Hello,

I'm trying to service this unit (I have three units with the same problem)
and the -B supply for the pre-drivers starts out at -59 (+59 is ok) and then
right before the spk relay closes the voltage drops to -31 volts.

I did trace it to the overload protect circuit. The schematic states it's
the -B switch. One of the pre drivers gets very warm. The unit does not go
into protect mode.

The outputs check out. At this point, I don't know if it is the 7v line or
if it is one of the pre drivers pulling it down after a few seconds.

Any ideas?

Thanks