Re: 7704A Vertical Amplifier Issues


Mark Vincent
 

Barry,

I was wrong about the 2N2222A being a sub. The original is a PNP. My mistake.

The voltages would be best checked with the transistor and resistors replaced. Testing the output IC from the base to collectors can be done now. One end of the meter to where the 33 ohm connects and the other end of the meter to each plate. That will tell if that part of the output transistors will be good. That is not a conclusive test for the output IC. Replace the parts. See if the 33 ohm resistor gets warm. If it gets hot/burns again, the IC is the problem.

Mark

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