I have a pile PTA 44BT amplifier and the protection relays are vibrating at turn on for about 7 seconds then they stop vibrating. There is audio output. The problem occurs even with the speakers disconnected. Does someone have a schematic or can tell me what to check for in the unit to stop the vibration of the relays. By vibration I mean the relays are turning on and off like about 10 times per second for about 7 seconds then stopping.

 

I'm guessing that the voltage I checked rising from 0 to 11 volts is the one that goes to the relay. The relays are 12 volts and when the voltage rises to six volts it engages. It looks like the protection circuit is tightly fitted on the circuit board and hard to measure voltages with the probe of the multimeter. Now it's taking close to a minute to settle to on State