IB chip on A20 Initializes PIA chip on A30 5 Clears all interrupt signal RAM read write test Displays Copyright message ROM check sum test _ EEPROM 0 check sum test EEPROM 1 check sum test Analog test 1kHz Analog test 1MHz Starts measurements dO20 00 00000000 xx
50. he resistance from the instrument enclosure to the power cord s ground pin The resistance must be less than 0 52 Flex the power cord while making this measurement to determine if any intermittent discontinuities exist Check the GUARD terminal on front panel using the procedure outlined in step 2 Disconnect the 4278A s power plug from the power source Turn on the power switch Tie the line and neutral pins of the power connector together and check the resistance between them and the instrument s enclosure The mini mum acceptable resistance is 2MQ Find and replace any component which causes the instrument to fail this test Verify that the correct fuse is installed 4 5 ASSEMBLY DESIGNATIONS Assemblies such as printed circuit boards are assigned numbers in sequence A1 A2 etc as shown in Table 4 1 Assembly locations are given in Section 3 Table 4 1 Assembly Identification Assembly Assembly Name Power Supply Board Assembly Signal Source Board Assembly 1MHz Transducer Board Assembly not installed on option 001 unit 1kHz Transducer Board Assembly not installed on option 002 unit Switching Matrix Phase Detector Board Assembly A D Converter Board Assembly Digital Control Board Assembly Input Switch Board Assembly Keyboard Assembly Memory Card Socket Board Assembly Motherboard Assembly DC AC Converter Board Assembly 101 HP IB Board Assembly option 101 unit only 201 Handler Interface Boa
51. he top cover retaining screw located at the back of the top cover 3 Slide the top cover towards the rear and lift it off 4 Loosen the five screws that secure the right hand side top shield plate You don t have to remove the screws DO NOT REMOVE THE LEFT HAND SIDE TOP SHIELD PLATE ON WHICH WARN ING MESSAGE IS PRINTED 5 Slide the top shield plate towards the front and lift it off TO PROTECT AGAINST POSSIBLE ELECTRICAL SHOCK USE INSULATED TOOLS TO MAKE ALL ADJUSTMENTS Oscilloscope Divider Probe RMS Voltmeter Test Cable Digital Voltmeter Test Lead Standard Capacitor Standard Resistor OPEN SHORT Reference Test Leads Extender Board Tool Table 1 1 Recommended Test Equipment Qty Recommended Model HP 1740A Critical Specification Band Width gt 10MHz Range 10mV div min Voltage Accuracy lt 3 10 1 1MQ Frequency 1kHz to 1MHz Accuracy lt 1 BNC m to BNC m 30cm Range DC 0 1 1 0 and 30V Sensitivity 0 1mV min Dual Banana Plug to Alligator Clip Nominal C 1pF 10pF 100pF 1nF 10nF 100nF 1uF Calibrated at 1kHz and 1MHz Four Terminal Pair Nominal R 10 Calibrated at 1kHz supplied with 0Q reference Four Terminal Pair Four Terminal Pair Length 1m and 2m Four Terminal Pair For Digital Board Coaxial Cable Extractor HP 10040A HP 3400A PN 8120 1838 HP 3478A HP 11002A HP 16380A HP 16380C P O HP 16074A P O HP 16074A HP
52. indicators on the A9 board The A91 assembly is the LCD module This includes the digital control and driver circuits for the LCD and the LCD panel 4 12 ANALOG SECTION BLOCK DIAGRAM A2 SIGNAL SOURCE er m DE AE SWITCHING MATRIX PHASE DETECTOR A6 A D CONVERTER T P d _ Mutti Slope amp D Converter 8MH2 Xtol OSC i 1 1 1 rr una mo oam no oo Power Ampl Source Resistors EJ L 8 08MHz on option 003 OSC Level ARAN mn 100 DM MEE 8 A3 MHz TRANSDUCER Divider gt Multi Siepe 500 Divioer 33 offset Ld A D Converter 2 Current Divider 1 am Br SRG LOAD IMLOC HJ hr AA Multi Siope DC Offser Concel A D Converter I m olio s Multi Slope I Relay o gt amp D Converter 1 Control 4 j a i Loca 1 Power Detection i 1 Reguloror IMLOC 90 Phase 1 t Geniercior A4 KHz TRANSDUCER J3 i a j o o 1 bid r vor pal ES it 9 deu t my IX IM o gt JB Figure 4 6 Analog Circuit Block Diagram 4 13 4 9 TROUBLESHOOTING Paragraph 4 9 1 describes the 4278A s Self Tests Paragraph 4 9 2 describes the trouble shooting procedure of using flow charts to isolate the faulty board 4 9 1 SELF TEST The 4278A s self tests can be categorized into t
