LG H990ds Service Manual page 71

3. TROUBLE SHOOTING
3.13 Audio Main MIC
It's operating voice call(except speakerphone), voice recording, camcorder recording.
Checking Flow Image
Start
Check the MIC filter
And reconnect PCB
Hear the Voice
through the RCV
in loopback test ?
Yes Yes
No
Circuit Diagram
Change MIC
No
Yes
Change Main Board
End
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