Negative Offset Circuit, DAC Output Switching | Fluke 5720A manual

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Fluke 5720A service manual Negative Offset Circuit, DAC Output Switching, DAC Buffered Reference Sip

Contents

5700A/5720A Series Service ManualMulti-Function Calibrator LIMITED WARRANTY & LIMITATION OF LIABILITY 5/94 Declaration of the Manufacturer or Importer Interference InformationBescheinigung des Herstellers/Importeurs Page LETHAL VOLTAGE OPERATOR SAFETY SUMMARYHIGH VOLTAGE Terms in this Manual Use the Proper Power Cord Symbols Marked on EquipmentPower Source Use the Proper Fuse Do Not Service Alone SERVICING SAFETY SUMMARYFOR QUALIFIED SERVICE PERSONNEL ONLY Use Care When Servicing With Power On Get Help FIRST AID FOR ELECTRIC SHOCKFree the Victim From the Live Conductor Never Accept Ordinary and General Tests for Death Title Table of ContentsIntroduction and Specifications Page 5700A/5720A Series Theory of Operation ±PA Supplies Digital Control How the DAC is Used in Calibration Ohms Cal Assembly A9 Calibration and VerificationCalibration Procedure Rear Panel Assembly Access MaintenanceTroubleshooting Using Remote Commands Reserved for Servicing Schematic Diagrams List of Replaceable Parts viii List of Tables Unregulated Supplies from the Filter Assembly A11A2 DAC Buffered Reference SIP PCA A16A1 Power Amplifier Digital Control SIP PCATest Record for Flatness Check of the AC 2 mV Range A13A1 Oscillator Wideband SMD PCA Service Manual List of Figures Ohms Main Assembly Simplified Schematic Power Amplifier with Calibrator Set to 22V at 1 kHz A15 High Voltage/High Current PCA Service Manual Introduction and Specifications Chapter Service Manual 5700A/5720A Series II Calibrator 1-1. Introduction 1-2. Contacting Fluke 1-4. How to Use this Manual1-3. About this Manual ∙ 5700A/5720A Series II Getting Started Manual PN 1-5. Additional Instruction Manuals1-6. Wideband AC Voltage Module Option 5700A-03 ∙ 5700A/5720A Series II Operator Reference Guide PN 1-7. Auxiliary Amplifiers 1-9. Support Equipment and Services1-8. 5725A Amplifier 1-12. 742A Series Resistance Standards 1-11. 732B-200 Direct Volt Maintenance Program U.S.A. Only1-10. 732B Direct Voltage Reference Standard 1-13. Wideband AC Module Option 5700A-03 Calibration Support 1-14. Service Centers 1-15. The Components of the 5700A/5720A Series II Calibrator 1-16. Calibrating the 5700A/5720A Series II Calibrator Calibrating the 5700A/5720A Series II Calibrator 1-17. The Calibration Process 1-18. Establishing Traceability 1-21. Developing a Performance History 1-20. Calibration Check1-19. Calibration Reports 1-26. Using Absolute and Relative Uncertainty Specifications 1-24. Specifications1-25. Specification Confidence Levels 1-22. Range Calibration 1-27. Using Secondary Performance Specifications Specifications 99 % Confidence Level 1-28. DC Voltage Specifications5720A 95% Confidence Level 99 % Confidence Level DC Voltage Specifications5700A 95 % Confidence Level Overshoot 5 % Common mode rejection 140 dB, DC to 400 Hz 1-29. AC Voltage Specifications AC Voltage Specifications See Volt-Hertz capability in Figure ± 5 C from calibration temperature 99 % Conf idence Level90 Days 95% Confidence Level 0-10 C and ± ppm output + μV±ppm output + mV Figure 1-2. Volt-Hertz Capability 5725A AmplifierdBm reference 600 Ω Resistance Specifications 1-30. Resistance Specifications99% Confidence Level 5700A compensation ±1 C NoteCharacterized active Table 1-13. Current Derating Factors I IL 5720A 99% 1-31. DC Current SpecificationsDC Current Specifications 5720A 95% 5700A Overshoot 5 % 1-32. AC Current Specifications AC Current Specifications 5700A 95 % Confidence Level V rms Temperature Coefficient Note± ppm output + nA maximum load for full accuracy Table 1-22. Wideband AC Voltage Option 5700-03 Specifications 1-33. Wideband AC Voltage Option 5700-03 SpecificationsWideband AC Voltage Option 5700-03 Specifications 1-35 Guard isolation 20 1-34. General SpecificationsSize 5220A AC Current, 180-day specifications 1-35. Auxiliary Amplifier SpecificationsAuxiliary Amplifier Specifications 5205A 220V - 1100 V ac, 0 V - 1100 V dc Overshoot 10 % Service Manual Theory of Operation 2-36 Theory of Operation 2-155 2-3. Internal References 2-1. Introduction2-2. Calibrator Overview 2-4. Hybrid Reference Amplifiers 2-8. Analog Section Overview 2-7. Digital Section Overview2-6. Digital-to-Analog Converter DAC Analog Section Overview Figure 2-1. Digital Section Block Diagramahp003f.eps 2-9. Functional Description Presented by Output Function 2-10. DC Voltage Functional Description Figure 2-2. Analog Section Block Diagram, Part ahp33f.eps Figure 2-3. Analog Section Block Diagram, Part 5700/5720A Series II Calibrator 2-11. AC Voltage Functional Description 2-13. DC Current Functional Description 2-12. Wideband AC V Functional Description Option2-14. AC Current Functional Description 2-16. System Interconnect Detailed Circuit Description 2-17. Digital Motherboard Assembly A42-15. Ohms Functional Description 2-18. Transformer