LG S75A1-D - Amp; Pwm

2-25
ELECTRICAL TROUBLESHOOTING GUIDE
3. AMP / PWM
Set turns on
but there is no sound.
YES
YES
NO
YES
YES
Check the connection
of CN803 & CN804.
PVDD should be
25 V (C7038).
PWM data
should be shown.
(R612, R613)
NO
NO
NO
Replace IC601.
GVDD should be
12 V (R7014).
Pin3 of IC601
should be high
(R614).
YES
YES
NO
Connect CN803 & CN804.
Replace IC307.
Replace X600.
Check micom (IC100).
Check adaptor.
Replace IC600.
Check power.
L601 should be 3.3 V.
Pin3 of IC307
should be 5.3 VA.
NO
NO
YESYES
YES
Check micom (IC100).
Pin2 of IC307
should be high (R338)
NO
YES
YES
Replace IC600.
Check Oscillation
24.576 MHz (R601).
PWR_RST should
be high (R604).
NO
NO