LG MICRO Hi-Fi SYSTEM Service Manual page 29

3. USB PART
TURN ON USB
"Searching" or
"USB" display check
Reading ok check
OK
YES
YES
YES
NO
Check the power supply circuit
Check the HRST#signal
Check the HRST#signal
check the usb part and dvd part line
NO
Check the usb jack power supply
Check the usb data line
Check the ES8391
check data line pin111(USB-No) 110(USB-Po)
3-16
(Check CN201)
YES
YES
(Check CN201)
YES
(CN201)
YES