LG CM8460 Service Manual page 45

10. NO SOUND
There is no sound output in the TUNER function, repair the set according to the following guide.
10-4. TUNER FUNCTION
10-4-1. Solution
Replace IC201, TU500 on MAIN board.
10-4-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_L/R is entered from pin1 & pin3 of TU500 to IC201 (pin26, 27).
  If no signals, check +3.3 V for tuner power.
  Check if the tuner control signals (CLK, DAT, CE, RST, GPO2) are entered from IC501 to TU500.
If it doesn't work, replace TUNER with a new one.
2) Check if ADC_BCK, ADC_LRCK & DAC_MCLK are entered from IC501 to IC201.
3) Check if ADC_DATA is entered from IC201 to IC501.
  If no signal, check +5 V & +3.3 V (ADC) for IC201. If is NG, replace it a new one.
4) Check the following I2S audio signal flow from IC501 to IC202.
  If there is any trouble, check the power for each IC. The power is normal but, if the signal waveform to
the IC is distorted or no signal, replace it with a new one.
5) Check if the digital audio AMP block is okay.
  If AMP is damaged, replace it with a new one.
10-4-3. Service hint (Any picture/ Remark)
TUNER_L/ R
IC201
CS5346
ADC/
MCS_MCLK
MIC_DATA
MCS_BCK
IC501
MCS_LRCK
MLC3730
MIX_DATA_OUT
< TUNER function signal fl ow diagram >
ONE POINT REPAIR GUIDE
TUNER
Jack
Board
IR AMP
IRS2092
IC202
+
PS9860
IRF6775
PWM
ADC/ MIC_DATA ADC/ MIC_DATA
MCS_BCK MCS_BCK
MCS_LRCK MCS_LRCK
MCS_MCLK MCS_MCLK
< MAIN board bottom view >
3-22
TUNER_R to pin27 TUNER_R to pin27
TUNER_L to pin26 TUNER_L to pin26
IC201 IC201