LG CM9520, Service Manual

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3-31
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the IPOD FUNCTION, repair the set according to the fol-
lowing guide.
6-5. IN THE IPOD FUNCTION
6-5-1. Solution
Please check and replace IC201, IC202, IC203 on MAIN board.
6-5-2. How to troubleshoot (Countermeasure)
1) Check USB VBUS_+5V to Pin3 of CN201 after inserting the iPod to IPOD Docking System.
If no power, check if IPOD_P_CTRL to Pin3 of IC203 change Low to High.
2) Check if IPOD Audio L/R signals are entered from Pin11 & 12 of CN201 to Pin10 & 6 of IC201.
3) Check if the IPOD Audio L/R that some noise is removed to IC201 are output from Pin1 & 5 of IC201.
If no signal, replace the IC with a new one.
4) Check IPOD_L/R signals from pin1 & 5 of IC201 to IC202(pin26, 27).
5) Check if ADC_BCK, ADC_LRCK & DAC_MCLK are entered from IC501 to IC202.
6) Check if ADC_DATA is entered from IC202 to IC501.
If there is no signal, check +5 V & +3.3 V(ADC) for IC202. If is NG, replace it a new one.
7) Check the following I2S signal flow from IC501 to IC602. (Refer to Item 5-1.)
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.
8) Check if the digital audio AMP block is okay. Refer to “Digital Audio AMP” guide on Item 6-3.
If an AMP is damaged, replace it with a new one
6-5-3. Service hint (Any picture / Remark)
pwvk†sG›–GyY]X
pwvk†yG›–GyY]W
hkj†ijrG›–GyYX]
hkj†syjrG›–GyYX`
hkj†tjsrG›–GyYYX
pjYWY
hkj†kh{hGG›–GyYX\
{T
iPod
{T
IC501
MLC3700
IC602
PS9854
PWM
IC801
FS503B
BEAT BOX
AMP IC
TAS5631
DAC_BCK
DAC_LRCK
IC202
CS5346
DAC_DATA DAC_MCLK
ADC_DATA DAC_MCLK
IPOD_L/R
BEAT_DATA
< Signal check point >
< iPod function signal fl ow >