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Hey hello. I replaced my iPhone 7 display with a new one… and when I started the phone everything was working totally fine for 15 days. But after 15 days a message popped up—“TOUCH ID CANNOT BE USED ON THIS PHONE”—and assistive touch was turned on automatically. What should I do now? Should I replace the home button?
On the iPhone 7, a replacement Home button won’t do anything, it is for cosmetic purposes only. You may have lightly damaged the flex when you replaced the screen and the problem manifested itself only a few weeks later. There is a great Q&A on this subject here: iPhone 7 home button not working after screen replacement. See @rany’s answer for more guidance.