Оригинальный сообщение: Robert G ,
I also had this issue, and the microphone didn't worked, on receiving and placing calls. Buth using Viber/Voice Notes/Skype/etc worked flawlessly. What i did, I cleaned both microphones mesh holes, bottom and the top small hole besides headphone jack (this one was obstructed by grease or dirt, i used a brush and cleaned gentle inside it). I already had changed the Dock/Microphone flex before this (which didn't fixed the issue). I unscrew and screw again the top screws, leaving them not so tight, also cleaned the flex connector of the dock, with a soft brush and isopropylic alcohol. (i gave it a full brush all around the iPhone, removing dirt around it.) After all this and a couple of test call, the issue was gone! :D Let me know if it worked for you!