A black screen with a red LED light may appear. Keep holding until you see the “BlackBerry” logo with a progress bar.
Ensure the device is powered off completely. how to reset blackberry 10 os to factory settings
Once completed, the phone will restart and show the initial setup screen, just like when it was new. Use this if the phone is stuck on the logo, won’t start, or you forgot the password. A black screen with a red LED light may appear
Release the volume keys. The device will enter Factory OS Recovery Mode and automatically reinstall the factory OS. how to reset blackberry 10 os to factory settings
Tap Security Wipe .
Enter your device password if prompted.