Electrical Troubleshooting Guide; Power(Smps) Circuit - LG LST-5600A Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. Power(SMPS) CIRCUIT

No 3.8VA
YES
NO
Is the F101
Normal?
YES
NO
Is the BD101
Normal?
YES
NO
Is the R107
Normal?
YES
NO
Is Vcc (14V-22V) sup-
plied to IC101 Pin3?
YES
NO
Are the D121
normal?
NO
Is there about 2.5V
at the IC103 Pin1?
YES
NO
Is the D124
normal?
YES
NO
Is the D125
Normal?
YES
NO
Is the D129
Normal?
YES
NO
Is the D126
Normal?
YES
Power Line of Main
PCB is short
Replace the FR101
(Use the same ICW)
Replace the
BD101
Replace the R107
NO
Is the D102
normal?
Replace the D121
Replace the IC103
Replace the D124
Replace the D125
Replace the D129
Replace the D126
3-2
Check or Replace
the D102