I now see that vol is almost mute with equalizer [bass and treble] controls
flat or neg.
With equalizer set to max, vol is useable @ perhaps 80% power.
Does that help pinpoint the problem?

"John Keiser" wrote in message
news:48qdnVyu_aVeyq7TnZ2dnUVZ_qadnZ2d@powerusenet. com...
I've owned this receiver/amp for 30 years. Used infrequently but
functioned fine. Today, while playing a CD, suddenly stopped after 5
minutes on low setting. Toggled to mute, loudness, no joy. Using FM
input, controls seem to work and I can hear music when I reach very high
settings. Sometimes crackles to very loud but only momentary. I think
pre-amp is OK.
I'm thinking some sort of protective output circuit has activated but I
have no schematic. Before I tear in blindly, does anyone have access to a
schematic for this [I found a source on rapidshare but file no longer
there].
Thank you.