Electrical Troubleshooting Guide; Smps Board - LG SB95TX-S Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. SMPS BOARD

No power
Check the AC
line pattern
YES
Check fuse F901
YES
Check C976
voltage (3.9 V)
YES
Check C963
voltage (5.6 V)
YES
Check IC901
Vcc voltage (10 V ~ 30 V)
YES
Replace SMPS board
NO
Connect the open line
NO
Replace F901
Check BD901 "+"
to "-" pin impedance
NO
Check 3.7 V lines short
Replace PC972, IC902's components
NO
Check SMPS second part lines short
Check MAIN or AMP board short
NO
Replace PC951, PC972, IC901
Check around IC901's components
(Short, Open)
2-68
Low impedance:
Replace IC901, BD901