I have this phone for 1 year and 5 months and I never had this problem before.
What happens? Sometimes, all of a sudden, I try to receive/make calls and I can't hear the person.
The person is able to hear me, I am able to hear the person with earphones and speaker but not from the top speaker(receiver/dont know how it's called)..
The very first time it has ever happened, I was running CM 11 Snapshot.
I've found a temporary solution for this, whenever this happens, I dial *#0*# to reach the Samsung testing app, then I press the 'Receiver' button on the screen, and I hear the Receiver noice perfectly, and voi-la, I am able to hear the calls again. Everytime I do this procedure, the calls work properly and I can hear everything perfectly.
What I've made so far to try fixing it:
* Totally wipe data/cache.
* Flash custom ROMs
* Flash stock ROM
None of these worked.
I am totally curious about WHAT can be happening, it does NOT look like a hardware problem to me, do you have any suggestions before I ask someone to replace the phone? Is there any procedure I can automatically set the phone to make everytime I reboot it? (So I don't have to *#0*# everytime).
Thanks for your time
Android Version: 4.4.2