Sound - LG CJ87 Service Manual

NO SOUND
There is no sound output in the PORT. IN function, repair the set according to the following guide.
9-2. PORT. IN FUNCTION
9-2-1. Solution
Replace IC200 on MAIN board.
9-2-2. How to troubleshoot (Countermeasure)
1) Check PT_L/ R signal from FRONT board to MAIN board.
2) Check if PT_L/ R is entered pin1 & pin3 of CN201.
3) Check PT_L/R signals to IC201(pin9, pin10).
4) Check if ADC_BCK, ADC_LRCK & DAC_MCLK are entered from IC501 to IC201.
5) Check if ADC_DATA is entered from IC201 to IC501.
  If no signal, check +5 V & +3.3 V(ADC) for IC201. If is NG, replace it a new one.
6) Check the following I2S signal flow from IC501 to IC202.
  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.
7) Check if the digital audio AMP block is okay.
  If AMP is damaged, replace it with a new one.
9-2-3. Service hint (Any picture/ Remark)
T-
POT_L/R
IC200
MCS_MCLK ADC_DATA
MCS_BCK
IC501
MCS_LRCK
MIX_DATA_OUT
< PORT. IN function signal fl ow diagram >
ONE POINT REPAIR GUIDE
POT. IN
Front
Board
IC600
IR AMP
PWM
IC200 IC200
PTB_L to pin21 PTB_L to pin21
PTB_R to pin22 PTB_R to pin22
< MAIN board top view >
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