Iphone 4 audio issues. PLEASE HELP!

[heisdnice]

ok so what i have is an iphone 4 factory unlocked for T-Mobile on iOS 6.
my issue is when im getting/making calls the caller can sometimes hear me but mostly not. it works for a little bit then totally goes out and the weird part is i can still hear them no problem.
they've also told me that they hear static.
the REAL weird part is that using apps and stuff, my voice is picked up perfectly.
i dont understand.
i obviously did some googling before posting here and i believe my issue is the Audio IC issue? not 100%.
so my question is how can i fix this.
ive seen u might have to put something over this or something like that,
but i DO have another iphone 4 that broke the battery connector
so im assuming i can swap the bad part on this iphone for the good one on my broken iphone?
if so, what parts am i swapping?

thanks in advance, i am trying to be as explanatory as possible.

[iRevival]

I guess my first though would be to swap the microphone. If you tear them both down the part you need to switch is the charging port. That cable has the microphone built in. Switching those should fix the issue. Let me know if you need anymore info.

[heisdnice]

so apparently im not the only one with this issue as it seems tons of people are having the issue and fixed it with this simple fix:

How to fix the iPhone 4 (4s) Mic problem - YouTube

i tried it and it worked for a day, then now it stopped.
it seems when the phone is off if i press down on the screw holding in the battery connector, they can hear me.
i just need to know what part to swap out as i have a testing iphone that i can take the part from.

[iRevival]

See my first post.

[Cowboy]

+1