Assembly A22 2-19. Analog Motherboard Assembly A3 Figure 2-4. System Interconnections Functional Description Presented by 0utput Functionahp35f.eps Figure 2-4. System Interconnections cont Motherboard Connector Table 2-1. Analog Motherboard ConnectorsConnected to Assembly 2-24. Digital Power Supply Assembly A19 2-21. Rear Panel Assembly A212-22. Filter PA Supply Assembly A18 2-23. Digital Section Detailed Circuit Description 2-27. +35V Power Supply 2-25. +5V Power Supply2-26. ±12V Power Supplies Digital Section Detailed Circuit Description 2-28. +75V Power Supply 2-29. +35V and +75V Shut-Down Circuit 2-31. Power-Up and Reset Circuit 2-30. CPU Central Processing Unit Assembly A202-32. Clock Generation Figure 2-5. CPU Assembly Block Diagram ahp004f.eps Table 2-3. CPU Acronym Glossary Function Table 2-4. CPU Memory Map 2-33. Watchdog Timer2-34. Address Decoding and DTACK Data Acknowledge Chip Select 2-36. Glue Logic 2-37. RAM Random-Access Memory2-35. Interrupt Controller 2-38. ROM Read-Only Memory 2-40. DUART Dual Universal Asynchronous Receiver/transmitter Circuit 2-39. Electrically-Erasable Programmable Read-Only Memory EEPROM2-41. Clock/Calendar Circuit 2-44. CPU to Front Panel Interface 2-42. Clock Filter Circuit2-43. CPU to Rear Panel Interface 2-45. Fan Monitor 2-48. Refresh Failure Detect Circuitry 2-46. Front Panel Assembly A22-47. Clock Regeneration Circuitry 2-49. Decoding and Timing Circuitry 2-50. Control Display Circuitry êêêêêêê 2-51. Output Display Circuitry 2-52. Keyboard Scanner Circuitry 2-53. Knob Encoder Circuitry 2-55. Keyboard Assembly A1 2-54. Led Circuitry 2-56. Analog Section Detailed Circuit Description 2-57. Filter/PA Supply A18, Low-voltage Filter/Regulator Section 2-60. Unregulated S Supplies 2-58. Unregulated OSC Supplies2-59. Unregulated LH Supplies 2-61. Triac Circuit 2-64. FR2 Supplies 2-65. Filter/PA Supply A18, Power Amplifier Output Supply Section2-66. ±PA Supplies Digital Control Figure 2-6. Power Amplifier Output Supply Simplified Schematic ahp005f.eps 2-69. ±PA Supply Current Limit 2-67. ±250V and ±500V Supplies2-68. +PA and -PA Supplies ∙ PA CT is the center tap 2-71. Voltage Regulator Circuitry 2-70. Regulator/Guard Crossing Assembly A172-72. Regulated OSC Supplies +15 OSC -15 OSC +5RLH +5LH -5LH +44S -44S +17S -17S 15S +30FR1 +30FR2 2-73. Regulated LH Supplies2-74. Regulated S Supplies +15V +5.975V +5.1V +44.15V +17.000V -17.000V +30.96V +30.96V 2-75. FR1 Supply 2-76. FR2 Supply 2-77. Guarded Digital Control Circuitry 2-79. Inguard Memory Configuration2-78. Inguard CPU Memory Map 2-80. Inguard Clock Circuit 2-81. Inguard Watchdog Timer2-82. Power-Up and Reset Circuitry 2-83. Break Detection 2-85. Interface to Guarded Digital Bus 2-87. Switch Matrix Assembly A82-86. Inguard CPU Interrupts 2-88. Switch Matrix Digital Control Figure 2-7. Switch Matrix Assembly Simplified Schematic System Interconnection Detailed Circuit Description 2-89. Switch Matrix Operation 11V DC and 22V DC Ranges 3. Apply 7V to the relay coils by setting PC5 high Figure 2-8. Switch Matrix Configuration for 11V DC and 22V DC Ranges ahp006f.eps 2-90. Switch Matrix Operation 2.2V AC and 22V AC Ranges 2-91. Switch Matrix Operation 220V AC and DC Ranges Figure 2-9. Switch Matrix Configuration for 2.2V and 22V AC Ranges ahp007f.eps Figure 2-10. Switch Matrix Configuration for 220V DC and AC Ranges ahp008f.eps 2-92. Switch Matrix Operation 2.2V DC Range Figure 2-11. Switch Matrix Configuration for 2.2V DC Range ahp009f.eps 2-93. Calibration of the 2.2V Range 2-94. Switch Matrix Operation 220 mV DC RangeTo calibrate the offset Figure 2-12. Calibration of the 2.2V DC Range ahp010f.eps Figure 2-13. Switch Matrix Configuration for 220 mV DC Range ahp011f.eps 2-96. Switch Matrix Operation 2.2 mV and 22 mV AC Ranges 2-95. Switch Matrix Operation 220 mV AC Range2-97. Calibration of the mV Ranges Figure 2-14. V AC, 2.2 mV AC, and 22 mV AC Range ahp012f.eps Figure 2-15. Divider Calibration ahp013f.eps 2-98. Internal CAL Zero Amplifier Figure 2-16. Divider Gain Calibration ahp014f.eps 2-100. DAC Assembly A11 2-99. Switch Matrix 5725A Amplifier Interface2-101. Basic DAC Theory of Operation 0.1 x 13V + 0.5 x 0.78 mV = Figure 2-17. DAC Assembly Simplified Schematic ahp015f.eps 2-103. DAC Assembly Reference Circuitry 2-102. DAC Assembly Digital ControlProgrammable Peripheral Interface IC U31 is the heart of this circuit 2-104. Duty-Cycle Control Circuit 2-106. DAC Output Stage 2-105. DAC Filter CircuitREFCOM 2-107. Sense Current Cancellation Circuit 2-108. Linearity Control Circuit 2-109. Negative Offset Circuit 2-110. DAC Output Switching2-111. DAC Buffered Reference Sip 2-113. ADC Amplifier 2-112. Calibration Hardware2-114. ADC Input Selection 2-115. ADC Circuit ∙ ADC reference voltage ∙ ADC dac ∙ ADC comparator/amplifier Figure 2-18. ADC Circuit Measurement Functions ahp016f.eps 2-116. How the DAC is Used in Calibration 2-117. DAC Assembly CalibrationINPUT 2-119. Oscillator Control Assembly A12 2-118. Oscillator Section Overview 2-122. Sense Current Cancellation 2-121. Oscillator Input Switching2-120. Oscillator Control Digital Control 2-125. Three-Pole Filter 2-124. Error Integrator2-123. Averaging Converter 2-126. Analog Amplitude Control Loop Figure 2-19. Oscillator Control Analog Control Loop ahp017f.eps 2-127. AC/DC Thermal Transfer Circuit Figure 2-20. AC/DC Thermal Transfer Circuit ahp018f.eps 2-128. Oscillator Calibration 2-130. Oscillator Output Assembly A13 2-129. AC/DC Frequency Response Characterization Figure 2-21. Quadrature RC Oscillator Circuit ahp019f.eps 2-131. Oscillator Output Digital Control 2-132. Quadrature RC Oscillator 2-134. Phase−locked Loop 2-133. Oscillator Amplitude Control 2-136. Oscillator Wideband Smd Assembly A13A1 2-135. 