I'm trying to fix this set in the customer's home and have reached an
impasse.
There is line output present, and Var. output as well from the RCA
jacks in the back but just a hum from one of the speakers, with the
other speaker dead quiet, This occurred after a lightning storm.
I Have left and right signals at the dual shielded cable to the audio
board so it appears that everything prior to this board must be OK.
Power supply voltages as marked on W4 of the audio board are OK. In
signal tracing the output chip, a TA8200AH I found that there is hum on
one input, and nothing on the other just like the speakers. There is no
VCC to the output chip VCC point and no short to ground. There does
however appear to be VCC present on one of the inputs to the chip,
which would account for the hum probably.
I've pulled the board but really at this point though, I need to see
the schematic for this unit in order to go any further.
Does anyone have a copy they would be willing to share. I'd really like
to try to fix this one.
The audio board bears the following markings:
ANP1190-C
AWV1030-B
YG-P870094V
ANC1280-B, (this one is stamped on the rear metal plate with the VAR
jacks, Surround Bal. control, and Surround processor on/off switch)
Thanks for any assistance. Lenny Stein, Barlen Electronics.