Chosen Solution
i got my friend’s iphone 6, which had its screen broken and the frame kind of bend. and its home button was missing. for a long time it was in the drawer, because of error 53. Today, when i finally put ios 921, it restored completely. After i put everything back, screen seems to work fine, for a while, then suddenly the touch is gone. I rebooted the phone, adjust the lcd connector, sometime the touch will come back, some time it will not. but even if touch comes back, it goes away within a short time. If i leave it alone for a while, the touch will come back. but will be gone again. Any help will be great!
Replace the screen. The screen was probably severely damaged when it was dropped and the circuitry inside may be cracked or shorted somewhere.
