Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.!
Sony Xperia U hard resetReset your Sony Xperia U Android phone
If your phone is responding to screen input, then open Settings from the Applications menu. Tap Backup & reset > Factory data reset, click Reset phone and then Erase everything to format your phone.
Your device freezes or has fatal errors
If your device freezes or hangs, you may need to close programs or reset the device to regain functionality. If your
device is frozen and unresponsive, press and hold the Power key for 10-15 seconds. The device will reboot automatically.
While using your device, be sure to back up important data. When disposing of your device, back up all data and then reset your device to prevent misuse of your personal information.