LG CM8440 Series - Electrical Troubleshooting Guide

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ELECTRICAL TROUBLESHOOTING GUIDE
1. POWER SUPPLY ON SMPS BOARD
YES
YES
YES
YES
YES
No output 5.6 VA
No 12 V
Power line of MAIN PCB is short.
Replace F901 (same fuse).
Check or replace D962/ D963.
D960, D961 normal?
Replace BD901.
Check P_CTL from μ-com.
Check and replace IC951.
Or check line of MAIN PCB is short or not.
Check or replace D960, D961.
NO
NO
NO
NO
NO
F901 normal?
Is the
VCC 13 VA supplied to IC951
Pin1?
Is the VCC
(11 V ~ 25 V) supplied to IC901
Pin4?
BD901 normal?
Is there
‘H’ signal at IC951
Pin4?