2.2V and 22V Range Output Amplifier 2-139. Power Amplifier Assembly A16 2-138. Phase Shifter2-137. Output Stage 2-140. Power Amplifier Digital Control Sip Assembly A16A1 1. Write the proper data for these relays to port A of the 82C55 U11 2-143. PA Input Stage 2-141. PA Common Circuitry2-142. +PA and -PA Supplies ∙ ±185V ∙ ±365V 2-144. PA Mid Stage 2-145. PA Output Stage 2-147. PA in Standby 2-146. PA Sense Current Cancellation Circuitry2-148. PA Operation 220V DC Range Figure 2-22. Power Amplifier Simplified Schematic ahp020f.eps 2-151. High Voltage AC 1100V Range 2-150. High Voltage Assembly Support Mode2-149. PA Operation 220V AC Range 2-152. High Voltage DC 1100V Range and Current 2.2A Range 2-153. 220V DC Internal Calibration Network 2-154. PA Calibration Figure 2-23. Power Amplifier DC Calibration Network ahp021f.eps Power Amplifier dc gain of approximately -20 is calibrated next. The Power Amplifier is configured as in the 220V dc operation, except the input is connected to the DAC’s 6.5V reference BRF6 and BSRF6 by U2C and U2D respectively. The resulting -130V at the Power Amplifier output is connected to the 175 kΩ end of the internal cal resistor network by relay K3. The 25 kΩ end of this network is connected to DAC OUT HI and DAC SENSE HI by relay K1. The output of the internal cal amplifier is connected to the DAC’s adc circuit as in the previous steps, and the DAC OUTPUT is adjusted until checkpoint is measured by the adc circuit. Since the exact attenuation of the resistor networks is already known, the exact Power Amplifier output voltage can be calculated. This in turn gives the exact Power Amplifier dc gain, since the exact value of 6.5V reference BSRF6 is known Figure 2-24. Power Amplifier Calibration AC Attenuator f2-24.eps 2-155. High Voltage Assemblies A14 and A15 2-156. 1100V AC Range Figure 2-25. High Voltage/High Current Assembly 1100V AC Range ahp022f.eps 2-157. 1100V DC Range 2-158. HVDC Power Supply Filter Circuit2-159. HV DC Output Series Pass and Current Limit Circuit Figure 2-26. High Voltage/High Current Assembly 1100V DC Range ahp023f.eps 2-160. DC HV Amplifier/AC Sense Buffer 2-161. 2.2A Range Figure 2-27. High Voltage/High Current Assembly 2.2A AC and DC Ranges ahp024f.eps 2-162. 2.2A Power Supply Filter Circuit 2-163. High Voltage Digital Control 2-164. High Voltage Calibration 2-165. Calibration of the AC Function Figure 2-28. High Voltage/High Current Assembly Calibration ahp025f.eps 2-166. Calibration of the Current Function 2-167. High Voltage Magnitude Control ahp026f.eps 2-168. Ohms Overview 2-169. Ohms Main Assembly A10 2-170. Selection of Resistance Values Figure 2-30. Ohms Assemblies Simplified Schematic ahp38f.eps Analog Selection Detailed Circuit Description Figure 2-31. Ohms Main Assembly Simplified Schematicahp39f.eps 2-172. Ohms Digital Control 2-171. Ohms Main Assembly Support of Current Function Calibration2-173. Ohms Cal Assembly A9 2-174. Ohms CAL Digital Control 2-176. Two-Wire Ohmmeter Compensation Circuit 2-175. 1, 1.9, and Short Resistance Figure 2-32. Two-Wire Lead Drop Compensation Circuit ahp027f.eps 2-179. Low Side Cancellation 2-177. Two-Wire Compensation Power Supplies2-178. High Side Cancellation 2-180. Ohms Calibration Figure 2-33. Calibration to an External 10 kΩ Standard ahp028f.eps 2-181. Calibrating to the External 10 KW Standard 2-183. Calibrating 100 KW 2-182. Calibrating 10 KW and 19 KW2-184. Completion of High Resistance Value Calibration The 10Ω, 19Ω, 100Ω and 190Ω resistance values are determined using 2V from the 2/5/10V source and using internal 101 divider Z5 in conjunction with the DAC. To get 2V, Q2 and Q3 are both turned on, which parallels both the 11.535 kΩ value and the 3.846 kΩ value with the 50 kΩ value. The lower voltage is required to lower the power dissipation in the resistors Figure 2-34. Ratio Calibration, 10 Ω From 100 Ω ahp029f.eps 2-186. Current/High Resolution Oscillator Assembly Overview A7 2-185. Calibrating to the External 1W Standard 2-188. Current Input Switching 2-187. Current Section Figure 2-35. Current Output Simplified Schematic ahp030f.eps 2-190. Transconductance Amplifiers 2-189. Complementary Drive Circuit2-191. Shunt Resistors 2-194. Generation of the 2.2A Range 2-193. Current Output Switching2-192. Feedback Loop Table 2-15. Relay Settings for Current Range Selection Range 2-196. Compliance Limiter 2-198. Current Assembly Calibration2-195. Current Guard Buffer 2-197. Current/Compliance Voltage Monitor Figure 2-36. Current Assembly Calibration ahp031f.eps 2-199. High-Resolution Oscillator Section ∙ 10.00 Hz to 119.99 Hz ∙ 0.1200 kHz to 1.1999 kHz 2-201. Phase-Locked Loop 2-200. Reference Frequency Amp/Divider 2-204. Rear Panel Assembly A21 2-203. Hi-Res Output Switching2-202. 