LG -MC2670 Service Manual page 41

LG-MC2670
Checking Flow
SETTING : After initialize 5515C, Test US Cellular
START
Voltage at R440 = 1.2V?
(MIC BIAS Voltage Check)
Yes
Check the signal level
At each side of MIC. Is
It a few tens mVAC?
Yes
Check the soldering of
C450, C451
Yes
Check the soldering of
MIC Filter Part
Yes
MIC will work properly
No
Check the soldering
Of R440
Replace MSM
No
Replace the microphone
No
Re-solder C450, C451
No
Re-solder MIC Filter part
38
No
Re-solder R440
Yes