Note 3 Phone Audio Won't Work Unless Connected to Bluetooth

[AC Question]

For the past several months, my Note 3 will not function as a phone (incoming or outgoing audio) unless it is connected to a Bluetooth device (my car, headset, etc.). That is, no one can hear me, and I cannot hear anyone. I do hear the noise of touching the numbers on the dialpad, but then nothing after that (not even the "connect" noise).

I have tried turning off Bluetooth, unpairing existing devices, turning the phone off, trying speakerphone or non-Bluetooth headphones, etc. The ONLY thing that has helped to fix this temporarily is to completely take the battery out for 30 seconds and then reboot the phone--simply rebooting the phone doesn't do it. Since my phone is encrypted due to work policy, it takes 5 minutes to reboot, so this isn't a great solution. The audio will work for calls usually after doing this, but only for a short time, usually until it connects to a Bluetooth device again.

No other applications have any issues with audio.

I don't know if it has anything to do with it, but this started happening after I had a rental car and paired with Bluetooth in it. I removed the pairing right after turning in the rental. I'm not sure if the two are connected or not.

Sprint was less than helpful--they just tried to sell me a new phone.

Web searches haven't come up with anything since they just lead to troubleshooting Bluetooth not working.

Any ideas? Thanks!

 

[Rukbat]

A few ideas, none too helpful for you.

Check the earpiece, earphone jack and audio output. If one of those goes, you have no audio except by Bluetooth.

If the speaker works, just not on phone calls, you probably need a new motherboard. (You can buy a gently used Note 4 for less.)

If it's a Bluetooth issue, you'll need more equipment than you've ever seen - you have to know what the Bluetooth transmitter is saying, and what the phone's Bluetooth receiver is hearing.

Best bet? A fully equipped shop with spare motherboards and curiosity. If swapping in another motherboard fixes it, that was the problem.