5-500k Output Divider 2-206. Rear Panel Address Mapping 2-205. Rear Panel Power Supplies∙ RPDUARTCS*, D00000-D0001F ∙ RPIEEECS*, D00020-D0002F 2-208. IEEE-488 GPIB Interface 2-207. Clock Regeneration Circuit2-209. RS-232C Interface 2-210. Auxiliary Amplifier Interface 2-212. Phase Lock In/Variable Phase out2-211. 5725A Interface 2-214. Rear Panel CPU Interface 2-213. Rear Panel Relay ControlPort A PA0-PA7 provides the input lines for relay driver U16 2-215. Wideband AC Module Option 2-216. Wideband Oscillator Assembly A62-217. Wideband Oscillator Power Supplies 2-218. Wideband Oscillator Digital Control 2-219. Phase-Locked Loop and Divider Circuit 2-220. Amplitude Control Amplifier and X10 Wideband Amplifier 2-221. Wideband Oscillator Filters 2-222. Wideband Output Assembly A5 Figure 2-37 is a simplified schematic for the Wideband Output assembly Figure 2-37. Wideband Output Assembly Simplified Schematic ahp032f.eps 2-223. Wideband Output Power Amplifier Circuit 2-225. Wideband Output RMS Sensor and Amplitude Control Circuit 2-224. Wideband Output Attenuators2-226. Wideband Output Overload Control Circuit 2-227. Wideband Output Digital Control 2-228. Wideband Output Calibration connector is connected back to the OUTPUT HI SENSE and OUTPUT LO SENSE binding posts Service Manual Calibration and Verification 3-30 3-1. Introduction Calibration and Verification 3-2. Accessing the Fuse 3-3. Cleaning the Air Filter Cleaning the Air Filter 3-5. Calibration 3-4. Cleaning the Exterior3-6. Calibrating the 5700A/5720A Series II to External Standards 3-7. Calibration Requirements 3-8. When to Adjust the Calibrator’s Uncertainty SpecificationsCalibrating the 5700A/5720A Series II to External Standards 3-9. Calibration Procedure Figure 3-3. 732B External Calibration Connections 4. Enter the ambient temperature then press E. The display shows5. Connect the 732B to the calibrator as shown in Figure 732B DC STANDARD IF3-6.EPS IF3-5.EPSIF3-7.EPS After a few seconds, the following display appears Figure 3-4. 742A-1 and 742A-10k External Calibration Connections RESISTANCE STANDARDCALIBRATOR F7-4.EPS 16. Set the rear panel CALIBRATION switch to NORMAL 3-10. Range Calibration 4. Press the “DC V” softkey to bring up the next menu shown below PREV MENU IF057.EPS 3-11. Calibrating the Wideband AC Module Option 5700A-03 Calibrating the Wideband AC Module Option 5700A-03 2. Press the “Cal “ softkey to bring up the following menu 4. Press the “Gain” softkey to bring up the following display 3-12. Performing a Calibration Check Press Pto exit the calibration menus 3-13. Full Verification Figure 3-7. Overview of Verification Tests 3-15. Warm-up Procedure for All Verification Tests 3-14. Required Equipment for All Tests Application Table 3-2. List of Required Equipment for Main OutputEquipment Equipment Required for Wideband Ac Module Option 5700-03 Verification 3-16. Resistance Verification Test 13. The low-value 1Ω, 1.9Ω, and 10Ω tests are summarized in Table 3-17. Two-Wire Compensation Verification 3-18. DC Voltage Verification Test 3-19. DC Voltage One-Tenth Scale Linearity Test 3-20. Direct Current Accuracy Verification Test 3-21. AC Voltage Frequency Accuracy Test 3-22. Output Level Tests For AC V Ranges Use Table 3-23 5720A or Table 3-24 5700A for the test records 5790A Adjustment Counts 3-23. AC Current Test, 22 mA to 11A RangesTable 3-8. 5790A Adjustment Counts 5700A/5720A Series II Output Level 1. Connect the equipment as shown in Figure 3-12A use the 2A shunt B. Alternating Current Test Setup, 10A Using 5790A Input Figure 3-12. Alternating Current Test SetupA. Alternating Current Test Setup, 22 mA to 2A Using 5790A Input 5790A Metal Film Resistor Mounted on Dual Banana Plug 200 3-24. AC Current Test, 2 mA and 200 μA RangesHi Output Lo Pomona Cable 1362-A-18 Figure 3-14. Metal Film Resistor Equivalent Circuit 3-25. Rationale for Using Metal-Film Resistors to Measure AC CurrentFigure 3-15. Metal Film Resistor in Test Circuit 3-26. Wideband Frequency Accuracy Test 3-27. Wideband AC Voltage Module Output Verification 3-28. Wideband Output Accuracy at 1 kHz Test Wideband Output Accuracy at 1 kHz Test 3-29. Wideband Output Flatness Test 3-30. Wideband Flatness Calibration Procedure 3-31. Optional Tests 3-32. DC Voltage Load Regulation Test 3-34. DC Voltage Output Noise 10 Hz to 10 kHz Test 3-33. DC Voltage Linearity TestOptional Tests 2. Set the Oscilloscope Differential Amplifier controls as shown below 3-36. AC Voltage Distortion Test 3-37. Wideband Distortion Testing3-35. DC Voltage Output Noise 0.1 to 10 Hz Test WWarning 3-39. Minimum Use Requirements 3-38. AC Voltage Overshoot Test Table 3-15. Minimum Use Requirements Minimum Use SpecificationsMinimum Use Requirements Calibration Equipment 3-40. Determining Test Limits for Other Calibration Intervals 130 + 1000000*0.000000040/0.002=130 ppm + 20 ppm = 150 ppm 1Ω Std Voltage DMM Error1Ω Std Res Value Measured 1Ω Std Voltage DMM UUT Res Value Table 3-16. 