Chosen Solution
Here’s a strange one. The kid broke her screen for the 5th time, but this time she seems to have killed something a screen replacement didn’t help. When making a CELL call neither party can hear the other. There’s just dead air. If I flex the phone slightly I can get static and sometimes even hear the call as normal. Eventually it dies again. The mic and both speakers are fine. I can record memos and playback voicemails. Facetime calls work. 4G Internet and Wifi are fine. I restored the phone to factory settings with no luck. This HAS to be a hardware problem, especially since flexing the phone physically is a temporary fix. Could an antenna be loose? Could a cable be bad? Which connections should I check? The guide here only talks about WIFI antennas and cables. Thanks!
You would be right thinking this would be a hardware problem. These symptoms point to the baseband CPU. This chip has voice data lines which run to the audio IC. The baseband CPU is also on the fault line of an iPhone 6. A decent drop could crack a a pad under the chip that’s why when you flex the phone it comes good sometimes. I don’t recommend reflowing chips but this would be an exception. But honestly I would be putting the money towards a new phone.
