LG -D175F Service Manual page 127

Check Main Mic hole.
Check FB6920 and MIC_Bias level (R6622)
MIC_BIAS_1
MIC_IN1_N
FB6920
MIC_IN1_P
LGE Internal Use Only
1800
Rev.1.0
1005 -> 0603(DR)
GND Close to MIC
MIC6920
C6920
DNI
C6921
33p
C6703 33p
0.1u
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3. TROUBLE SHOOTING
R6622
Rev.1.0
DNI
Dual only
0603 change
6
G4
5
PWR
4
G3
3
G2
2 MIC6920
G1
1
OUT
0903_change 0903_change
R6623
Rev.1.0
DNI
Only for training and service purposes
single only
6
G4
5
PWR
4
G3
3
G2
2 MIC6921
G1
1
OUT