53. ircuit Troubleshooting Procedure 4 37 START Turn off and then remove the A20 and A30 boards Set all bits of A7S3 to OFF Turn on the 42784 is the trouble cured Turn off and Perform the bit switch selectable self test number 5 referring to para graph 4 9 1 3 NOTE Be sure and restore the bit switch after troubleshooting is compiete if you change bit switch A7S3 YES Reinstall the A20 board and set only bit of A7S3 1 to ON The trouble is in the A20 or A30 buard NOTE Be sure and restore the bit switch after troubleshooting is complete if you change bit switch 753 Does the LCD repeatediy turned on and off Turn off and repiace the A7 board Turn off and check the fuse on the A9 board Their location is given in Table 3 5 2 2 15 the fuse blown Replace the fuse Replace the A90 board then turn on again If the trouble isn t cured yet replace the A91 board Figure 4 17 Digital Circuit Troubleshooting Procedure Turn on the 42784 Is the trouble cured Turn off and replace the A20 board YES Turn off and remove the A20 board Reinstall A30 board and set only bit of A7S3 3 to ON NOTE Be sure and restore the bit switch after troubleshooting is complete if you change bit switch 753 Turn on the 4278A If the yes trouble is not cured turn off and check the fuse blown is the fuse blown Rep
54. lace the A30 board Replace the blown fuse 4 39 Table 4 5 gives troubleshooting information based on Performance Test failures Table 4 5 When the Performance Tests Fail 1 2 Test Failed Checked Board Verification and Coaxial Cable Method Test frequency accuracy A2 A8 Check the test signal at A2TP5 EOSC If the test signal is ap proximately 1Vrms approximately 2 8Vpp but not present at A2TP5 replace the A2 board otherwise check the coaxial cable labeled G and the 8 board A2 A8 G Check the test signal at A2TP5 EOSC If the test signal is ap otherwise check the coaxial cable labeled and the A8 board 1kHz capacitance accuracy A8 A C E Check the coaxial cable labeled A C and E and the A8 board proximately 1Vrms approximately 2 8Vpp but is not present at A2TP5 replace the A2 board 1MHz capacitance accuracy 8 D Check the coaxial cable labeled B D F and I and the A8 board Test signal level accuracy If the 4278A fails the 1kHz fluc tuation check only replace the A4 board If it fails only the 1MHz fluctuation check only replace the A3 board If both 1kHz and 1MHz fluctuation checks fail replace the A5 board 1kHz 1MHz fluctuation A4 AS Perform the test using another memory card If the test still fails replace the A10 board Store and load function 4 41 Table 4 5 When the Perf
55. lculate the ratio e e Then using the two calculated ratios the setting error ratio of the ranging current divider is calculated and that result is displayed RESULT 1 Similarly by changing the setting of the Range Current Divider to each range 32pF range for RESULT 2 64pF range for RESULT 3 128pF range for RESULT 4 256pF range for RESULT 5 512pF range for RESULT 6 and 1024pF range for RESULT 7 the ratio e e for each range is calculated By using the calculated ratio for each range and the ratio of 16pF range setting as a reference the setting errors of the ranging current divider are calculated and the results are displayed 4 20 This test will pass when all results are within the following listed limits Limit Values RESULT 1 0 02 RESULT 2 lt 0 02 RESULT 3 lt 0 03 RESULT 4 lt 0 07 RESULT 5 lt 0 1 RESULT 6 lt 02 RESULT 7 lt 0 4 4 21 1MHz TRD 1st Null Amp Test This test checks the first null amplifier on the A3 board used for 1MHz measure ments This test is also used for performing the adjustment given in paragraph 1 10 2 Perform this test after you confirm that the A2 A5 and A6 boards used in this test are working properly In this test the 4278A s setup is different from the typical measurement setup in order to check the first null amplifier as shown in the Figure 4 9 Phase Qvo von o 90 Detector Converter Figure 4 9 First Null Amplifier When this test is
