Originally Posted by jjaakk
Just bought a second hand SPG311 (Sony Tablet Z Wifi), and the bootloader is unlocked.
OTA upgrade to KitKat fails.
Can I relock the bootloader ? Will this allow OTA KitKat update to install ?
I believe you can simply relock your bootloader using Flashtool by following these steps:
1. Make sure you're using the latest version of flashtool
2. In flashtool click the button that says 'BLU'
3. When it asks you to, connect the tablet in flashmode (hold the volume down button while connecting it)
4. Click on 'Relock' on the prompt window that will open
5. Follow whatever instructions flashtool gives you and disconnect the device after its done
But please verify this by searching online before trying it out because I'm not an expert and I did this on a Xperia Z Ultra succesfully but not on the Tablet Z. I wouldn't want to be responsible for messing up your tablet!
Once you do relock the bootloader OTA updates will be allowed.