Microphone Trouble - LG GS290 Service Manual

4. TROUBLE SHOOTING
Check Speaker 's
No
Connect Speaker
Combination with PCB.
completely.
Yes
Input Signal is
No
Replace Main Board
Good(C364,C365
) ?
Yes
Output Signal is No
Replace Audio
High(C343,C342)
AMP(U304)
?
Yes
Assemble
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Only for training and service purposes

4.7 Microphone trouble

Check Points
-Microphone hole
-Mic. Bias & signal line
MIC
TP2
FB305
MAIN_MIC_P
BLM15AG121PN1
FB306
MAIN_MIC_N
BLM15AG121PN1
TP1
L303
VMIC_P
100n
C307 C322 C318
47p
27p 27p
VMIC_N
MIC101
Copyright © 2010 LG Electronics. Inc. All right reserved. - 75 -
Only for training and service purposes
4. TROUBLE SHOOTING
C373 22n
MIC300
1
OUT
C374 22n
2
G1
3
G2
4
G3
5
PWR
6
G4
SPM0410LR5H-QB
C314
VA300 VA302
1u
TP1
L303
TP2
FB305
FB306
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