LG MCD206 Service Manual page 23

ELECTRICAL TROUBLESHOOTING GUIDE
USB abnormal
YES
Check U802
YES
pin16,87 "DAC_BCK",
pin80,88" DAC_LRCK",
pin83 "DAC_DATA"
data signal.
NO
Check YES
U802 pin111, 112
signal.
NO
Check TX802, U802.
Check R826,R881,
R888,R886,R883.
Check U804
YES
pin37 "DRM_CKE"
signal.
NO
Check U804.
3-8
Check U802
YES
pin116 "USB_D+",
pin117 "USB_D-"
signal.
NO
Check PN804
YES
pin2 "USB_D-",
pin3 "USB_D+"
signal.
NO
YES
Check PN804
pin4 "+5 V".
NO
Check U809.
Normal.
Check FB12, FB13.
Check USB connector.