(Reading time: 1 - 2 minutes)

Sony Xperia Z1 hard reset

Reset your Sony Xperia Z1 C6902 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.

Sony Xperia Z1 hard reset

Sony Xperia Z1 hard reset using firmware update

You need an unlocked boot loader on your phone.
To check please access to the service menu by entering the following code in the dialer: *#*#7378423#*#*
Tap Service info > Configuration > Rooting Status. If Bootloader unlock allowed says Yes, then you can update your phone.
Note! The SD card of your device will be formatted and you will lose all content (for example photos, music, videos) when you unlock the boot loader.

If you want to upgrade your Xperia Z1 software / firmware you have to connect your turned off phone to a computer via USB cable, and press the Volume down key as the "flash key" until the flash tool recognize your phone. You also need Xperia Flash tool from sonymobile website. Sony mobile EMMA setup tool.
After you download the Sonymobile Xperia EMMA flashtool software, install it. Turn off your phone. Connect it via USB cable to your computer, while you press and hold the VOLUME DOWN key. In the flashtool the available software will be displayed under service window. Select it and press Apply service. The phone will be automatically flashed. After firmware update the phone will reboot. Be patient for the first time after upgrade. Note! After software update all data will be erased!
Sony Xperia Z1 Honami, Sony Xperia Z1 C6902 / L39h, Sony Xperia Z1 C6903, Sony Xperia Z1 C6906, Sony Xperia Z1 C6943

General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing 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.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.