LG U880 Service Manual page 115

4. TROUBLE SHOOTING
4.18.4 Microphone for Main MIC
Main Microphone path as below:
MIC -> C534,C535 -> MSM6250 -> MIC feed back gain logic -> MSM internal CODEC
SP0102BE3
5
G3
U505 4
PWR
3
G2
2
G1
1
OUT
C533
NA
Start
Make a call
MIC_BIAS(C537) is 1.8V
make some sound or
voice to MIC
Can you scoping some
sound signal at C534,C535
Change the Main B'd
MIC
MICBIAS
C538 C537
10u
47p
MIC1N
C536
0.022u C534
NA
0.022u C535
MIC1P
NO
YES
NO
YES
NO
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Change the Main B'd
Change the MIC
Work well?
Near to MSM
YES
END