I bought a Fisher 500C at an estate sale. The guy there said if was working earlier in the day but was not when I arrived. It was plugged in. Got it home and brought it up slowly on a variac, but no sound at all. Approximately .7 amps at 120volts. No sound from aux, radio, or tape in. Did not test phono. The on/off does not shut off. Is it possible that it was working and someone jacked the volume knob around and killed it? I'd love to get this working someday. Any thoughts from the Fisher team would be appreciated.