j wrote in message
...
I'm trying to troubleshoot a 1980'2 era Nak receiver that has pushbutton
input switching via a microprocessor (can also be remote controlled). The
button lights don't work, and I get no input connections at all. Strange,
but the micro works, controlling the volume up and down. Also, the amp
works via the pre-out and power-in jumpers. Apparently, some aspect of the
switching (done via an analog switch IC) is screwed up. Anyone have ideas
on how to troubleshoot this?

What ident is the big an. sw. ?