LG CMS4540F/W - Page 38

No 12 V
Is Vcc (15 V)
supplied to IC931?
Check or replace D935.
YES
YES
NO
IC931 Pin4 “H”?
Check P-CTRL “H” signal
from MCS.
YES
NO
Check or replace IC931.
No VFD
D931 normal?
Check or replace D931.
YES
YES
NO
ZD931 normal?
Q501 / Q502 normal?
Check or replace ZD931.
Check or replace Q501 / Q502.
YES
YES
NO
NO
Check or replace VFD.
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AUDIO ELECTRICAL TROUBLESHOOTIHG GUIDE