56. level is from 0 1Vrms to 0 3Vrms This test uses both attenuator settings to check the transducer circuit Phase Qvo Pvsgkio iso Detector Converter Figure 4 11 1kHz Transducer During this test the internal test voltage signal E V is applied to the differential amplifier and the output signal from of the differential amplifier passes through the attenuator ON and is input to the A5 board as e e is phase detected on the A5 board and the phase detected e is converted to a digital value on the A6 board The internal test current E l is applied to the l V converter and converted The output from the I V converter passes through the attenuator ON and is input to the 5 board as e e is phase detected on the 5 board and the detected e is converted to a digital value on the board The amplitude values ABS l of e the ratio ABS I V of e and e and the phase difference TANGENT of e and e are calculated using both e and e digital values The calculated values are dis played The 4278A changes the attenuator s setting OFF and repeats the preced ing procedure 4 24 This test will pass when the calculated results are within the limits listed as follows Limit Values OSC LVL 1 0V low gain 22100 lt 0 96420 lt 0 03842 lt ABS I ABS I V TANGENT OSC LVL 0 3V high gain 73800 lt 0 96420 lt 0 03842 lt ABS I ABS I V TANGENT 4 25 IA HA
57. loded view of the 4278A Tables 3 2 through 3 4 lists the internal cable assemblies of the 4278A The follow ing information for each cable assembly is included a The Hewlett Packard part number b Quantity in the 4278A c A description of the assembly 3 3 ORDERING INFORMATION When ordering a replacement assembly listed in this section specify the HP part number the quantity required and send your order to the nearest HP Sales Office When ordering an assembly not listed in this section state the full instrument model number and serial number describe the function of the assembly and give the quantity required Send your order to the nearest Hewlett Packard Sales Office 3 4 DIRECT MAIL ORDERING HP supplies parts through the direct mail order system within the United States The ad vantages of using the direct mail order system are a Direct ordering and shipment from the HP Parts Center in Mountain View California b No maximum or minimum on any mail order there is a minimum order for parts ordered through a local HP Office if the orders require billing and invoicing c Prepaid shipping there is a small handling charge for each order d No invoices a check or money order must accompany each other Mail order forms and specific ordering information are available through your local HP office Addresses and telephone numbers are listed in the back of this manual Table 3 1 Replaceable Assembly List 1 3
58. ment or removal of parts other than those which are accessible by hand will expose circuits containing dangerous voltages Remember that even though you may have shut the instrument off and unplugged it the capacitors in the 4278A can remained charged for a few minutes 1 1 THE ADJUSTMENTS DESCRIBED IN THIS SECTION ARE PERFORMED WITH POWER APPLIED AND THE PROTECTIVE COVERS REMOVED DANGEROUS VOLTAGE LEVELS EXIST AT MANY POINTS AND CAN RESULT IN SERIOUS PERSONAL INJURY OR DEATH IF YOU COME INTO CONTACT WITH THEM 1 3 TEST EQUIPMENT Table 1 1 lists the test equipment required to perform the adjustments described in this section Use only calibrated test equipment when adjusting the 4278A If the recommended test equipment is not available equipment whose specifications are equal to or surpass those of the recommended test equipment may be used 1 4 ADJUSTABLE COMPONENTS Table 1 2 lists the 4278A s adjustable components lists the name of the adjustment related to each component and gives a brief description of each adjustment 1 5 ADJUSTMENT INTERACTION Some of the 4278A adjustments are interactive If you repair or replace an HP 4278A as sembly be sure to perform the related adjustment s in the sequence given Table 1 3 lists the adjustments required for each assembly repaired or replaced Ignoring or changing the adjustment sequence will make it impossible to obtain optimum performance 1 6 ADJUSTMENT LOCATIONS Figure 1
