Chosen Solution
Hey, yesterday replaced whole screen + lcd for my iphone 6 from a donor phone, changed the button as well. Yesterday phone worked like a charm, as well as touch id. But today, touch id randomly stopped working and shows notification, button functionality remained. Any ideas whats the issue? For me it`s very strange, that at first it worked as normal, but just randomly stopped working…
There is no signature problem “fingerprint sensor just stopped working” So you are left with the common problems that always lead to no fingerprint sensor—-you tore the long flex cable or have a bad one, have water damage in the home button connector, or have pry damage or poor connection at the logic board. Troubleshoot these with a different long flex and take a look under the microscope.
You may have damaged the Home Button flex (the one on the button) or the Home Button Link flex (the one that runs underneath the LCD heat shield) while replacing the screen. The damage may have been minimal but enough to eventually stop working. Open up the phone and take a close look at the flexes and their connectors to see if there is any damage or tears. The Link Flex can be replaced.