5720A Resistance Test Record contUUT True Res Value UUT 1Ω Voltage Table 3-17. 5700A Resistance Test RecordUUT 1Ω Displayed Value UUT True Res Table 3-17. 5700A Resistance Test Record cont Max Difference of Characterized to Nominal Value 5720A Range Divider SettingTable 3-18. DC Voltage Test Record for 5720A 5720A Output 5700A Range Table 3-19. DC Voltage Test Record for 5700A5700A Output Error A+B UUT ErrorSetting Table 3-20. Direct Current Accuracy Test Record 5720A Test Limit 90-day ppm Table 3-21. Direct Current Accuracy Test Record 5700A5725A Amplifier DC Current Test DC DMM Reading Output Error Display ReadingTable 3-23. 5720A AC Voltage Output Test Record Level Table 3-23. 5720A AC Voltage Test Record cont ErrorOutput Level Display Table 3-24. 5700A AC Voltage Output Test Record Characterized 1.9 mV Reading Table 3-24. 5700A AC Voltage Output Test Record contTable 3-25. AC Voltage 2 mV Range Test Record Limits Table 3-26. 5720A AC Current 20 mA to 10A Accuracy Test Record UUT Error DisplayCalculated Error 2A, 200 mA, 20 mA and 10A Test Record 2A, 200 mA, 20 mA and 10A Test Record 10A Only for 5725A Table 3-27. 5700A AC Current 20 mA to 10A Accuracy Test RecordSpecs ±ppm 5790A Transfer Spec ± ppm Table 3-28. 5720A AC Current 2 mA and 200 μA Accuracy Test RecordSpec ± ppm 90-day Test Limits ± ppm Frequency Measured Table 3-30. Wideband Frequency Accuracy Test RecordFrequency Hz Tolerance Limits Table 3-31. Wideband Accuracy at 1 kHz Test Record Measured ErrorMeasured Flatness Error 5790A 1-Year Spec ± ppm Table 3-32. Wideband Flatness Test Record cont Flatness Error ppm Table 3-33. Wideband Absolute Error 10 Hz to 500 kHz1 kHz Absolute Error ppm Error Sum ppm Table 3-34. Load Regulation Test Record Div. SettingKelvin-Varley Setting 5700A/5720A Series Range 5700A/5720A Series II Output UUT Error Display ReadingTable 3-37. AC V Distortion Test Summary Load Resistors static awareness A Message FromFluke Corporation 5. USE STATIC SHIELDING CONTAINERS FOR HANDLING AND TRANSPORT Maintenance Title Service Manual 4-2. Cleaning the Air Filter 4-1. Introduction 4-5. Access Procedures 4-3. General Cleaning4-4. Cleaning PCA’s 4-9. Rear Panel Removal and Installation 4-10. Rear Panel Assembly Access 4-11. Front Panel Removal and Installation 4-12. Display Assembly Removal and Installation 4-13. Keyboard Assembly Removal and Installation 4-14. Analog Assembly Removal and Installation Figure 4-5. Analog and Digital Assemblies FRONT PANEL 4-16. Power Transformer Removal and Installation 4-18. Front/Rear Binding Post Reconfiguration4-15. Digital Assembly Removal and Installation 4-17. Hybrid Cover Removal 6. Install the Front Panel 4-21. Replacing the Clock/Calendar Backup Battery 4-19. Installing a Wideband AC Module Option4-20. Clearing Ghost Images from the Control Display Using The Fatality? and Fatalclr Commands 4-22. Using Remote Commands Reserved for Servicing4-23. Using the ETIME Command ETIME FATLCLR? FATALITY?Response Service Manual Troubleshooting Service Manual 2702 A7 8255 Port B Fault 5-2. Interpreting Diagnostic Fault Codes2701 A7 8255 Port a Fault 2703 A7 8255 Port C Fault 2707 A7 Hardware Initialization Fault 2705 A7 Oven Regulation Fault2706 A7 Current Compliance Fault 2709 A7 Current Magnitude Fault 2713 A7 Hi-Res Loop In 100Hz Range 2718 Fault In Setting Up AC For Diagnostics2719 A7 8255 Was Reset 2714 A7 Hi-res Loop In 1kHz Range 2803 A11 8254 Status Words 2801 A11 8255 Port a Wires2802 A11 8255 Port B Data Bus 2804 A11 DAC Heaters Not Regulated 2810 A11 +11V DC Range Fault 2808 A11 ADC Amp Gain Error2809 A11 DAC Monitoring Fault 2811 A11 -11V DC Range Fault 2817 A11 13V Reference Fault 2815 A11 6.5V Reference Fault2816 A11 13V Buffered Reference Fault 2818 Assembly A11 Missing 3101 A14 8255 Port a Fault 2822 A8/A11 -11/22V DC Zero Estimate Fault2826 A11 A/D Overload Fault 3102 A14 8255 Port B Fault 3105 A15 HV I Oven Regulation Fault 3103 A14 8255 Port C Fault3104 A15 HV Oven Regulation Fault 3106 A15 DC HV Amp Noise Fault 3111 A15 HV +DC High Voltage Output Fault 3109 A15 HV +DC Preamplifier Fault3110 A15 HV +DC Series Pass & Current Fault 3112 A15 HV +DC Ref/error Amplitude Fault 3118 A14/A15 HV -DC Current Error Amp Fault 3116 A15 HV -DC Reference/error Amp Fault3117 A14/A15 HV +DC Current Error Amp Fault 3119 A14/A15 HV +DC Current Abs. Value 3123 A14/A15 HV AC 1kHz, Preamp Mid 3126 A14/A15 HV AC 100Hz, Preamp Fault3122 A14/A15 HV AC 1kHz, Preamp Lo 3124 A14/A15 HV AC 1kHz, Preamp Hi 3130 A14/A15 HV AC 1kHz, Output Hi 3128 A14/A15 HV AC 1kHz, Output Lo3129 A14/A15 HV AC 1kHz, Output Mid 3131 A14/A15 HV AC 100Hz, Output Lo 3137 A14/A15/A16 2.2A AC Range Mag. Fault 3135 Assembly A14 Not Responding3136 A14 8255 Was Reset 3134 Spare 3140 A14/A15/A16 