59. method using the standard s calibration val ues stored in the 1kHz STANDARD DATA TABLE Skip this paragraph if your 4278A does not have the 1kHz measurement function Do Not turn off the 4278A while you are performing the following procedures if you do the calibration data will be lost PROCEDURE 1 Press the 1kHz CAL softkey the display will appear as shown in the Figure 1 14 1kHz CALIBRATION Connect 100pF to the UNKNOWN Term Set up then press trigger Figure 1 14 First Message at 1kHz CAL 2 Connect the 100pF standard capacitor to the UNKNOWN terminals as instructed by the display message 1 26 3 Press the TRIGGER key and wait NOTE The following figures show the 4278A s transition from the time you press the TRIGGER key until the next measurement will be available Display1 1kHz CALIBRATION Connect 100pF to UNKNOWN Term Calibration in progress Display2 1kHz CALIBRATION Connect 1000pF to UNKNOWN Term Calibration in progress Display3 1kHz CALIBRATION Connect 1000pF to UNKNOWN Term Set up then press trigger Display 1 As soon as the 4278A starts to measure the 100pF standard capacitor Calibration in progress is displayed on the SYSTEM MESSAGE LINE as shown in the Dis play 1 While this message is displayed the 4278A is measuring the 100pF stan dard capacitor Display 2 After the analog measurement is complete Connect 1000pF to UNKNOWN
60. nd check the coaxial cable labeled 1 Is this cabie no trouble NO Replace the cable YES YES Perform self test number 7 Does the 4278A pass this test YES Perform self tests number 4 Is the trouble only during YES 1kHz power on self test NOTE NO Self test number 4 is per formed connecting the OPEN to UNKNOWN terminal NO Perform the adjustment Turn off and replace the 5 described in paragraph 1 11 board 2 then repeat this test Perform self test number 5 Does the 4278A pass this test Perform self test number 6 Does the 4278A pass this test is the trouble only during 1MHz power on self test Turn off and replace the A5 board Turn off and replace the A5 board Turn off and replace the A4 board YES Does the 42784 pass this YES test Turn off and check the coaxial cable labeled F Is Replace the board this cable nc trouble Replace the cable Check the coaxial cables iabeled A C and E and the 8 board Tum off and check the coaxial cables labeled B D F Hand I and the AB board Perform self test number 2 YES Does the 4278A pass this test NO Tum off and check the coaxial cable labeled I is this cable no throuble Replace the A3 board Replace the A3 board Replace the cable Figure 4 16 Analog C
61. nuts screws washers Use the washers listed in the required parts list in place of the washers included with the HP IB cable assembly to mount the HP IB Cable Assembly on the HP IB 2 Remove the top cover and the right hand side shield plate 3 Install the 101 HP IB Interface board in the A20 slot as shown in Figure 2 1 2 9 4 Remove the blank panel installed over the second slot from the left on the rear panel and install the HP IB Panel as shown in Figure 2 6 Figure 2 6 Option 101 Set Up 5 Connect the HP IB Assembly s female connector to the male connector on the HP IB Interface board A20J1 as shown in Figure 2 6 6 Remove the A7 board and set bits O and 1 of switch 753 A7S3 1 and A7S3 2 as shown in Figure 2 7 A7 Digital Control Board Component Side Figure 2 7 A7S3 Setting for Option 101 NOTE Refer to the paragraph 4 8 for more details on the switch bit patterns 7 Reinstall the A7 board 8 Perform the adjustments described in paragraph 1 8 2 7 OPTION 201 HANDLER INTERFACE INSTALLATION The following procedure describes how to install Option 201 Handler Interface in the 4278A REQUIRED PARTS 201 Handler Interface Board Assembly Cable Assembly I F Panel F Screw SCR M3 L 10 P H Nut NUT HEX W LOCKER Part Number Qty 04278 66530 04278 61622 04278 00211 0515 1551 0535 0031 PROCEDURE 1 Mount the I F Cable Assembly on
62. oducing additional hazards do not install substitute parts or perform unauthorized modifications to the instrument Return the instrument to a Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained Dangerous Procedure Warnings Warnings such as the example below precede potentially dangerous procedures throughout this manual Instructions contained in the warnings must be followed Warning Dangerous voltages capable of causing death are present in this instrument Use extreme caution when handling testing and adjusting Y this instrument SAFETY SYMBOLS General Definitions of Safety Symbols Used On Equipment or In Manuals A WARNING CAUTION Instruction manual symbol the product