I would say, that event new iPhone is not really waterproof, sad but true. If someone taked off old adhesive, and put new, original one on the frame, it should have some kind of protection, but if i open iph for customers i always say, that will never be safe to use it under water, even if im using original adhesives.
Most likely it’s nothing than a damaged screen, thos line are normal for damaged screen, the reconection with motherboard will chang nothing, or there is possibility of cracked pin in phone connector, but this thing is the best check on another lcd.
If You used your iPhone under water, then its normal, and will not repaired under warranty. If your phone wasnt under water, then give it to apple, but ask only for screen replacement, not an whole phone.
1. Do you have Original Apple Cable ? 2. Did You try to enter into DFU Mode while connecting iP to Comp 3. Did You Tried to connect Your phone with Comp when screen is pluuged off ? 4. I can suggest You to connect it to another fully working CPU, sometimes it help 5. Was it Your first screen replacement ?
Hello. In my opinion it's not volume flex damaged. But ive got questions for You : 1) Does your phone getting lag when trying to rec a video, or trying to watch any video with sound on YT 2) Does Phone lag while some1 calling you, when you have sounds turn on , and does he works properly when you have sounds off ? When phone works properly on headphones You could have damaged sound IC, it's very expensive in repair, and very dangerous, beacause its "under" screen connections on Mainboard.
Everything is possible, but You have to project your own iOS, lightning flex, and PROBABLY new paths on maiboard :) You can do it, it only depends of that, how rich you are, and how smart people you will ask for this.
i Can't stand posts when someone asking someone to connect water damaged phone to any kind of voltage... After Water Damage, You have to turn off Your phone, do not try to charge or any factory reset. Only thing what you do is bring Your iPhone to any kind of service, which have an ultrasonic bath, and after the process of cleaning logic board with IPA, and ofcorse drying Logic Board, you can try to turn it ON iPhone IS NOT WATERPROOF in that sense what people thing, it's only commercial.