With jumper removed I'm getting -5.5v on pin 5 of the opto-coupler.
All 3 of the muting transistor are still out of the board.
Can you attach a pic showing me the location of the 1M resistor and capacitor?
Voltage reading on the square pad of the front two muting transistor is 0.0v. Voltage on the one by the transformer is -5.5v.
All 3 of the muting transistor are still out of the board.
Can you attach a pic showing me the location of the 1M resistor and capacitor?
Voltage reading on the square pad of the front two muting transistor is 0.0v. Voltage on the one by the transformer is -5.5v.
Your guess is as good as mine. When I lifted the leg before it dropped to -21.0v almost immediately. That was prior to cleaning the part of the board with the suspect trace. After that is when it started working in reverse voltage was at -17.5v but after a few minutes of play it rose to -2.5v. The voltage since then has not dropped below -6.5v.
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The voltage readings I'm getting are/have been inconsistent. The DC voltage at the junction of the diode and the 100k resistor is -8.4v. At the same time the reading on the 4 pin of the opto-coupler is -9.2v. Note: when I touch the probe to the leg of the opto-coupler -9.2v is the initial reading, if I hold the probe there the voltage rises.
Yes, I'm still using the RCA shield as a ground reference.
Yes, I'm still using the RCA shield as a ground reference.
We covered just about everything. You'll have to go back and redo the tests. Start by lifting the end of the 100k that's not connected to the diode. Does that allow the -20v to develop?
If so, recheck the board for leakage/electrolyte contamination by running one prove over the top of the board with the other probe grounded.
If so, recheck the board for leakage/electrolyte contamination by running one prove over the top of the board with the other probe grounded.
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