Chosen Solution
So I dropped my phone and it worked fine afterwards, then two days go by then all of the sudden when I try to call someone on FaceTime, my phone glitches and once the call connects the screen turns black & it says “reconnecting.” When I try to make phone calls, there’s no ringing and I am unable to hear whoever is on the other line whether I’m using headphones, putting the phone up to my ear, or putting it on speaker mode. When all of this was happening I was still able to play videos & listen to music, then last night after listening to music, all of my sounds disappeared. Now I can’t listen to anything and videos won’t even play. I have tried turning the phone on & off, but everytime I turn the phone off, it stays off and will loop on the Apple logo.
Chances are the audio chip on your phone has gone bad. Microsoldering is required to fix this problem. You may be able to find someone that does board level repairs from a reputable mobile phone shop that offers a no fix no fee model.
Like @benjamen50 said, this is a common failure on the iPhone 7/7+ and you need to find a reputed shop that will replace the audio Codec chip and reconnect as well broken traces underneath that chip. This last step is critical otherwise the phone will not be fixed or only temporarily - I say that because I’ve see some people only reflow or reball that Codec chip. Be sure to pull a back-up ASAP, and specially before having it opened for repair.
That does sound like a logic board problem. Unfortunately, Costs to fix such problems are usually close to–or more expensive than–replacing the phone. Have you considered selling the broken unit on ebay for parts and putting the profits towards a new/used phone? The market on ebay for broken devices is generally very attractive.
