Have the same problem. There is no sound on incoming calls. There is also no sound on Youtube while picture is coming along fine. The local Apple support dealer says it is a hardware problem and the solution is to replace the phone!! Can't believe. Anyone can help?

...

Thanks.

It is really helpful, my phone back to normal after I remove and put back the SIM card!!

Thanks expert.

I work for a repair company and what I found that worked with this problem is replacing the charge port which also includes the microphone and port for the home button to plug into all on the same ribbon.

No sound only during phone calls??

kindly help me Apple

I made an account just to say this. If you have a brand spankin new phone and can hear everything and every call on it and control the volume just fine but on phone calls they cannot hear you....tAKE THE PLASTIC OFF. If you haven't already of course. I was freaking out then had the biggest 'duhh' moment of my life when i took it off. **This is only for those with this specific problem and the new plastic films still on their phone.**

Everyone, I think I know what's going on here.  It has to do with the internal wiring.  Something inside the phone is either shorting to ground or it doesn't have a good ground.  (Forget the cleaning routine; these people are likely just twisting their phones while cleaning them.)

To test the theory, start a phone call.  During the phone call and with the volume all the way up, grab the phone by both ends and give it a little twist.  It should immediately work!  Stop at this point because you know that the phone has a problem.

Now you could open it up as in https://www.youtube.com/watch?v=oAAda5Xj3-s for example.  You would need a very small and specialized screwdriver that's compatible with these phones.  IFIXIT makes this P5 pentalobe for a few dollars.  You might, however, take your phone into an Apple store, show them this forum thread and suggest that many, many iPhones appear to have a systemic problem that they need to fix.

Actually, I think what's happening is that you're opening the phone up, taking things apart and putting it back together as the real fix.  Next time, try simply twisting the phone along its length during a phone call—it will suddenly start working again.  You're looking at an internal/systemic wiring problem in the phone.

me to

no sound when I make calls only