My Nokia 720 has frozen on the lock screen (on).

[WPCentral Question]

I have tried to press every button but nothing happens, can you please tell me why it has done this and give any advice to how I can fix it.

 

[sam6691]

It happened to me also, follow any of these methods...

1. Soft Reset:
hold the volume down + power button pressed until the phone vibrates and restarts
2. Hard Reset:
Switch off your phone
Press and hold Camera + Volume down + Power buttons until your phone vibrates
Once your phone starts vibrating, release power button but keep Camera + Volume down button pressed for more 5 seconds
3. Restore to Factory Settings:
If the above solution dose not solve the problem, then you can restore to factory default.
* Before doing this Backup all your data.
On the start screen, Go to Settings > about > reset your phone.
* If your Mobile Phone keeps restarting continuously and not even allowing you to enter inside, then you can do factory reset using the below Method.
4. Factory Reset:
1. Disconnect your phone from the charger.
2. Press and hold the volume down key and connect the charger. An exclamation mark (!) is shown on the screen.
3. Press the following keys in order: volume up -> volume down -> power -> volume down.
Your phone resets and boots up automatically. This may take several minutes.
Once your phone is restarted, you can restore the backup data.