will be marked with this symbol when it is necessary for the user to refer to the instruction manual in order to protect against damage to the instrument Indicates dangerous voltage terminals fed from the interior by voltage exceeding 1000 volts must be so marked Protective conductor terminal For protection against electri cal shock in case of a fault Used with field wiring terminals to indicate the terminal which must be connected to ground before operating equipment Low noise or noiseless clean ground earth terminal Used for a signal common as well as providing protection against elec trical shock in case of fault A terminal marked with this symbol must
63. ormance Tests Fail 2 2 HP IB interface function Handler interface function 4 42 Check the HP IB connector on the rear panel and the flatcable connected to it If the trouble is not on the connector and cable replace the A20 board Check the handler interface con nector on the rear panel and the flatcable connected to it If the trouble is not on the connector and cable replace the A30 board Turn off then check the wire connecting the A13 board and A91 board Is the wire broken Are the neon lights on the A13 YES board lit Roplace this wire START Replace the A13 board Turn off then check the wire YES connecting the A13 board and A91 board is the wire broken Does the 4278A pass this test Replace the A91 board Figure 4 18 The Back Light On The Display Is Not Lighting 4 43 APPENDICES APPENDIX A MANUAL CHANGES A 1 MANUAL CHANGES APPENDIX A Appendix A contains information for 4278A s to which the content of this manual does not directly apply To adapt this manual to your instrument refer to Table A and make all of the manual chang es listed opposite of the serial number group in which the serial number of your 4278A belongs If your instrument serial number is not listed on the title page of this manual or in Table A it may be documented in the yellow MANUAL CHANGES supplement For additional informa tion on serial number cover
64. performed the internal test voltage E V is applied to the first null amplifier The output current signal from the first null amplifier is checked as follows The output current signal is converted into voltage signal e by the second null amplifier e is phase detected on the 5 board and the detected e is converted to a digital value on the A6 board The internal test voltage E s V is input directly to the 5 board as ev e is phase detected on the A5 board and the detected e is converted to a digital value on the A6 board The digital values of e and e are used to calculate the ratio e ey which is then displayed This test will pass when the calculated result is within the limit listed as follows Limit Values 0 00 lt RESULT lt 0 4 4 22 A3 1MHz TRD 2nd Null Amp Test This test checks the second null amplifier on the A3 board which is used for making 1MHz measurements This test is also used for performing the adjustment given in paragraph 1 10 1 Perform this test after you confirm the A2 AS and A6 used in this test are working properly This test must be performed while connect ing the OPEN standard to the UNKNOWN terminals or making connects between the and Hp terminals and between the Loy and Loo terminals by using the two BNC cable which are as short as possible The 4278A is setup as follows for this test Refer Figure 4 10 Measurement Frequency 1MHz normal mode Measurement R
65. ration service and repair of this instrument Failure to comply with these precautions or with specific WARNINGS elsewhere in this manual may impair the protection provided by the equipment In addition it violates safety standards of design manufacture and intended use of the instrument The Agilent Technologies assumes no liability for the customer s failure to comply with these requirements Ground The Instrument To avoid electric shock hazard the instrument chassis and cabinet must be connected to a safety earth ground by the supplied power cable with earth blade DO NOT Operate In An Explosive Atmosphere Do not operate the instrument in the presence of flammable gasses or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away From Live Circuits Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified maintenance personnel Do not replace components with the power cable connected Under certain conditions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power and discharge circuits before touching them DO NOT Service Or Adjust Alone Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT Substitute Parts Or Modify Instrument Because of the danger of intr
