If, for whatever reasons, Galaxy Note 4 finger scanner refuses to accept your fingerprints, you can still unlock the phone through one of the two methods:
•Use the alternative password (backup password). On the lock screen, you can tap the keyboard icon to type the backup password to unlock the screen.
•Use Android device manager to unlock the phone with your Google account.
Please note, your Google account can only unlock the phone. It cannot reset the backup password for Galaxy Note 4 finger scanner.
If I forget the backup password for Galaxy Note 4 finger scanner, how to reset it?
If you forget the backup password (alternative password) for finger scanner, you can reset it with one of the following 3 methods.
•Use your fingerprints. If your fingerprints are recognized, you can go to Settings–Finger scanner – change backup password to reset the backup password by authenticating yourself with your fingerprints.
•De-register all fingerprints. Of course, this also requires that your fingerprints are recognized. In fingerprint manager, you can delete all fingerprints. Once all fingerprints are de-registered, the Galaxy Note 4 finger scanner is reset. You can register your fingerprints again and setup a new backup password.
•Factory data reset. If you forget the backup password and none of your fingerprints are recognized by the Galaxy Note 4 finger scanner, you probably have to reset the phone. This essentially erase all your data and settings on Galaxy Note 4. So, you should always backup your data before resetting.