LG CM9750 - Page 49

3-30
ELECTRICAL TROUBLESHOOTING GUIDE
USB FUNCTION
Replace IC312.
NO
IC312 USB Power
+5 VU OK?
YES
A
A
When insert USB,
IC501 pin U7, U8, A7, A8
USB_D signal OK?
NO
YES
YES
YES
YES
AUX FUNCTION
Check audio cable.
Replace IC201.
Check IC501.
NO
NO
NO
IC201
pin23, 24 AUX input signal
OK?
IC201
pin41 ADC_DATA_IN output
signal OK?
IC201
pin42, 43, 44 I2S input signal
OK?