LG KU950 Service Manual page 124

4.17.4. Microphone for main MIC
Main Microphone path as below:
MIC → C104,C105 → MSM6275A → MIC feed back gain logic → MSM internal CODEC
C102
10u
SP0204LE5-PB
G3
5
PWR
C104
4
G2
3
G1
C105
2
OUT
1
MIC100
R116
NA
R117
C107 C108
MIC
0 33p 10p
R118
NA
C109
NA
Make a call
MIC_BIAS(C102) is 1.8V
make some sound or
voice to MIC
Can you scoping some
sound signal at C104,C105
Can you scoping some
sound signal at C307,C308
Change the Main B'd
MICBIAS
C103
47p
MIC1N
22n
C106
NA
22n
MIC1P
Start
NO
YES
NO
NO
YES
NO
4. TROUBLE SHOOTING
Change the Main B'd
Change the sub-key PCB
Change the MIC
Work well?
- 125 -
C300
10p
C307 C308 C309
NA NA NA
C314
0.1u
Near to MSM
F25
SDCC_DAT1_GPIO99
M25
SDCC_DAT2_GPIO100
M26
SDCC_DAT3_GPIO101
AE3
MDP_VSYNC_SECONDA_GPIO104
AD2 R315 NA
MDP_VSYNC_PRIMARY_GPIO105
YES
END