LG U990 Service Manual page 131

4. TROUBLE SHOOTING
4.12.4 Microphone for main MIC
Main Microphone path as below:
MIC → C567,C568 → MSM internal CODEC
C563
SPM0204HE5-PB-3
10u
P
4
G2
3
G1
2
O
1
MIC500
C575
MIC
33p
LGE Internal Use Only
MICBIAS
C564
47p
MIC1N
C567 22n
C569
NA
C568 22n
MIC1P
C576
10p
Start
Make a call
MIC_BIAS(R221) is 1.8V?
YES
make some sound or
voice to MIC
Can you scoping some
sound signal at C567,C568?
YES
Work well?
C200
10p
NO
Change the Main B'd
NO
Change the MIC or
Change the Main B'd
YES
END
Copyright © 2007 LG Electronics. Inc. All right reserved.
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C238 0.1u
Place near
10%
MSM pin W18
(CODEC VSS)
F25
SDCC_DAT1_GPIO99
M25
SDCC_DAT2_GPIO100
M26
SDCC_DAT3_GPIO101
Only for training and service purposes
MSM
MSM
MSM