I don't know if these outputs are just shorting out on me during this process but your question about 506 caused me to revisit it. I discovered it shorted between all 3 legs. I know it wasn't in that condition before. The previous testing had Q504 unpopulated and all others populated. I replaced Q506 and inserted a replacement into Q504 and retested.
Q500/501 5.4v
Q502/503 4.0v
Q504/505 5.3v
Q506/507 4.0v
Q500/501 5.4v
Q502/503 4.0v
Q504/505 5.3v
Q506/507 4.0v
Reassembled and it powered up. Getting 115v at the bus bars near the outputs and 58v at the output terminal. Tested for audio at a low level and it is playing clean so far. There was some sparking that came from the ends of the resistors in between the 2 rows of capacitors, the 4R7 and 2R7 resistors, so I resoldered the ends as best as I could reach with the soldering iron. I will order some and change them. Also one of the capacitors next to them appears to have a bulging top so I will change that also. I will still insert an insulator under the green transformer winding.
Is there anything else I need to do to make sure the amplifier is fully repaired and reliable?
Is there anything else I need to do to make sure the amplifier is fully repaired and reliable?
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