LG KU730 Service Manual page 113

4. TROUBLE SHOOTING
4.17.4 Microphone for Main MIC
Main Microphone path as below:
MIC -> C305,C306 -> MSM6275 -> MIC feed back gain logic -> MSM internal CODEC
MIC
1
2
SUMY0010512
Start
Make a call
MIC_BIAS(C307) is 1.8V
make some sound or
voice to MIC
Can you scoping some
sound signal at C305,C306
Change the Main B'd
2.2K R308
MICBIAS
22n C305
MIC1P
MIC1N
22n C306
C308 C309 C307
10u
NA NA
NO
YES
NO
YES
NO
Change the Main B'd
Change the MIC
Work well?
- 114 -
F25
SDCC_DAT1_GPIO99
M25
SDCC_DAT2_GPIO100
M26
SDCC_DAT3_GPIO101
AE3
MDP_VSYNC_SECONDA_GPIO104
AD2
MDP_VSYNC_PRIMARY_GPIO105
YES
END
C602
0.1u
10%