66. rd Assembly option 201 unit only Keyboard Display Control Board Assembly LCD Module Assembly 4 6 TOOLS AND FASTENERS The 4278A s internal coaxial cable assemblies use a new type of coaxial connector Use the special extractor tool PN 8710 1754 to disconnect these coaxial cables Using your fingers or pliers to disconnect these new coaxial connectors may damage them The 4278A s mechanical components are secured using metric screws Many screws in the 4278A may appear to be Phillips screws but they are in fact Pozidrive Use only Pozidrive screwdrivers when removing or tightening these screws to avoid damaging them 4 7 DISASSEMBLY The disassembly procedures are described in the following paragraphs First the top cover removal procedure is given Then the following paragraphs give information on removing each assembly from the instrument Refer to section 3 for the assembly locations 4 7 1 TOP COVER REMOVAL The following procedure should be performed to gain access to any of the assemblies 1 Remove the two plastic instrument feet located at the upper corners of the rear panel 2 Fully loosen the top cover retaining screw located at the rear of the top cover 3 Slide the top cover towards the rear and lift off 4 7 2 A1 ASSEMBLY REMOVAL 1 Loosen two screws that secure the left hand side top shield plate You don t have to remove the screws NOTE There are two top shield plates In order to g
67. ruments with serial number prefix 2713J and with firmware version 2 00 For additional important information about serial numbers read INSTRUMENT COVERED BY THIS MANUAL in Section 5 of the Operation Manual E Agilent Technologies Agilent Part No 04278 90100 Printed in JAPAN July 2000 Notice Hewlett Packard to Agilent Technologies Transition This manual may contain references to HP or Hewlett Packard Please note that H ewlett Packard s former test and measurement semiconductor products and chemical analysis businesses are now part of Agilent Technologies To reduce potential confusion the only change to product numbers and names has been in the company name prefix where a product name number was HP XXXX the current name number is now Agilent XXXX For example model number HP 8648 is now model number Agilent 8648 Contacting Agilent Sales and Service Offices The sales and service contact information in this manual may be out of date The latest service and contact information for your location can be found on the Web at http www agilent com find assist If you do not have access to the Internet contact your field engineer or the nearest sales and service office listed below In any correspondence or telephone conversation refer to your instrument by its model number and full serial number United States Latin America New Zealand tel 1 800 452 4844 tel 305 269 7500 tel 0 800 738 378 fax 1 800 829 4433
68. s all of the handler interface output pins 4 28 3 Self Tests Selected Using the Bit Switch Following self tests can be performed by setting the A7S3 bit switch Table 4 4 shows the A7S3 bit switch setting patterns and their description Table 4 4 Bit Switch Location and Patterns 1 2 A7 Digital Control Board Component Side Bit Switch Setting Description Number NEM HN ROM checksum display RAM read write test 2 The EEPROM for back up read write test By performing this test back up data compensation data etc in the EEPROM will be lost 4 29 Table 4 4 Bit Switch Location and Patterns 2 2 Bit Switch Setting Description Number The front panel keyboard test The code of the key pressed and its abbreviated name will be displayed EEPROM initialization This test will clear all the calibration data Do not perform this except when replacing the EEPROM The EEPROM calibration described in paragraph 1 12 must be per formed after this test is performed LCD test All dots on the LCD are repeatedly turned ON and OFF 4 30 4 9 2 TROUBLESHOOTING PROCEDURE This paragraph consists primarily of the following flow chart If you think the problem or trouble is in the 4278A use the this flow chart to identify which board is faulty START Turn on the 42784 Will be the 4278A turned on Does the 4278A pass the all of power on self test Does the 4278A pass the all of self tests b
