With Picture But No Sound; A Certain Channel Is Abnormal; No Picture On Av - Sanyo PDP-42XS1 Service Manual

3.With picture but no sound:

Check if the second pin of sound
power amplifier input the signal.
The sound power amplifier or peripheral
circuit has problem. Check power supply,
if the control of ENABLE pin is normal; if
output short-circuited or other problems
that causes protection to work.

4. A certain channel is abnormal

4.1 No picture on AV

Check if the video processing board X110 is output.
No
Yes
Check MSP3440 or
peripheral circuits.
Check if the pin 2 of
N708 has input signal.
No
Check the AV terminal
socket to N708 channel
Yes
No
Measure if the sound
input of current channel
of N101 is normal.
Yes
Check if the C228 has
the signal input.
Yes
No
Yes
Check the periphery circuit
of N708 and power supply
23
The sound damaged.
No
Check different levels of
circuit following input audio
signal channel.
Check periphery circuit of N201,
crystal and power supply