LG KE520 Service Manual page 97

4. TROUBLE SHOOTING
z MIC Trouble
START
Voltage across L600
is about 2.5V?
YES
Check the signal
level at each side of MIC100.
Is it a few tens mVAC?
YES
Check the soldering of
C113,C114,C600,C601,L601,L602
change the Main Board
END
LGE Internal Use Only
NO
MICBIAS Voltage of U102
is about 2.5V?
Re-solder L600
NO
Replace MIC600
NO
Replace U102
Copyright © 2007 LG Electronics. Inc. All right reserved.
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NO
Replace U102
Only for training and service purposes