LG CMS4540F/W Service Manual page 34

NO SOUND
There is no sound output in the TUNER FUNCTION, repair the set according to the
following guide.
5-5. IN THE TUNER FUNCTION
5-5-1. Solution
Please check and replace IC201, TU500 on MAIN board.
5-5-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from Pin1, 3 of TU500 to IC201(Pin26, 27).
If no signals, check +3.3 V for tuner power.
Check if the tuner control signals (CLK, DAT, CE, RST, SLT) are entered from IC501 to TU500.
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 IC201.
3) 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 with a new one.
4) Check the following I2S audio signal flow from IC501 to IC601. (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.
5) Check if the digital audio AMP block is okay. Refer to "Digital Audio AMP" guide on Item 5-2.
If AMP is damaged, replace it with a new one.
5-5-3. Service hint (Any picture / Remark)
TUNER
TUNER_L/R
A
CS5346
12.288MHZ
PWM
TAS5548
< TUNER IN function signal fl ow >
ONE POINT REPAIR GUIDE
DSP IC501
MLC3730
176PIN BGA
IC201
FR,FL
TAS5612LA
Woofer
TAS5612LA
TUNER L to C214
< Signal check point >
3-15
TUNER R to C215