Fluke 5220A 4-21

Maintenance

Troubleshooting

4

4-21

Table 4-6. Mainframe and Digital Section Troubleshooting Guide

Step Instruction Yes No Go to

1 Set the 5220A POWER switch to OFF and disconnect the unit from line

power.

2

2 Remove the top cover and the large inner cover from the 5220A. 3

3 Visually inspect the internal fuses (F2 through F7) and replace as

required.

4

4 Connect a shorting jumper between the front panel VOLTAGE INPUT

terminals.

5

5 Check to ensure that all PCB assemblies are securely installed in the

correct locations. See Figure 4-1.

6

6 Determine the enabled output terminals by visually identifying the

position of the front/rear output jumper screws. Tighten these screws if

they are loose.

7

7 Connect a shorting jumper between the enabled output terminals. 8

8 Connect the 5220A to line power and set the POWER switch to ON. 9

9 Is the fan running? 13 10

10 Are any of the front panel LEDs lit? 11 12

11 Loose fan connections or defective fan. Repair as required. 8

12 Check the line power fuse and replace if necessary. If fuse continues to

blow, locate short in input power circuit/transformer assembly. Check

the position of the line voltage switches on the transformer assembly.

Using a dc voltmeter, verify the presence of all power supply voltages

at the A4 Regulator PCB and the A3 Cap Bus. Test points are provided

on the A4 Regulator PCB. Measure the A3 Cap Bus outputs (±12 V dc)

at the bus bar terminals on that assembly with respect to COM 2 (the

ground plane on top of the A3 Cap Bus PCB).

Voltage Test Points Limits

Hi Lo

A4 Regulator

+15 V 3 5 +14.4 V to +15.6 V dc

-15 V 7 5 -15.6 V to –14.4 V dc

+5 V ISO 1 2 +4.8 V to +5.2 V dc

+5 V 6 4 +4.8 V to +5.2 V dc

A3 Cap Bus

+12 V - - +10.5 V to +13.5 V dc

13

- 12 V - - -12.5 V to –10.5 V dc

14 Are all voltages within limits? 16 15

Contents

Main Page Table of Contents 5220A Page Page List of Tables Page List of Figures 5220A Page Page Section 1 Introduction and Specifications 1-1. Introduction 1-2 1-2. Specifications Specifications for the Model 5220A are given in Table 1-2. Introduction and Specifications Specifications 1-3 1-4 Page Page Section 2 Operating Instructions 2-1. Introduction 2-2. Shipping Information 2-3. Input Power 2-4. Fuse Replacement 2-5. AC Line Fuse 2-6. Power Supply Fuses 2-7. Rack Installation 2-8. Operating Features Page 5220A 2-4 2-9. Operating Notes 2-10. AC Line Connection 2-11. Transconductance Amplifier 2-12. Input Voltage Requirements 2-13. Input Voltage Selection, Front/ Rear 2-14. Current Output, Front/Rear 2-15. Standby/Operate 2-16. Local/Remote 2-17. Status Indicators 2-18. Audible Output 2-19. Inductive Loads Page 2-20. Operation Page Section 3 Theory of Operation 3-1. Introduction 3-2 . Overall Functi onal Descri ption 3-3. General 3-4. Analog Section Page Page 3-5. Digit al Section 3-6. Circuit Analysis 3-7. Power Supply Page 3-8. Preamplifier 3-9. A6 Driver Page 3-10. A7 Output 3-11. A8 Analog Control 3-12. A9 Front Panel 3-13. A10 Logic 3-14. Reset Logic Page 3-15. Timing Logic 3-16. Standby/Operate Logic 3-17. Local/Remote Logic 3-18. Front/Rear I nput Logic 3-19. Failure Status Logic 3-20. A11 MIS Bus Interface Page Page Section 4 Maintenance 4-1. Introduction WWarning 4-2. Service Information 4-3. General Maintenance 4-4. Cleaning 4-5. Air Filter Maintenance 4-6. Access Information Page 4-7. Internal Components/Assemblies 4-8. Front Panel Removal 4-9. A9 Front Panel PCB Removal 4-10. A2 Transformer Assembly Removal 4-11. A6 Driver and A7 Output Assembly Removal 4-12. A3 Cap Bus Removal 4-13. A12 Shunt Assembly Removal 4-14. Fuse Replacement 4-15. Ac Line Fuse 4-16. Power Supply Fuses 4-17. Line Voltage Selection 4-18. Output Terminal Selection, Front/Rear 4-19. Service Tools 4-20. Performance Test 4-21. Initi al Conditions 4-22. Front Panel Tests 4-23. Zero Output 4-24. DC Accuracy and Line Regulation 4-25. Harmonic Distortion 4-26. Frequency Response 4-27. Overcurrent Trip Test 4-28. Overvoltage Trip Test 4-29. Calibration Adjustments 4-30. Initi al Conditions 4-31. Input Offs et Adjustment 4-32. Driver Offset Adjustment 4-33. Output Bias Adjustment 4-34. DC Accuracy Adjustment 4-35. Frequency Response 4-36. Overcurrent Adjustment 4-37. Overvoltage Adjustment 4-38. Replacement of Selecte d Components 4-39. Resistors R11 and R12 4-40. Resistor R13 4-41. Troubleshooting h Page Page 4-21 4-22 Note The jumper wire must be installed between the enabled output terminals. 4-23 Page 4-25 4-26 Section 5 List of Replaceable Parts 5-1. Introduction 5-2. How to Obtain Parts 5-3 . Manual St atus Information 5-4. Newer Instruments 5-5. Service Centers W Page Page 5-5 5-6 5-7 Page Page Page Page Page Page Page Page Page 5-17 5-18 5-19 Page 5-21 Page 5-23 5-24 Page 5-26 5-27 5-28 h Indicates a static-sensit ive part. Page Page 5-31 Page 5-33 Page Page Page Page 5-38 Note The A12 shunt assembly is a suggested non-repairable assembly. Page 5-40 5-41 Page Section 6 Option and Accessory Information 6-1. Introduction 6-2. Accessories 6-3. Rack Mounting Kit (M08-205-600) Page 6-4. Rack Slide Kit (M00-280-610) 6-5. Precision Y5020A Current Shunt