Electrical Troubleshooting Guide; Power Supply On Smps Board - LG CMS8450F/W Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER SUPPLY ON SMPS BOARD

No output 5.6 VA
Is the F901 normal?
YES
Is BD901 normal?
YES
Is the VCC
(11 V ~ 25 V) supplied to IC901
pin4?
YES
Power line of MAIN PCB is short.
No 12 V
Is the
VCC 12 VA supplied to IC951
pin1?
YES
Is there
'H' signal at IC951
pin4?
YES
Check and replace IC951.
Or check line of PCB is short or not.
MAIN
NO
Replace F901 (same fuse).
NO
Replace BD901.
NO
Is D960/ D961 normal?
Check or replace D960/ D961.
NO
Check or replace D965.
NO
Check P_CTL from μ-com.
3-25