69. the 3478A is OV 5mV 1 12 AUTO CALIBRATION The analog calibration data is stored in the 4278A s EEPROM must be updated when any adjustments are made to the 4278A The 4278A s calibration is performed by comparing a standards calibration values to the raw measurement values Auto calibration consists of four parts First in paragraph 1 12 1 you will set the 4278A s EEPROM write enable and operate the keys on the front panel to open the CAL menu page Second in paragraph 1 12 2 you will enter your standards calibration values into the table named STANDARD DATA TABLE in order to perform the calibration Third in paragraph 1 12 3 you will perform the calibration using your standards Fourth in paragraph 1 12 4 you will reset the 4278A s EEPROM write protect to save the calibration data memorized in EEPROM The auto calibration procedures are performed in paragraph number sequence NOTE Perform Auto Calibration when any adjustments have been made to the 4278A or when an EEPROM is initialized If your 4278A does not have the 1MHz measurement function skip paragraphs 1 12 2 2 and 1 12 3 2 If your 4278A does not have the 1kHz measurement function skip para graphs 1 12 2 1 and 1 12 3 1 The equipment used during auto calibration is as follows EQUIPMENT Standard Capacitor 1pF m P O HP 16380A Standard Capacitor 10pF P O HP 16380A Standard Capacitor 100pF P O HP 16380A Standard Capacitor 1nF P O HP 16380A Standard
70. the I F panel using the screws and nuts listed in the required parts list 2 Remove the top cover and the right hand side shield plate of the 4278A 3 Install the Handler Interface board into the A30 slot as shown in Figure 2 1 4 Remove the left most blank panel on the rear panel and install the I F panel place of the blank panel as shown in Figure 2 8 Figure 2 8 Option 201 Set Up 5 Connect the female connector of the I F cable assembly to the male connector A30J1 on the Handler Interface board as shown in Figure 2 8 6 Remove the A7 board and set bits 2 and 3 of switch A7S3 A7S3 3 and A7S3 4 as shown in Figure 2 9 A7 Digital Control Boord Component Side Figure 2 9 A7S3 Setting for Option 201 2 12 NOTE Refer to the paragraph 4 8 for more details on the switch bit patterns 7 Replace the A7 board 8 Perform the adjustments described in paragraph 1 8 2 13 3 1 3 2 3 4 SECTION 3 REPLACEABLE ASSEMBLIES INTRODUCTION 3 1 REPLACEABLE ASSEMBLY LIST 3 1 ORDERING INFORMATION 3 1 DIRECT MAIL ORDERING 3 1 SECTION 3 REPLACEABLE ASSEMBLIES 3 1 INTRODUCTION This section contains information for ordering replacement assemblies The following infor mation is included an explanation of the assembly lists basic ordering information and the procedure for mail ordering parts 3 2 REPLACEABLE ASSEMBLY LIST Table 3 1 provides a listing of the replaceable assemblies and an exp
71. ut ANALOG TEST 1 kHz FAILED This message is displayed when the boards used for the 1kHz measurement have failed ANALOG TEST 1MHz FAILED This message is displayed when the boards used for the 1MHz measurement have failed 2 Self Tests Selected by Softkeys The following self tests can be performed using softkey operations The self tests are performed as follows 1 Press the MENU and PREV keys and the SVC FNCTN softkey 2 Press the SELF TEST softkey to display the Test Menu Page listed in Table 4 3 there are two pages in the the Test Menu Page Press the other menu softkey to swap Test Menu Pages 3 Press the TEST NO softkey 4 Enter the desired test number and press the ENTER key 5 Press the TEST START softkey to start the selected test 6 Press the TEST ABORT softkey to stop the test in progress 4 17 7 Press the TEST MENU softkey to select another test 8 When the seif tests are completed press the exit TEST softkey Table 4 3 Test Menu Page meee NO SELF TEST MENU 1 2 NO SELF TEST MENU 2 2 1 A3 1MHz TRD C offset div test 10 ROM check sum display 2 A3 1MHz TRD Range div test 11 Memory card R W test 3 A3 1MHz TRD 1st null amp test 12 LED display test 4 A3 1MHz TRD 2nd null amp test 13 LCD display test 5 A4 1kHz TRD test 14 Handler I F test 6 A5 1kHz SWM PHD test 7 5 1MHz SWM PHD test 8 A6 ADC test NOTE
