Chosen Solution
Good evening to you all, I made the change from a window iphone 6 plus and also the flex dock and also the earpiece and the microphone does not work, the room is new. I do not know what to think of the problem is.
Check the microphone and earpiece gasket / filters, maybe they are clogged with dust, the hole right next to the earphone jack and the earpiece speaker filter. Do they make audible sounds then tapping and do not make noise when trying to speak or hear from them?
There isn’t a whole lot that could cause this. As Ben said, its almost certainly the top microphone that is bad. iFixit has a guide on how to change it. Its a very cheap and easy repair to do.
