4. TROUBLE SHOOTING
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LGE Internal Use Only
Copyright © 01 LG Electronics. Inc. All right reserved.
Only for training and service purposes
SETTING : After initialize Agilent 8960, Test EGSM900, DCS mode ( or GSM850, PCS mode )
START
Make a phone call,
then check C30(TP1) mic bias
comes from U01?
1. Check mic Bias signal line
. Change the U01
No
Yes
Microphone will work
properly.
Check the signal
Level at each side
of MIC501.
Is it a few tens
mV AC?
Yes
Change the microphone
No
Check the soldering of
C53, C59(TP5,6)
Re-solder component
No
Check microphone sound hole
Yes