LG CK57 Service Manual page 54

ELECTRICAL TROUBLESHOOTING GUIDE
POWER (SMPS)
No PVDD
YES
F901 normal?
YES
BD901 normal?
YES
TH901(TH903) normal?
YES
Is Vcc
(10 V ~ 18 V) supplied to
IC911 Pin4?
YES
Q901 normal?
YES
D951 normal?
YES
Is there about 2.5 V
at IC951 pin1?
YES
Power line of main PCB is short.
NO
Replace F901 (Use the same fuse).
NO
Replace BD901.
NO
Replace TH901.
NO
D903 normal?
YES
Q911 base HIGH?
YES
Check or replace Q911.
NO
Replace Q901.
NO
Replace D951.
NO
Replace IC951.
3-17
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Check or replace D903.
• Check P_CTRL HIGH signal from MCS.
• Check PC902.
Only for training and service purposes.
NO
NO