LG CM5660 Service Manual page 35

6. NO SOUND
There is no sound output in the TUNER function, repair the set according to the following guide.
6-5. TUNER FUNCTION
6-5-1. Solution
Please check and replace IC202 on MAIN board.
6-5-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from pin1, pin3 of TU200 to IC202 (pin9, pin10).
  If no signals, check DVCC_3.3V for tuner power.
  Check if the tuner control signals (CLK, DAT, CE, RST, SLT) are entered from IC500 to TU200.
If it doesn't work, replace TUNER with a new one.
2) Check if MCS_BCK, MCS_LRCK, & MCS_MCLK are entered from IC500 to IC202.
3) Check if ADC_DATA is entered from IC202 to IC500.
  If no signal, check DVCC_5V & DVCC_3.3V (ADC) for IC202. If is NG, replace it with a new one.
4) Check the following I2S audio signal flow from IC500 to IC700. (Refer to Item 6-1-2.)
  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 6-2.
  If AMP is damaged, replace it with a new one.
6-5-3. Service hint (Any picture/ Remark)
< TUNER function signal fl ow >
ONE POINT REPAIR GUIDE
DSP IC500
3-18
TUNER_L: pin9 TUNER_L: pin9
TUNER_R: pin10 TUNER_R: pin10
IC202 IC202
< MAIN board top view >