LG CM9530 - Page 38

3-19
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the TUNER FUNCTION, repair the set according to the
following guide.
6-5. IN THE TUNER FUNCTION
6-5-1. Solution
Please check and replace IC202, TU101 on MAIN board.
6-5-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from Pin1 & 3 of TU101 to IC202(Pin23, 24).
 If no signals, Check +3.3 V for Tuner power.
 Check if the Tuner control signals (CLK, DAT, CE, RST, GPO2) are entered from IC101 to TU101.
If it doesn’t work, replace TUNER with a new one.
2) Check if MCS_BCK, MCS_LRCK, & MCS_MCLK are entered from IC501 to IC202.
3) Check if ADC/MIC_DATA is entered from IC202 to IC501.
 If no signal, check +5 V & +3.3 V(ADC) for IC202. If is NG, replace it a new one.
4) Check the following I2S audio signal flow from IC501 to IC600. (Refer to Item 6-1.)
 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.
 If AMP is damaged, replace it with a new one.
6-5-3. Service hint (Any picture / Remark)
0&6B0&/.WR5
0&6B/5&.WR5
0&6B%&.WR5
$'&0,&B'$7$WR
5
781(5B5WR&
781(5B5WR&
{T
IC501
MLC3700
IC600
TAS5548
PWM
DAC_BCK
DAC_LRCK
IC202
CS5346
TUNER
ADC_DATADAC_MCLK
TUNER_L/R
IR AMP
IRS2092+IRF6775
< Signal check point >
< TUNER function signal fl ow >