LG GW620 Servise Manual page 150

4.13.5. Microphone for headset
MIC for Head_Set path as below:
Insert Headset Interrupt which are the signal of Headset detecting arise in EAR_SENSE
U21's
MIC BIAS LDO
-> C90 -> MSM7200A
make some sound or
Can you scoping some
sound signal at TP2?
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Only for training and service purposes
R12(RES) : 1.6V~1.8V(MIC BIAS)
Start
Insert Headset
& Make a call
YES
TP1 is 1.6~1.8V ?
YES
voice to MIC
YES
Work well?
MIC signal
NO
Change the Main b'd
NO
Change the Main b'd
YES
END
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4. TROUBLE SHOOTING
FB1
LGE Internal Use Only