Hello all...
Another TV followed me home, this time a Zenith SF2023 model, made in 1989. (The service number is SF2023H2.) The previous owner must have taken perfect care of it--the thing is immaculate. And the picture quality is excellent--focus is good, brightness and contrast also have more than enough range. I even got the remote and it works.
But there's no sound coming out of this TV, and it "knows" this as it says "muted" all the time. Pressing the MUTE button has no visible effect. Pressing the volume buttons (either way) will cause the MUTED message to disappear for a split second. I can hear some crackling in the speaker when the TV comes on or turns off. If I put my ear up to it, I can hear a faint hiss from the speaker, but nothing that sounds even faintly like a TV program, even when tinkering with the volume controls.
The speaker is hooked up and tests good. The audio functionality in this TV appears to be centered on a daughtercard mounted near the rear of the mainboard. There's not much on this board--a capacitor, some "other stuff" and a Philips integrated audio amplifier (of unknown type--haven't looked yet) is it.
Any ideas? I've already checked for any speaker switches (found none), tried the "master reset" command in the menu (seems to affect the picture only) and gave the TV a good "shakedown" test to see if I could find cold solder joints (it didn't change behavior in any way).
William