IPhone 4 can't hear when someone calls?

IPhone 4 can't hear when someone calls?

Put volume high

Try turning off the phone and turn it back on. It could be a software issue.

Most likely the same problem I had. Turned out to be the audio I/c. If you're not good at reballing or sm soldering look at the easy fix on YouTube. But make sure you look up I/c audio problems not just the normal one. This quick fix should incorporate completely disassembling the logic board. Not just an l shape paper on the dock connector