On the ones where the Light comes on but nobody's home
These amps used capacitors from the "Plague" years. Millions of part failures on Stereos , power supplies and flat screen TVs
Replace the main power supply caps . ONe of them is a 470UF at 100 volts
Dont remember the other.
Also , check the DC ohms on the speaker Somewhere between 4-8 ohms?
|Klipsch Synergy Sub 10 Subwoofer Speaker|