LG GT540 Service Manual page 126

4.12.5. Microphone for headset
MIC for Head_Set path as below:
Insert Headset Interrupt which are the signal of Headset detecting arise in EAR_SENSE
MIC BIAS(PMIC_R506 : 1.6V~1.8V(MIC BIAS) -> MIC signal -> FB504 ->
-> C256 -> MSM7227
Insert Headset & Make a call
Make some sound or voice to MIC
Can you scoping some sound
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
START
Yes
TP1(C259) is 1.6~1.8V?
Yes
signal at TP2(FB504)?
Yes
Work well?
Yes
END
No
Change the Main board
No
Change the Main board
- 127 -
4. Trouble Shooting
LGE Internal Use Only