Well, to everyone here following the saga of this thread,
the Onkyo amplifier muting problem now seems solved.

Many details exist, but basically I got the rc transmitter
from the original plastic bag, dug up some AA batteries,
re-plugged the components rc cables, and started push-
ing buttons.

Not really much happened at first. Interestingly, the amp
has a huge volume knob right in the middle of the front
panel. Testing the rc volume +/- activates some kind of
small motor that actually advances/retards the knob. g

But, on to the real problem. I couldn't even find the muting
button on the rc unit at first. Unlike the other buttons, it's
printed in red on the black background. Being color blind
I had to resort to one of those lighted magnifiers made for
old people. g

Pushing the mute button did easily disable the status on the amp's display.
However, power cycling the amp,
seems to guarantee initialization in mute mode. But, now
that I can disable this, that's ok. Again, I now have the
full amplificaton restored.

Thanks again, to everyone that forced me to explore all
possibilities. I held little optimism for this last diagnosis,
but I was certainly proven wrong.

Thanks,

Gary