If I remember correctly, there's a small electrolytic cap in the
mains detection section of the speaker protection circuit which goes
open circuit. It's maybe 1uF or 10uF... years since I worked on those.
I don't know why the unit would shut down after a few hours though.
Good luck with it.

Cheers,
Bob


wrote:

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