LG GX300 Service Manual page 110

CHECKING FLOW
SETTING : After initialize Agilent 8960, Test EGSM900, DCS mode ( or PCS mode )
Make a phone call,
then check TP1 mic bias signal
comes from U102?
YES
Check the signal
Level at each side of MIC200.
Is it a few tens
mV AC?
YES
Check the soldering of
TP2, TP3
YES
Microphone will work
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Only for training and service purposes
START
NO
properly.
2. TROUBLE SHOOTING
NO
1. Check mic Bias signal line
2. Change the U102
Change the MIC200 &
U203 & U204
NO
Resolder component
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4. TROUBLE SHOOTING
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