darn, I got to go houston, been putting it off, since we were making progress, I'll pick back up with you on monday. Thanks, I think we are getting somewhere!
Pulled up one leg of the diode got a forward drop of .555V and 0 on the multimeter for the other direction, so I think that is okay. So maybe the cap is shorting? What should I check for next?
The cap could be shorted and any of the muting transistors could be defective (shorted/leaking from the gate to the other terminals)
Success! I have sound!
one of the output transistors J108s was leaking, but not for one of the amplified channels. It was a transistor on the input board, that goes to the output rca's. I don't even use those outputs.
How could I have blown that?
All I can think of is maybe I didn't align the pin connector correctly for the input board and powered up sending a damaging signal, for example, the -13V is on pin 4, but pin 3 is +15, so could sending +15 to the jfet damage it?
Regardless, thank you so much for your help. Your webpage was very helpful, I think I'll be purchasing your full tutorial as well.
My next task will be fixing a pc2150, where the sound goes out from the left channel, and then mysteriously comes back. When it was occurring I swapped inputs and the outputs so I know it something internal to the amp. But I'll work on that much later.
Thanks again!
one of the output transistors J108s was leaking, but not for one of the amplified channels. It was a transistor on the input board, that goes to the output rca's. I don't even use those outputs.
How could I have blown that?
All I can think of is maybe I didn't align the pin connector correctly for the input board and powered up sending a damaging signal, for example, the -13V is on pin 4, but pin 3 is +15, so could sending +15 to the jfet damage it?
Regardless, thank you so much for your help. Your webpage was very helpful, I think I'll be purchasing your full tutorial as well.
My next task will be fixing a pc2150, where the sound goes out from the left channel, and then mysteriously comes back. When it was occurring I swapped inputs and the outputs so I know it something internal to the amp. But I'll work on that much later.
Thanks again!
The +15v would have damaged it if one of the other terminals was at ground.
The gate acts like a diode. Applying too much positive voltage causes excessive current flow which will cause it to fail.
The gate acts like a diode. Applying too much positive voltage causes excessive current flow which will cause it to fail.
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