Introduction - Fluke 43B Service Manual

7.1 Introduction

This chapter describes troubleshooting procedures that can be used to isolate problems
with the test tool.
Opening the case may expose hazardous voltages. For example,
the voltage for the LCD back light fluorescent lamp is >400V!
Always disconnect the test tool from all voltage sources and
remove the batteries before opening the case. If repair of the
disassembled test tool under voltage is required, it shall be carried
out only by qualified personnel using customary precautions
against electric shock.
•
If the test tool fails, first verify that you are operating it correctly by reviewing the
operating instructions in the Users Manual.
•
When making measurements for fault finding, you can use the black COM input
banana jack, or the metal shielding on the Main PCA unit, as measurement ground.
•
To access the Main PCA for measurements, proceed as follows:
1. Remove the Main PCA unit, see 6.2.5.
2. Disassemble the Main PCA unit, see 6.3.
3. Connect the Display Assembly flat cable, the Backlight cable, and the Keypad
Foil flex cable to the Main PCA unit. Position the Keypad on the Keypad foil.
See Figure 7.1. The Test tool without the case is operative now.
4. Power the PCA via the Power Adapter and/or battery pack. Watch out for short
circuiting due to metal parts on your desk!!
Warning
Figure 7-1. Operative Test Tool without Case
Corrective Maintenance

7.1 Introduction

REPAIR3.BMP
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