54 General Troubleshooting Procedures

The Fluke 45 allows for some fault isolation using self-diagnostic routines and descriptive error codes. However, these features are somewhat limited and do not provide in-depth troubleshooting tools.

The Fluke 45 incorporates a semi-modular design; determining modules not related to a problem constitutes the first step in the troubleshooting process. Disconnect the Battery Option cable at the Main PCA. Disconnect the IEEE-488 Interface Option at P2 and P3 on the IEEE-488 Interface PCA. If either of these assemblies is causing the meter failure, refer to troubleshooting information in Chapters 7 and 8 (7 for the Battery Pack Option, 8 for the IEEE-488 Interface Option.)

Measuring the power supplies helps to isolate a problem further. Refer to Table 5-2 and Figure 5-1 for test point identification and readings. If power supply loading is suspected, disconnect the Display PCA at J4 on the Main PCA. If this action solves the loading problem, proceed to Display Assembly Troubleshooting elsewhere in this chapter. Otherwise, refer to Power Supply Troubleshooting.

If the power supplies appear good, check the E clock signal to determine whether the Main PCA or the Display PCA is causing the problem. A correct display depends on the E clock signal. Missing segments, intensified digits, a strobing display, or a blank display can be caused by a faulty E clock.

Use an oscilloscope to check for the E clock at microcomputer A1U6, pin 68. Look for a 921.6 kHz square wave that transitions from 0 to 5 V dc (VCC).

• If this signal is present, the problem is probably on the Display PCA. Refer to Display Assembly Troubleshooting elsewhere in this chapter.

• If the E clock is something other than a 921.6 kHz square wave, isolate the digital chapter of the Main PCA by disconnecting the Display PCA at J4. Then check the E clock again, and refer to Digital Troubleshooting elsewhere in this chapter for further problem isolation.

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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