LG CM9530 - Page 37

3-18
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the PORT. IN FUNCTION, repair the set according to the
following guide.
6-4. IN THE PORT. IN FUNCTION
6-4-1. Solution
Please check and replace IC202 on MAIN board.
6-4-2. How to troubleshoot (Countermeasure)
1) Check PT_L/R signal from MIC/PTB board to MAIN board.
2) Check POT_L/R signals to IC202(Pin9, 10).
3) Check if ADC_BCK, ADC_LRCK, & DAC_MCLK are entered from IC501 to IC202.
4) Check if ADC_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.
5) Check the following I2S 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.
6) 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.
6-4-3. Service hint (Any picture / Remark)
0&6B0&/.WR5
0&6B/5&.WR5
0&6B%&.WR5
$'&0,&B'$7$WR
5
37%B5WR5
37%B/WR5
{T
IC501
MLC3700
IC600
TAS5548
PWM
DAC_BCK
DAC_LR CK
IC202
CS5346
POT. IN
ADC_DATADAC_MCLK
POT_L/R
MIC/PTB
Board
IR AMP
IRS2092+IRF6775
< Signal check point >
< PORT. IN function signal fl ow >