LG OM5541 Service Manual page 29

ELECTRICAL TROUBLESHOOTIHG GUIDE
No 12 V
YES
Is Vcc (15 V)
supplied to IC931?
YES
IC931 Pin4 "H"?
YES
Check or replace IC931.
No VFD
YES
D931 normal?
YES
ZD931 normal?
YES
Q501 / Q502 normal?
YES
Check or replace VFD.
NO
Check or replace D935.
NO
Check the 'P.CTL "H"' signal from μ-com
NO
Check or replace D931.
NO
Check or replace ZD931.
NO
Check or replace Q501 / Q502.
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