2.2A AC Range Abs. Value 3301 A9 8255 Port a Fault3302 A9 8255 Port B Fault 3141 A14/A15/A16 2.2A DC Range Dummy Load 3305 A9 5V Source Fault 3303 A9 8255 Port C Fault3304 A9 10V Source Fault 3306 A9 2V Source Fault 3311 A9/A10 Ohms 101 Divider Fault 3309 A9 Diff Amp Gain Fault3310 A9 Diff Amp Noise Fault 3312 A9/A10 Ohms 11 Divider Fault 3317 A9/A10 100 Kilohm Ratio Fault 3315 A9/A10 10 Ohm Cal Diag Fault3316 A9/A10 19 Ohm Cal Diag Fault 3318 A9/A10 190 Kilohm Ratio Fault 3325 A9/A10 10 Kilohm Check Fault 3321 A9/A10 10M Ohm Ratio Fault3324 A9/A10 100M Ohm Ratio Fault 3326 A9/A10 19 Kilohm Check Fault 3329 A9/A10 100 Ohm Check Fault 3327 A9/A10 1 Kilohm Check Fault3328 A9/A10 1.9 Kilohm Check Fault 3330 A9/A10 190 Ohm Check Fault 3336 A9/A10 2 Wire Compensation Fault 3334 A9/A10 1.9 Ohm Check Fault3335 A9/A10 Ohms Short Check Fault 3337 A9/A10 Ohms Correction Factor Fault 3401 A12 8255 Port A 3341 A9/A10 190 Ohm Cal Diag Fault3400 A12 8255 Control Word 3402 A12 8255 Port B 3410 A12/A13 22V Amp Bias Adj Error 3408 A13 Fixed Ampl. Osc Fault3409 A13 Phase Lock Loop Fault 3412 A12 To A13 Interface Fault 3418 A12 Sensor Loop/SQ. Root Amp Fault 3416 A12/A13 DAC 15th Bit Fault3417 A12 DC Sensor Buffer Fault 3414 A12/A13 Nonlinear Control Loop 2vrng 3425 Assembly A12 Or A13 Not Responding 3423 Assembly A12 Missing3424 Assembly A13 Missing 3426 A12 8255 Was Reset 3503 A16 8255 Port C 3508 A16/A14 220V AC Range Output Fault3510 A16 220V Amp Fault 3504 Spare 3512 Spare 3520 A16 PA Oven Regulation Fault3511 A16 Incorrect PA Input 3513 Spare 3525 220V DC Initialization Fault 3521 Assembly A16 Is Not Responding3524 A16 Power Amp Is Too Hot 3526 220V AC Initialization Fault 3601 -17S Supply Fault 3530 A16 8255 Was Reset3600 +17S Supply Fault 3602 +15S Supply Fault 3607 -5lH Supply Fault 3605 -42S Supply Fault3606 LH Com Ground Fault 3608 +5rLH Supply Fault 3613 -15 OSC Supply Fault 3611 -PA Supply Fault3612 +15 OSC Supply Fault 3614 OSC Com Ground Fault 3702 A21 8255 Port B Fault 3615 S Com Ground Fault3701 A21 8255 Port A Fault 3703 A21 8255 Port C Fault 3803 A8 8255 Port C Fault 3801 A8 8255 Port A Fault3802 A8 8255 Port B Fault 3804 A8 Zero Amp Lo Noise Fault 3812 A8 2.2V Gain Fault 3813 A8 220mV Offset Fault 3809 A8 Zero Amp Hi Gain Fault3810 A8 2.2V Amp Noise Fault 3811 A8 Zero Amp Offset 3814 A8 220mV Divider Fault 3815 A8 22mV Divider Fault 3816 Spare 3826 A8 8255 Was Reset 3824 A8 Oven Regulation Fault3825 Assembly A8 Not Responding 3827 Assembly A8 Too Hot 3900 A5 8255 Control Word 3907 A5 Rms Sensor At 10MHz 3905 A6 Phase Lock Loop At 10MHz3906 A6 Phase Lock Loop At 30MHz 3908 A5 Rms Sensor At 30MHz 3911 A5/A6 Ampl. Control At 30MHz 3914 A5 0DB Output Attenuation Fault3915 A5 10DB Output Attenuation Fault 3912 A5/A6 Output Offset At 10MHz 3918 A5 40DB Output Attenuation Fault 3916 A5 20DB Output Attenuation Fault3917 A5 30DB Output Attenuation Fault 3922 A5/A6 Wideband Initialization Fault 3923 A5 8255 Was Reset 5-3. Component-level Troubleshooting5-4. Troubleshooting the Wideband Output Assembly A5 Component-level Troubleshooting 5-5. Troubleshooting the Wideband Oscillator Assembly A6 All measurements are referenced to SCOM TP16 or TP17 and all Figure 5-2. Waveform at TP1 F5-2.EPS Figure 5-3. Waveform at TP15 F5-3.EPS Figure 5-4. Waveform at Pins 14 and 15 of U1 F5-4.EPS 10 ms F5-5.EPS 5-6. Troubleshooting the Current/Hi-Res Assembly A7 5-7. Current Section Figure 5-6. Waveform at Pin 11 of K2 F5-6.EPS K5C, K5D Figure 5-7. Waveform at Pin 6 of K21.2 Ω K10, K13 F5-9.EPS F5-10.EPS F5-11.EPS 5-8. Hi-Res Oscillator Section All measurements are referenced to LHCOM TP18 Figure 5-13. Waveform at TP12 F5-13.EPS 5-9. Troubleshooting the Switch Matrix Assembly A8 Figure 5-15. Waveform at TP16 F5-15.EPS 5-10. Troubleshooting the Ohms Cal Assembly A9 5-11. Two-wire Compensation Circuit 5-12. Troubleshooting the Ohms Main Assembly A10 5-13. Troubleshooting the DAC Assembly A11 F5-17.EPS Figure 5-17. Waveform at TP6Figure 5-18. Waveform at TP4, Calibrator Set to F5-18.EPS Figure 5-19. Waveform at TP4, Calibrator Set to F5-19.EPS Figure 5-20. Waveform at TP7 F5-20.EPS Figure 5-21. Waveform at TP5 F5-21.EPS 5-14. Duty-cycle Control Circuit Figure 5-22. Waveform at Pin 10 of U6 F5-22.EPS F5-23.EPS Figure 5-23. Waveform at Pin 6 of U13Figure 5-24. Waveform at Pin 4 of U10 F5-24.EPS U11, Q30, Q31, Q32, and their associated components 5-15. ADC Circuit 5-16. Buffered Reference SIP Assembly A11A2 5-17. Troubleshooting the Oscillator Control Assembly A12 F5-27.EPS Figure 5-27. Waveform at Anode of CR4Figure 5-28. Waveform at Pin 6 of U11 F5-28.EPS Figure 5-29. DC Sense Buffer Waveform TP6 F5-29.EPS 5-18. Troubleshooting the Oscillator Output Assembly A13 ∙ TP5 positive voltage ∙ TP4 negative voltage ∙ TP3 positive voltage 5-19. Troubleshooting the High Voltage Control Assembly A14 Figure 5-31. Waveform at TP3 F5-31.EPS 5-20. Magnitude Control Circuit 5-21. Troubleshooting the High Voltage/High Current Assembly A15 operation refer to Figure 2-25 in the Theory of Operation section. During