There are cases when you must relock your device bootloader in order to use your warranty. Otherwise, it can be rejected because of modifications made by user. In this tutorial we’ll show you how to bring back any Sony device bootloader to its factory state. Need to mention, that relock process is far more simple than unlocking bootloader.
- Download this Flashtool to PC.
- Launch it and click BLU button.
- Boot Sony into fastboot mode: turn off the device, hold Volume Up or Back button (depending on the model) and connect it to PC via USB cable. Release button after blue light appears on device.
- On the popup window choose Relock button.
- After relock process is complete, disconnect Sony from USB.
- Just to make sure that bootloader is locked, open dialer and type *#*#7378423#*#* then go to Service info/Configuration/Rooting Status. If you see „Bootloader unlock allowed: Yes“, this means that bootloader is successfully locked.