Teac A-R650 MK2 Repair (Audio Tutorial)

Fault 1
Amplifier in protection mode power LED flashing RED.
Left channel Audio Output transistors short circuit.
Sanken
Q518 - 2SC3519A & Q520 - 2SA1386A
Resistors replaced
R533 100 Ohm ¼ W
Emitter Resistors R539 / R538 0.22 Ohm 5 W
Bias for each channel set to 5 millivolts.
Fault 2
Intermittent loss of sound, flexing the Volume Control / Pre-Amp board restore correct operation.
Common issue caused by oxidisation on the multipin connector where the pins plug into the Tone / Micro Board.
Pins cleaned with a fibre glass pencil, ad De-Oxi sprayed into the socket.
Board removed and inserted a number of times to remove any oxidisation restoring correct operation.
Amplifier fully tested working correctly.
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