LG SoundPlate LAP340, Service Manual

Page: 29 / 55

3-4
ONE POINT REPAIR GUIDE
3-3. Service hint (Any picture / Remark)
3. NO AUDIO OUTPUT
3-1. Solution
Check audio out trace step by step.
3-2. How to troubleshoot (Countermeasure)
1) If audio DSP, optical input trace, BT input trace signal is normal, check below procedure.
2) Check power. IC701 Pin3, IC700 Pin2, IC601 Pin3.
3) Normal power output conditions
Ö Check IC705 analog output Pin9, 10, 1, 2, 3, 4, 33, 34, 35, 36.
4) Abnormal analog output conditions Ö Try replacing IC705.
5) After changing it, if the audio is still issued:
- Check line driver IC702, IC703, IC704’s block.
- Check volume IC IC709’s block.
- Check AMP IC IC706, IC707, IC708 block.
< Main board top view >
IC707
IC709
IC704
IC702
IC705
IC703
IC708 IC706