LG OK99 Service Manual page 46

NO SOUND
There is no sound output in the TUNER function, repair the set according to the following guide.
10-3. TUNER FUNCTION
10-3-1. Solution
Replace IC301, IC302 on MAIN board.
10-3-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from pin13 &14 of IC302 to IC301(pin27, 28).
 If no signals, check AVCC_3.3V for Tuner power.
 Check if the Tuner control signals (CLK, DAT, CE, RST) are entered from IC501 to IC302.
If it doesn't work, replace IC302 with a new one.
2) Check if DSPI_BCK, DSPI_LRCK & DSPI_MCLK are entered from IC501 to IC301.
3) Check if ADC_DATA is entered from IC301 to IC501.
 If no signal, check DVCC_3.3V & AVCC_3.3V(ADC) for IC301. If is NG, replace it a new one.
4) Check the following I2S audio signal flow from IC501 to IC601.
  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.
 If AMP is damaged, replace it with a new one.
10-3-3. Service hint (Any picture / Remark)
T-
TUNER_L/R
IC301
ADC_DATA
DSPI_MCLK
MCS_BCK
IC501
MCS_LRCK
MIX_DATA_OUT
< TUNER function signal fl ow >
ONE POINT REPAIR GUIDE
IC302
TUNER
IC601
IR AMP
PWM
IC301 IC301
TUNER_L to pin27 TUNER_L to pin27
TUNER_R to pin28 TUNER_R to pin28
< MAIN board bottom view >
3-21
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IC601 IC601
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