LG CM5660 Service Manual page 41

ELECTRICAL TROUBLESHOOTING GUIDE
No LED
YES
+12 VA is normal
to the Q105 Emitter?
YES
Is LED_5V & VFD_12V is normal?
YES
Check or replace Q302.
No VFD
YES
VFD_12V is normal?
YES
DVCC_3.3V & LED_5V is normal?
YES
VFD_CLK, STB, DAT is normal?
YES
Check or replace VFD.
NO
Check SMPS circuits.
NO
Check or replace IC101, Q105.
NO
Check or replace Q105.
NO
Check or replace IC103, IC101.
NO
Check or replace R311, R312, R313.
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