Mic. Trouble - LG G1500 Manual

4. TROUBLESHOOTING

4.9 Mic. Trouble

SETTING : After Initialize Agilent 8960, Test in EGSM, DCS Mode.
(PIF Power On. Test after Call 112)
voltage at Pin 3 of Q101
START
Check if the
C115 voltage is almost
2.2V(DC)
Yes
Is the
almost 0V (DC)?
Yes
Check the
signal level at each side
of MIC1. Is it a few
ten mV (AC)?
Yes
Check
the soldering of R105,
R106, C120, C124,
L101, L102
Yes
Replace Main Board.
Mic will work properly.
No
Voltage at pin 24 of
U101 is 2.45V(DC)?
Yes
Replace the R101 & R103.
No
Replace Q101.
No
Replace the Microphone, MIC1.
No
Replace R105, R106, C120, C124, L101, L102
- 84 -
MIC Bias
voltage
No
Replace the
U101.