I have a Soundesign stereo console from the 70's or 80's (not sure, but it has AM/FM, Cassette, and 8-track) that hums. Even though it is powered off, there is an audible humming noise coming from the stereo console. It has an LED digital clock. Could that be the source? Is there a capacitor at fault, and how do I track it down?
I don't want to get rid of it because it is my only source for 8-track tape playback.