I have a galaxy S4 (canadian version) and have only been having troubles with it within the last couple days. I do develop so I'm not new when it comes to phones but this issue has me at a lose.
When I make or receive a phone call there is absolutely no audio on my end, I cannot hear the dial tones or the other person's voice. The only thing I can here is the call connect and disconnect beeps. The person on the other end hears a very loud buzzing/white noise. This noise becomes intermittent slightly when I speak into the problematic device.
It is only when making/receiving a phone call that the audio does not work. All speakers are functioning in all other apps (music player/skype etc.) the mic is also working without a problem when used for other apps.
Attempts at Solutions:
Restarting the device (with headphone connected and without)
Factory resetting the device (with headphone connected and without)
Flashing updated (and older) stock firmware on to the device
Flashing custom ROMs on to the device
Making calls with headphone connected / speaker phone
All settings have been checked to ensure in call volume has not been disabled
Currently running: Gummy version M1.02-25-14-NIGHTLY (Please note that when the phone first started messing up I was running stock 4.2.2 and there was no audio during a call between either phone. The Gummy ROM has made some improvement)
Current android version: 4.4.2
Phone Model #: SGH-I337M (Canadian S4)
Baseband version: I337MVLUAMDJ
Any help is appreciated!