Bad idea suggesting this person adjust his own amp with no training or test
equipment.

Yamaha's trigger at about 1.2 volts. If there's this much offset, the amp
needs service - period.

The problem could be a bad cap in the feedback circuit, we've seen this
before.

Mark Z.
Authorized Yamaha servicer


"Carroll Conklin" wrote in message
...
This is not quite a tube issue but I think I can help you. The offset
voltage adjust is set to borderline operation. i.e. there is approximately
50mV at one of the speaker outputs. Yamaha had two pots per channel for
adjustment. One was for idle current and the other for this offset adjust.

Your speaker protection circuit is sensing this offset and turning on and
off depending how bad it is.

Carroll
wrote in message
oups.com...
I have a Yamaha R-900 Receiver that has worked flawlessly up until
about a week ago.

About one out of four times that I switch it "on" the protective
circuit relay does not engage.

Also, if I leave it on for several hours, the receiver will shut down.
Any suggestions?

Thanks,

Mark