Electrical Troubleshooting Guide; Power Supply On Main Board - LG BPM55 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER SUPPLY ON MAIN BOARD

No 3.3 V
Is the
Vcc supplied to D150
anode?
Is D150 output 5.1 VA?
Is there
signal at IC151
pin1?
Check IC151 and replace.
No 5 V
Is the
Vcc 5.3 VA supplied to IC150
pin27?
Is there
3.3 V at IC150
pin25?
Check IC150 and replace.
YES
YES
YES
YES
YES
YES
YES
NO
Check 5.1 VA on IC150 pin10.
NO
Check C178 or replace D150.
NO
Check voltage on IC501.
NO
Check 5.1 VA on IC150 pin10.
NO
Check PWR_CTL2 signal from IC501.
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