normal operation in the 1100V ac mode, internal software monitors the output and makes corrections or trips the instrument into standby. This internal monitoring can cause difficulty when troubleshooting a faulty High Voltage assembly. If during the next step 8 the instrument keeps tripping into standby, defeat the monitoring by connecting a jumper from TP9 to TP10 on the DAC assembly 5-22. Troubleshooting the Power Amplifier Assembly A16 Figure 5-32. Waveform at Pin 18 of Hybrid H4 Figure 5-33. Power Amplifier with Calibrator Set to 22V at 1 kHz AC elsewhere in the Calibrator Remove any jumpers left in place from step 8 before continuing 5-23. Troubleshooting the Filter/PA Supply Assembly A18 J201. The +PA supply at +180Vshould go into current limit. The oscilloscope should show a repeating pattern in which the +PA supply climbs to about +180V then drops to 0V. If a failure is detected, check Q203, VR246, VR213, U201C, and associated components Service Manual List of Replaceable Parts Service Manual 6-1. Introduction 6-2. How to Obtain PartsA * symbol indicates a device that may be damaged by static discharge 6-3. Manual Status Information Ref or Option No 6-5. Service CentersManual Status Information Assembly Name Fluke Reference Description Designator Service CentersTable 6-1. Front Panel Final Assembly Fluke Stock No 5700A-T&B Figure 6-1. Front Panel Final Assemblyf6-1.eps Table 6-1. Chassis Final Assembly 1 of Figure 6-2. Chassis Final Assembly5700A T&B f61a1.eps Figure 6-2. Chassis Final Assembly cont f61a2.eps Table 6-1. Rear Panel Final Assembly Figure 6-3. Rear Panel Final Assembly f61b.eps CR1-4 DT1, DT2 W1 ISOLATOR,OPTO,OPTICAL SWITCH,INFRAREDTable 6-2. A1 Keyboard PCA LED,GREEN,SUBMINIATURE 5700A-1603 Figure 6-4. A1 Keyboard PCA Table 6-3. A2 Front Panel PCA Designator Table 6-3. A2 Front Panel PCA cont Figure 6-5. A2 Front Panel PCA 5700A-160257001602.EPS Table 6-4. A3 Analog Motherboard PCA 5700A-1601 Figure 6-6. A3 Analog Motherboard PCA Table 6-5. A4 Digital Motherboard PCA Figure 6-7. A4 Digital Motherboard PCA 5700A-160557001605.EPS Table 6-6. A5 Wideband Output PCA, Option Table 6-6. A5 Wideband Output PCA, Option -03 cont R69,R70 R72,R73,R80-83 R74 R75 R78,R79,R86-89 R92-95 R96-99 R100 R101 Figure 6-8. A5 Wideband Output PCA, Option 5700A-161157001611.EPS Table 6-7. A6 Wideband Ocillator PCA, Option CONNECTOR ,CONN,DIN41612,TYPE C,RT ANG,64 PIN Table 6-7. A6 Wideband Ocillator PCA, Option -03 cont R58,R112,R212 R312,R412,R512 R59 R61 R62,R64,R65,R69 R63 R68 R71 Figure 6-9. A6 Wideband Oscillator PCA, Option 5700A-161057001610.EPS Table 6-8. A7 Current/High-Res Oscillator PCA Table 6-8. A7 Current/High-Res Oscillator PCA cont Table 6-8. A7 Current/High-Res Oscillator PCA cont Figure 6-10. A7 Current/HIgh-Res Oscillator PCA 5700A-162157001621.EPS Table 6-9. A8 Switch Matrix PCA Reference Designator Table 6-9. A8 Switch Matrix PCA cont 5700A-1622 Figure 6-11. A8 Switch Matrix PCA57001622.EPS Table 6-10. A9 Ohms Cal PCA Table 6-10. A9 Ohms Cal PCA cont Figure 6-12. A9 Ohms Cal PCA 5700A-163157001631.EPS Table 6-11. A10 Ohms Main PCA Figure 6-13. A10 Ohms Main PCA 5700A-163057001630.EPS Table 6-12. A11 DAC PCA C110,C111 CR1,CR3-6,CR8, CR12,CR13 CR2 Table 6-12. A11 DAC PCA cont List of Replaceable Parts VR13 VR18,VR22 VR25 VR26 VR27 VR28 VR29 VR33,VR34 X1 Z2 Z4 Z5 Z8 Z10 Figure 6-14. A11 DAC PCA 5700A-164057001640.EPS Table 6-13. A11A1 DAC Filter SIP PCA 5700A-1643 Figure 6-15. A11A1 DAC Filter SIP PCA Table 6-14. A11A2 DAC Buffered Reference SIP PCA 5700A-1644 Figure 6-16. A11A2 DAC Buffered Reference SIP PCA Table 6-15. A12 Oscillator Control PCA Table 6-15. A12 Oscillator Control PCA cont Stock Table 6-15. A12 Oscillator Control PCA cont Figure 6-17. A12 Oscillator Control PCA 5700A-165057001650.EPS Table 6-16. A13 Oscillator Output PCA Table 6-16. A13 Oscillator Output PCA cont 5700A/5720A Series II Calibrator Figure 6-18. A13 Oscillator Output PCA 5700A-165157001651.EPS Table 6-17. A13A1 Oscillator Wideband SMD PCA 5700A-1652 Figure 6-19. A13A1 Oscillator Wideband SMD PCA Table 6-18. A14 High Voltage Control PCA Table 6-18. A14 High Voltage Control PCA cont Figure 6-20. A14 High Voltage Control PCA 5700A-166157001661.EPS Table 6-19. A15 High Voltage/High Current PCA Table 6-19. A15 High Voltage/High Current PCA cont Figure 6-21. A15 High Voltage/High Current PCA 5700A-166057001660.EPS Table 6-20. A16 Power Amplifier PCA CR20,CR21,CR23 Table 6-20. A16 Power Amplifier PCA cont R9,R10,R16,R33, R40,R50 R59, R115,R148 R149 R11,R12 Table 6-20. A16 Power Amplifier PCA cont 5700A-7670 Figure 6-22. A16 Power Amplifier PCA57001670.EPS Table 6-21. A16A1 Power Amplifier Digital Control SIP PCA Figure 6-23. A16A1 Power Amplifier Digital Control SIP PCA 5700A-1671 Table 6-22. A17 Regulator/Guard Crossing PCA Table 6-22. A17 Regulator/Guard Crossing PCA cont Figure 6-24. A17 Regulator/Guard Crossing PCA 5700A-168057001680.EPS Table 6-23. A18 Filter/PA Supply PCA CR1,CR2,CR04, CR5 CR8,CR10, CR12,CR13 Table 6-23. A18 Filter/PA Supply PCA cont VR211,VR217 VR227,VR231 