LG FH6 Service Manual page 41

ELECTRICAL TROUBLESHOOTING GUIDE
2. POWER SUPPLY ON MAIN BOARD
No 3.3 V
YES
Is the
VCC supplied to IC304
pin3?
YES
Is there
signal at IC304
pin2 ?
YES
Check IC304 and replace.
No 3.3 VA
YES
Is the
VCC supplied to IC303
pin3?
YES
Check IC303 and replace.
NO
Is D302 normal?
Are D301 & D304
normal?
Check 5.5 VA on SMPS board.
NO
Check IC501 pin150
(PWR_CTRL).
NO
Are D301 & D304
normal?
Check 5.5 VA on SMPS board.
3-22
NO
YES
NO
YES
NO
YES
Check or replace D302.
Check or replace D301 & D304.
Check or replace D301 & D304.