Microphone very faint while on calls or audio memos
A couple of day ago I changed the mainboard of my iphone 4 after finishing, I noticed that the Microphone was very faint, while on phone calls as well as making audio memos.
Putting logic board in another iPhone frame - Microphone works fine
Putting Microphone in another iPhone frame - Microphone works fine
Putting dock connector in another iPhone frame - Microphone works fine
Logic board is OK
Microphone is OK
Dock connector is OK
Question: Can the phone frame basically cause this issues of poor sound recognition??
External microphone works fine with headset or handsfree via loudspeaker.
I really don't know where the problem lies.
Is this a good question?