"Alan Liefting" wrote in message
...
Got a Technics SA-EH600 home theater system with a fault. The display
comes up when first powered up from the mains but when the power/standby
button is pushed it says "GOOD-BYE".

The relay that activates the +/- supplies for the output stage never
activates. Did a basic check for shorts and opens but nothing was was
obvious.

Any ideas?


Alan Liefting


Blown channel. DC offset. Power supply issues. The usual. One can jumper the
power relay contacts and bring the unit up on a variac, then look for DC
offsets or excess current draw. Alternatively, one can use a double-ended
POLARIZED power cord plugged into the switched AC outlet on the rear, and
connect that to the variac. If there is a second switched outlet on the
receiver, plug it's own power cord into that one - this would ensure that
the microprocessor and smaller sub-supplies are energized.
Might be a good idea to put a smaller main fuse in there or substitute a 100
watt lamp for the fuse. Then if there's a hard short, the lamp will alert
you by glowing bright. A dull glow after initial charging of the power
supply caps is normal.


Mark Z.