ProSound 1600 Power Amplifier Repair

Описание: Fault
Temperature fault indication LED on.

The ProSound 1600 Amplifier is modular in design so relatively straight forward to repair.

Initial inspection of the Amplifier showed an attempt had been made to repair the Amplifier, sadly causing additional damage.

The Main Amplifier board was disconnected from the power supply PCB.

The plus and minus 68 volt supply was checked and the negative rail was missing. Fixing screws removed, please note the ground lead must be taped up to prevent it accidently touching the 3 pin DC connector on the power supply which would discharge the capacitors,

It was clear this is what had happened, and resulted in the PCB track being burnt off the board near to the 3 pin DC connector.

Burnt out track repaired and the power supply PCB refitted, DC checked and the negative supply rail was not present.
Also the speaker protection relays changed over and the over Temperature fault light turned off. (Correct operation)

The main Amplifier PCB / Module was removed and checks made the following components had to be replaced

Q1, Q9,Q2 2SC5200 & Q11, Q10, Q3 2SA1943
Q20,Q16 2SA940, Q15, Q21 2SC2073
Q8 2SD669A.
R52 0R2 5 Watt, R62, R51, R50, R63, R67, R68 4R7 1/4 Watt.

Amplifier fully tested correct operation