Ive got this amp on the bench which warants repair. One rail cap vented so I replaced them all. I had the amp working briefly after that, but a few minutes into testing and now all the amp outputs is loud buzzes which are vaugly in relation to the frequency generator's input signal.
I found 0.050vDC on RCA shields so I proceeded to remove Q11 on the driver board. I found Q11 bad, but no other components. I replaced Q11, a 1D transistor: MMBTA42. There is no longer DC on RCA shields but the amp still produces massive distorion/buzz.
One more thing, if I increase te input signal strong enough, speaker outputs start to produce slight DC. Once ~2v hits, the amp goes into protection.
I found 0.050vDC on RCA shields so I proceeded to remove Q11 on the driver board. I found Q11 bad, but no other components. I replaced Q11, a 1D transistor: MMBTA42. There is no longer DC on RCA shields but the amp still produces massive distorion/buzz.
One more thing, if I increase te input signal strong enough, speaker outputs start to produce slight DC. Once ~2v hits, the amp goes into protection.
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