If you have rooted your Sony Xperia Z Ultra smartphone and you are not happy with rooting and want to unroot your device, just follow this tutorial.
1.Just make sure your Sony Xperia Z Ultra smartphone was rooted. In case, if you are not sure about that, then download the Root Checker app from Google Play Store and check its status. If it is rooted, and you want to unroot then proceed the given below procedure.
2.Make sure your Sony Xperia Z Ultra smartphone battery level is above 75%. In case, if it is low, then charge the phone up to 100%. This step is highly recommended to avoid the power issues while unrooting your phone.
3.Please make a note that the given below procedure is working only on Windows-based computer and not on Linux, Mac, etc.
Procedure to Unroot Sony Xperia Z Ultra:
1.First download the Flashtool and appropriate FTF Firmware from here (depend on your country).
2.Once you have downloaded the files, just place them on your computer desktop.
3.After that double-click the Flashtool executable file and follow the installation instructions.
4.Then copy the FTF firmware file from your desktop over to the C:/Flashtool/firmware/directory on your computer.
5.After that turn OFF your phone and hold down the Volume Down button and plug your phone into the computer using USB cable.
6.Now, your phone should be in Flash mode.
7.Launch the flash tool program by double-clicking its icon available on your desktop.
8.In the program, just click the flash icon and it will ask you which mode you would like to use. Their select the “Flashmode”.
9.In next screen, tap the flash button the stock firmware starts to flash on your phone now.
10.Once the flashing process is finished, reboot your phone.
11.After that in your phone, go to Menu → Settings → Backup & Reset and tap on factory data reset.
That’s it! Now, your phone was unrooted, and stock firmware was restored. Enjoy the warranty of your phone.