This Sony STR-AV970X powers up ok, relay clicks on, but there's no audio at
the speaker outputs. I don't have a schematic so the only information I've
been able to figure out is that the output transistors have no bias voltage
on them and consequently there is no bias current across the emitter
resistors. There are just the supply voltages coming into the collectors
which are +/- 51 volts. The low voltage supply is putting out +/-12 volts
and +5 volts at the regulator sources. Sitting in the middle of all this is
a dual voltage amplifier, an STK3102III, which I suspect may be faulty but I
was wondering if somebody could tell me where the low voltage supply enters
the mix in the power amplifier section.

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA