LG OM7560, Service Manual

Page: 37 / 76

3-18
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. TUNER FUNCTION
6-5-1. Solution
Replace IC201 on MAIN board.
6-5-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from pin1, 3 of TU500 to IC201 (pin26, 27).
 If no signals, check DVCC_3.3V 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 DVCC_5V & DVCC_3.3V (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 6-2.)
 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 6-1.

If AMP is damaged, replace it with a new one.
6-5-3. Service hint (Any picture/ Remark)
< TUNER function signal fl ow > < MAIN board bottom view >
TUNER_L: pin26 TUNER_L: pin26
TUNER_R: pin27 TUNER_R: pin27
IC201 IC201