I read that this procedure here helped others. You should give it a try.
Following the advice from ZnewmaN I am "copy-pasting" the instructions here. The article refers to Galaxy Nexus w/ Android 4.0.2 but you can follow similar steps for other scenarios too.
- Download the factory images to your PC.
- Unzip the file and its contents into your SDK/Tools folder (wherever your adb.exe and fastboot.exe files are). *Make sure they are not in their own folder, but have all been extracted to Tools.
- From within your Tools folder, open a command prompt (SHIFT + right click – “open command prompt here”):
- Type the following commands, allowing each to finish before moving onto the next:
adb reboot bootloader
fastboot flash bootloader bootloader-toro-primekk15.img
fastboot flash radio radio-toro-i515.ek02.img
fastboot flash radio-cdma radio-cdma-toro-i515.ek05.img
fastboot -w update image-mysid-icl53f.zip
fastboot oem lock
- Reboot your phone by highlighting “Start” and pressing the lock switch.
- It really is as simple as that. Your phone is now back to a 100% stock, unrooted and locked state.