LG FH6 Service Manual page 44

ELECTRICAL TROUBLESHOOTING GUIDE
POWER SUPPLY ON MAIN BOARD
No 5 V (USB)
Is the VCC supplied to IC306 pin1?
Is there signal at IC306 pin3?
Check IC306 and replace.
YES
YES
YES
NO
Check 5 V output of IC305.
NO
Check IC501 pin22 (USB_PCTRL).
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