Sanyo LCD-42XR7H Service Manual page 45

b) TPA3001
If audio
output (X12, X13)
If sound processing IC
has output (C27, C29)
Sound processing IC N03 and
its periphery has problem
The output of TPA3001 is differential output, so when check X12, X13 output signal with
oscilloscope, please use the power cord with two pins, otherwise, it may damage the audio
amplifier.
(4) a certain channel abnormal
a) AV no picture
NS02 or the periphery circuit
of AV input have problem
b) TV no picture
NS02 or the periphery circuit
of TV input have problem
amplifier
No
No
If X09 4# input
signal
Yes
If X09 4# input
signal
Yes
N04 emitter-follow circuit
and N07 has problem
Speaker
Yes
Audio amplifier and the circuit has problem.
Check the power supply, 6# MUTE. Turn on
again after power off and check if the audio
amplifier protection.
No
The path from AV terminal
to this socket has problem
No
If N04 12# of TV board has
output signal
Yes
43
No
TUNER01or the periphery of N04
has problem. The emphasis is power
supply.