72. y Remove the four screws that secure the A90 assembly to the A9 assembly and slide the A90 assembly Disconnect the 2 pin cable from the A9 assembly Disconnect the wires that connect the A90 assembly and the A9 assembly Figure 4 4 A9 A90 and A10 Assembly Removal 4 7 7 A10 ASSEMBLY REMOVAL First remove the front panel assembly from the 4278A as described in paragraph 4 7 4 1 Disconnect the flatcable assembly that is connected to the motherboard from the A10 assembly as shown in Figure 4 4 2 Remove the two screws nuts and washers that secure the A10 assembly to the MEMORY card bezel 4 7 8 A13 ASSEMBLY REMOVAL First remove the front panel assembly from the 4278A as described in paragraph 4 7 4 1 Remove four screws that secure the shield case on which the WARNING is printed as shown in Figure 4 5 2 Remove the screw that secures the A13 assembly to the back of the shield case 3 Disconnect the 3 pin cables from the A 90 assembly 4 Disconnect the 3 pin cables from the A 91 assembly dit dk nea i iae by Figure 4 5 A13 and A91 Assembly Removal 4 7 9 A91 ASSEMBLY REMOVAL First remove the front panel assembly from the 4278A as described in paragraph 4 7 4 1 Remove the four screws that secure the shield case on which the WARNING is printed as shown in Figure 4 5 2 Remove the 3 pin cables connected to the A13 assembly from the A90 and A91 assemblies
73. y the selected softkeys Does the 4278A pass the all of performance tests The 4278A is ON but the LCD display back light is not ON For this problem refer to Figure 4 18 Follow the flow chart shown in Figure 4 14 Follow the flow chart shown in Figure 4 15 Refer to the paragraph 4 9 1 2 and see the description written in the failed number Go to the Table 4 6 and follow the procedure written in the failed test 4 32 START Does the cooing fan on the YES rear pane turn YES Is A1DS1 and 1052 off Turn off Are the fuses blown yes on the A1 board Their loca tion is given in Table 3 5 1 2 NO Replace the A1 board Replace the blown fuse Replace the blown fuse Check the voltages at the test pins on the At board Are voltages within the limits in the following Test Point Limits A1TP12 AiTP13 15 8V to 17 2V 1 14 15 8 to 17 2V AITPIS 12 0V to 13 0V ATTP16 5 0V to 5 4V A1TP17 8 3V to 49 1V A1TP18 Voltage GND 12 0V to 413 0V Turn off Are the fuses blown on the Ai board Their loc tion are given in Table 3 5 1 2 NO Replace the A1 board Turn on the 4278A If the trouble isn t cured yet check other boards for ex cessive power loading Turn off and check continuity of the power line fuse on the rear panel Is the fuse blown
74. you change bit is EEPROM CSUM ERROR NO 0 displayed Catibrate the EEPROM as described in 1 12 and turn on again If same message is switch 783 NO Go to the Digital Circuit Troubleshooting Procedure shawn in the Figure 4 17 4278A Fails The Power On Sel Test displayed turn off and replace the A7 board START Check the that frequency at test pin A2TP9 on A2 board Does 4MHz clock TTL level present at A2TP9 4M Turn off and replace the A2 board YES Check the test signal at YES A2TPS both 1kHz and 1MiMz Is the test signal amplitude coaxial cables labeled G this cable no trouble 1Vrms approximately NO 2 8Vpp 10 both of them Turn off and replace the A2 board Replace this cable 2 5 A2TP9 A2 Board o test Perform the 1 then repeat this test Perform self test number 3 Does the 42784 pass this adjustment described in paragraph 1 11 Does the 4278A pass this tesi NO Turn off and check the coaxial cables labeled B and 1 Are the cabies no trouble Replace the irouble cable Turn off and check the Replace the A3 board is YES Turn on and perform self test number 8 selected by soft keys Does the 4278A pass this test NO Turn off and replace the A6 board Perform self test number 1 Does the 4278A pass this test NO off a

HP Washer/Dryer 4278A User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents