My iPhone 6 fingerprint doesn't work,saying touch ID fail
Yes , had the battery replaced last week at the apple store then the touch sensor did not work, apple changed the screen free of charge as they damaged it
Reset Touch ID and try again.
If the problem persists, back up your iPhone, the reset the iPhone and try again with the touch ID.
If it still doesn’t work it needs to be repaired. It’s either the touch ID button itself or the logic board.