I have a Sony STR-D390 receiver -- circa 1992, digital tuner, drives 2 pair speakers, has remote -- that (1) produces no sound except a very slight hiss/buzz at full volume, (2) does not display "stereo" on startup when in tuner mode tuned to an FM-stereo station and (3) has a dead tiny red light in its motorized volume control knob.
All these symptoms began as an intermittent annoyance a few months ago, always curable with a light tap or two on the chassis, then not-so-light taps, then a couple good whacks, then hitting on it so hard the "logical" next step was a sledgehammer. Good thing I don't have one.
Disconnecting everything and taking off the cover and gently poking around I can find nothing obviously wrong -- solder joints look OK, no loose components or broken wires or loose connectors. Does anyone out there have any insights as to what the most likely problems would be and what a fix would involve?
I have an old multitester and there are repair manuals available on line but my skill/knowledge level got maxed out when they used vacuum tubes you could take out and test at Radio Shack. Repair by Sony at their flat rate would cost almost as much as buying a newer unit, and I'm trying to gather what info I can before deciding to take it in for repair locally or replacing it.
Thanks in advance from southern Wisconsin.