VR212,VR216 VR226,VR232 VR214,VR230 Figure 6-25. A18 Filter/PA Supply PCA 5700A-769057001690.EPS Table 6-24. A19 Digital Power Supply PCA C24,C25 CR1-4,CR9-12 CR8,CR16, CR21- 24,CR29-34 Table 6-24. A19 Digital Power Supply PCA cont 5700A-1604 Figure 6-26. A19 Digital Power Supply PCA57001604.EPS Ref Des Table 6-25. A20 CPU PCAPart Number Table 6-26. A20 CPU PCA cont Figure 6-27. A20 CPU PCA 57001606.EPS Table 6-27. A21 Rear Panel PCA Table 6-27. A21 Rear Panel PCA cont Figure 6-28. A21 Rear Panel PCA 5700A-160957001609.EPS Service Manual Schematic Diagrams Service Manual Schematic Diagrams Figure 7-1. A1 Keyboard PCA 5700A/5720A Series Figure 7-1. A1 Keyboard PCA cont Figure 7-2. A2 Front Panel PCA Figure 7-2. A2 Front Panel PCA cont Schematic Diagrams Figure 7-2. A2 Front Panel PCA cont 5700A/5720A Series Service ManualFigure 7-2. A2 Front Panel PCA cont Schematic Diagrams Figure 7-3. A3 Analog Motherboard PCA Figure 7-23. A3 Analog Motherboard PCA cont Figure 7-3. A3 Analog Motherboard PCA cont Schematic Diagrams Figure 7-3. A3 Analog Motherboard PCA cont 5700A/5720A Series Figure 7-4. A4 Digital Motherboard PCA Figure 7-4. A4 Digital Motherboard PCA cont ahp46f.tif 5700A/5720A Series 5700A-1611 Figure 7-5. A5 Wideband Output PCA Option Figure 7-5. A5 Wideband Output PCA Option -03 cont Schematic Diagrams Figure 7-5. A5 Wideband Output PCA Option -03 cont 5700A/5720A Series 5700A-7610 7-23Figure 7-6. A6 Wideband Oscillator PCA Option Figure 7-6. A6 Wideband Output PCA Option Figure 7-6. A6 Wideband Oscillator PCA Option -03 cont 5700A/5720A Series Figure 7-7. A7 Current/High-Resolution Oscillator PCA 5700A-1621 Figure 7-7. A7 Current/High-Resolution Oscillator PCA cont Schematic Diagrams Figure 7-7. A7 Current/High-Resolution Oscillator PCA cont Figure 7-7. A7 Current/High-Resolution Oscillator PCA cont 5700A-1021 4 of Figure 7-7. A7 Current/High-Resolution7-31 Oscillator PCA cont Figure 7-8. A8 Switch Matrix PCA 5700A-1622 Figure 7-8. A8 Swith Matrix PCA cont Figure 7-8. A8 Switch Matrix PCA cont Schematic Diagrams Figure 7-8. A8 Swith Matrix PCA cont Figure 7-8. A8 Switch Matrix PCA cont Service Manual5700A/5720A Series Schematic Diagrams Figure 7-9. A9 Ohms Cal PCA 5700A-1631 Figure 7-9. A9 Ohms Cal PCA cont 5700A/5720A Series Service ManualFigure 7-9. A9 Ohms Cal PCA cont Schematic Diagrams Figure 7-9. A9 Ohms Cal PCA cont 5700A/5720A Series Figure 7-10. A10 Ohms Main PCA Figure 7-10. A10 Ohms Main PCA cont Schematic Diagrams Figure 7-10. A10 Ohms Main PCA 5700A/5720A Series Service ManualFigure 7-10. A10 Ohms Main PCA cont Schematic Diagrams Figure 7-11. A11 DAC PCA 5700A-7640 Figure 7-11. A11 DAC PCA cont C112 22uFR128 200K Schematic Diagrams 7-52 Schematic Diagrams Figure 7-11. A11 DAC PCA cont 5700A/5720A Series Figure 7-12. A11A1 DAC Filter SIP PCA Figure 7-13. A1142 DAC Buffered Reference SIP PCA 5700A-7650 Figure 7-14. A12 Oscillator Control PCA cont A 1 ARE BUSSED AND CONNECTED TO GND3 AT ONE POINT 4. C5 AND C55 ARE NOT INSTALLED3. ALL GND CONNECTIONS DENOTED WITH DG211 Schematic Diagrams 7-60 Figure 7-15. A13 Oscillator Output PCA Figure 7-15. A13 Oscillator Output PCA cont Schematic Diagrams Figure 7-15. A13 Oscillator Output PCA cont 5700A/5720A Series Figure 7-16. A13A1 Oscillator Wideband SMD PCA Figure 7-16. A13A1 Oscillator Wideband SMD PCA cont Figure 7-17. A14 High Voltage Control PCA 7-68 Figure 7-17. A14 High Voltage Control PCA cont Figure 7-17. A14 High Voltage Control PCA cont 5700A/5720A Series Service ManualFigure 7-17. A14 High Voltage Control PCA cont Schematic Diagrams Figure 7-18. A15 High Voltage/ High Current PCA 5700A-1660 Figure 7-18. A15 High Voltage/High Current PCA cont 5700A/5720A Series Figure 7-19. A16 Power Amplifier PCA 5700A-7670 Figure 7-19. A16 Power Amplifier PCA cont 4. NOT INSTALLED 10 M 2N4044 Figure 7-19. A16 Power Amplifier PCA cont 7-78 Figure 7-20. A16A1 Power Amplifier Digitial Control SIP PCA 7-80 Figure 7-20. A161A1 Power Amplifier DigitalControl SIP PCA cont 5700A-1680 Figure 7-21. A17 Regulator/Guard Crossing PCA Figure 7-21. A17 Regulator/Guard Crossing PCA cont Schematic Diagrams 5700A-7690 7-84Figure 7-22. A18 Filter/PA Supply PCA Figure 7-22. A18 Filter/PA Supply PCA cont 5700A/5720A Series Figure 7-23. A19 Digital Power Supply PCA Figure 7-23. A19 Digital Power Supply PCA cont Figure 7-24. A20 CPU PCA Figure 7-24. A20 CPU PCA cont Schematic Diagrams Figure 7-24. A20 CPU PCA cont 5700A/5720A Series Service ManualFigure 7-24. A20 CPU PCA cont Schematic Diagrams Figure 7-24. A20 CPU PCA cont 5700A/5720A Series Figure 7-25. A21 Real Panel PCA Figure 7-25. A21 Rear Panel PCA cont Schematic Diagrams Figure 7-25. A21 Rear Panel PCA cont 5700A/5720A Series Service ManualFigure 7-25. A21 Rear Panel PCA cont Schematic Diagrams Figure 7-25. A21 Rear Panel PCA cont 5700A/5720A Series Figure 7-26. Hybrids Figure 7-26. Hybrids cont Schematic Diagrams Figure 7-26. Hybrids cont 5700A/5720A Series Service ManualFigure 7-26. Hybrids cont Schematic Diagrams Figure 7-26. Hybrids cont Service Manual 5700A/5720A Series