The Nokia Lumia 925 may reboot or turn off on its own.
If you are experiencing reboot or device powering off issues, complete the following:
- Verify you are on current software, and if not, update to the latest software version. See: The specified item was not found.
- Complete a master reset. See: Reset: Nokia Lumia 925
- If the issue persists, see: Basic troubleshooting: Windows Phone