"Gary L. woodruff" wrote in message
...
Thanks Greg, I have been out of the repair end for a while (25 yrs) so
could you elaborate? I have checked the input signal of the channel and it
looks clean. I do see the distorted output right at the output of the
amplifier board.

Thanks, Gary

With faults like this, a good exercise is often to just compare channels
using a simple ohm meter. With the unit off, and the main PSU filter caps
fully discharged, just hook one lead to ground, and then probe corresponding
points between a working channel, and the one that's bad. If the amp that
you are working on has suffered blown output transistors, I would be looking
for open circuit series resistors in the bases of the output devices. They
are usually low value, and it's very common for them to fail when the
outputs do. Also, check the output transistor emitter resistors carefully.
Although they will usually fail open when the output devices blow, they can
also go high, which can be difficult to spot by just doing a cursory run
over them with your meter. When a nominal 0.02 ohm resistor has risen to 5
ohms, it still looks pretty much like a 'short', unless you check exactly
what the meter is saying, particularly if you are using an analogue one.

Arfa