Why doesn't my Galaxy S4 have no audio during calls but works fine on Bluetooth and on internet calls?

[MUGZ85]

Galaxy S4 has no audio during calls - Works fine on bluetooth and via internet calls.

Hi guys,

I have a bit of a unique problem with my Galaxy S4. I've seen somewhat similar issues in other threads, but none with a solution, and incorrect assumptions that it must be hardware, so I'm hoping we can figure it out.

The S4 works perfectly outside of a call. However, if I make a call, there is no volume whatsoever - I don't hear the ringing, I don't hear the other person, and they can't hear me. Likewise if the person calls me, I can't hear anything. However, if I use a bluetooth headset, it works perfectly fine. Equally as frustrating, if I call via Skype or Facebook Messenger using the phone, it works fine using the phone normally, which uses all of the same hardware that a normal call would use. I can also play music and all system sounds work without issue.

To fix the issue, I've attempted to format it, which made no difference whatsover. Then, I tried flashing it with a stock rom, which I downloaded from SamMobile.com, using Odin, and no change. What DID work, at least temporarily, is clearing the system cache. The funny thing is, that it only works for about a minute or two, and it doesn't work every single time I do it, but it usually does: I'll clear the system cache, reboot, and it will work perfectly for a call or two (and will always work as long as I continue the first call if it's not interrupted), and then it will go back to what it was doing. Then, I'll clear the system cache again, and it will either do nothing, or work for a similar amount of time. I don't know if the phone is downloading something in the meantime that's causing it, but I haven't logged in with my Google Account, so it's not an app or any 3rd party thing that I've installed. What exactly is clearing the system cache removing when I clear it, and what is my phone auto downloading? Would this be a problem with my service provider or with Samsung? It's obviously not hardware, as it works perfect after I clear the cache, so warranty shouldn't be an issue.

I'm at a complete loss as to where to go from here. If you have any ideas, please post and let me know. I'm willing to give anything a shot at this point. Thanks in advance

 

[Golfdriver97]

Re: Galaxy S4 has no audio during calls - Works fine on bluetooth and via internet calls.

I am almost tempted to say it might be an issue with the modem. You should be able to flash an earlier version modem to you phone in a similar way that you flashed a stock ROM. What I am not sure is, if the older modem will be compatible with the newer ROM.

 

[Rukbat]

Re: Galaxy S4 has no audio during calls - Works fine on bluetooth and via internet calls.

The only problem with flashing the modem is that if you don't have a current modem to flash it back to, and flashing the earlier one doesn't fix it, the warranty is void.

My take on a phone in warranty that has a problem you can't solve by pressing a few buttons (figuratively and literally) - and I was in the cellphone business for years - is bring it back and if they can't fix it, they'll replace it. It might be an interesting educational exercize to discover what's causing the problem, but if a warrantied phone has a problem, it's ultimately the manufacturer's problem. You shouldn't be wasting too much time and/or effort to fix it. (Just make sure that everything (even files you think you probably won't ever need again) is backed up to another couple of devices (even a couple of cloud accounts). Storage is cheaper than irreplaceable data.