LG CK57 Service Manual page 55

ELECTRICAL TROUBLESHOOTING GUIDE
POWER (SMPS)
No 12 V
Is Vcc (15 V)
supplied to IC931?
IC931 Pin4 "H"?
Check or replace IC931.
No VFD
D931 normal?
ZD931 normal?
Q301 / Q302 normal?
Check or replace VFD.
YES
YES
YES
YES
YES
YES
YES
NO
Check or replace D935.
NO
Check P-CTRL "H" signal from MCS.
NO
Check or replace D931.
NO
Check or replace ZD931.
NO
Check or replace Q301 / Q302.
3-18
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