Mic Trouble Shooting - LG KM500 Service Manual

4. Trouble Shooting

4.11 MIC Trouble Shooting

z MIC Operation scheme is shown below.
ICTLAC1
B9
ICTLAC2
D2
MICIN
D1
MICIP
C1 L100 100nH
HSMIC
E3
MICBIAS MICBIAS
E2
HSMICBIAS HSMICBIAS
C2
AUXI_FMR
D3
FML
G2
EARN RCV_N
G1
RCV_P
TP25_BB
MIC MIC
MICBIAS
C627
27p
C629
MIC_P
MIC_N
C630 0.1u
z MIC signal flow
- MIC is enable by MICBIAS
- MICBIAS Signal from ABB(U102).
- MICIN, MICIP signal from MIC(MIC600)
z Check Point
- MIC bias
- Audio Signal level of the Microphone
- Soldering of Components
LGE Internal Use Only
C111 27p
C154
100p
HSMICIP
C112
C113
100p 27p
TP26_BB
L603
0.1u
100nH C638
L604
27p
100nH
C632 C633
VA600
27p
27p
EVLC14S02050
C635
10u
C634
100p
MIC_ABB_N
MIC_ABB_P
MIC600
1
OUT
2
G1
3
G2
4
G3
5
PWR
6
G4
SPM0204LE5-QB
Copyright © 2008 LG Electronics. Inc. All right reserved.
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TP26_BB
TP25_BB
Only for training and service purposes