Here are some troubleshooting tips that helped me repair 2 units. Some I got from Sencore and others I found myself.
Faulty cap values and no response when trying to zero leads:
Check for pulse entering digital (bottom) board at pin 11 and leaving at pin 7
Pulse should change when Caps Value button is pressed
Check for shorted or open transistors TR20 and TR21 (2N5771) on digital board
If TR20 is shorted the pulse will be only partial level
Follow pulse through system to look for bad gates
Check IC12 pin 12 for 200hz square wave
Inductor test problems:
Check for 20 volts DC at pin 20 of board interconnect
Check for open series pass transistor TR11 (2N4401) on analog (top) board
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Tim
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