Audio Trouble Shooting - LG KU800 Service Manual

4. TROUBLE SHOOTING

4.19 Audio Trouble Shooting

4.19.1 Receiver Path
Voice Receiver path as below:
MSM6275 Ear1ON/Ear1OP → R500,R501 → U500(Speaker/receiver switch) →
CN501(b'd to b'd connector for LCD Module) → LCD b'd to b'd connector of LCD FPCB →
LCD module → Speaker
Connect the phone to network
Equipment and setup call
Start
Setup 1KHz tone out
Hear the tone to the receiver
NO
The sine wave appear at
R500 , R501
YES
The sine wave appear at
VA500, VA501?
YES
The sine wave appear at
Speaker soldering point?
YES
Change the speaker
Can you hear the tone?
YES
END
NO
Change the Main board
NO
Check U500
Check connector pin and
NO
Speaker soldering point.
Or Change the LCD FPCB
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