LG U880 Service Manual page 113

4. TROUBLE SHOOTING
4.18.3 Loud Speaker path(voice speaker phone, VT, multimedia play, etc)
Loud speaker path as below:
MSM6250 HPH_R, HPH_L -> C508,C509 -> R506,R507 -> U502,U503(amp) -> R500,R501,
R502,R503 -> CN600 -> LCD FPCB -> Speaker
Connect the phone to network
Equipment and setup call
Setup 1KHz tone out
Set phone with speaker Phone mode
Start
The sine wave appear at
C508,C509?
YES
The sine wave appear at
R506,R507?
YES
The sine wave appear at
R500,501,502,503?
YES
The sine wave appear at
Speaker side in FPCB
YES
Can you hear the tone?
YES
END
NO
Change the Main board
NO
Check C508,C509,R506,R507 or
Change the Main board
NO
Check U502,U503
NO
Check the connector or
Change the FPCB
NO
Change the speaker
- 114 -