LG CM 9520 Series Service Manual page 71

ELECTRICAL TROUBLESHOOTING GUIDE
POT. IN
IC202
Pin21,22 POT. IN input signal
OK?
YES
IC202
Pin42,43,44 I2S input signal
OK?
YES
IC202
Pin41 ADC data output signal
OK?
YES
A
iPod
IC202
Pin26,27 iPod input signal
OK?
YES
IC202
Pin42,43,44 I2S input signal
OK?
YES
IC202
Pin41 ADC data output
signal OK?
YES
A
NO
Check MIC board.
NO
NO
IC203
NO
Pin4 USB_VBUS 5 V
OK?
NO
Check IC501.
NO
Replace IC202.
3-42
Check IC501.
Replace IC202.
NO
YES
Check USB_VBUS of IC203.