LG OM4560 Service Manual page 32

NO SOUND
There is no sound output in the TUNER FUNCTION, repair the set according to the following guide.
5-5. IN THE TUNER FUNCTION
5-5-1. Solution
Please check and replace IC200, IC202 on MAIN board.
5-5-2. How to troubleshoot (Countermeasure)
5-5-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from Pin13, 14 of IC200 to IC202(Pin11, 12).
  If no signals, check +3.3 V for tuner power.
  Check if the tuner control signals (CLK, DAT, CE, RST, SLT) are entered from IC502 to IC200.
If it doesn't work, replace TUNER with a new one.
2) Check if MCS_BCK, MCS_LRCK, & MCS_MCLK are entered from IC502 to IC202.
3) Check if ADC_DATA is entered from IC202 to IC502.
  If no signal, check +5 V & +3.3 V(ADC) for IC202. If is NG, replace it with a new one.
4) Check the following I2S audio signal flow from IC502 to IC700. (Refer to Item 5-1.)
  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. Refer to "Digital Audio AMP" guide on Item 5-2.
  If AMP is damaged, replace it with a new one.
5-5-3. Service hint (Any picture/ Remark)
ONE POINT REPAIR GUIDE
3-15
< TUNER IN function signal fl ow >
< Signal check point >