I have installed the Ubuntu Touch Developer Preview on my Nexus 4. It is the problem when I want to get back to my android 4.2.2 but I wipe all my data first, from factory reset, cache partition and also the dalvik cache. Now, I cannot root my phone to android neither ubuntu because the pc cannot recognize my phone. Can you tell me what is my problem and how can I fix this? Thanks!
The first step is to reboot to the bootloader
First try to do this manually: make sure the phone is off (you can hold down the power + volume down and up buttions for 10 seconds if you can't turn it off though software)
hold down the power button and the volume down button at the same time until you reach the bootloader (you will see an android with a battery and the word start)
If that does not work turn off the phone again and this time hold power + volume down and up.
If again this does not work, use adb: for windows you may need some usb driver but since you installed ubuntu touch you should have them. You will not need any extra driver for ubuntu.
turn the phone on (it should not matter if the phone boot loops or anything, it just needs to be on). Go co cmd for windows or terminal for ubuntu. If you do not already have adb, download it form here windows: http://dl.google.com/android/installer_r22.0.1-windows.exe linux: http://dl.google.com/android/android-sdk_r22.0.1-linux.tgz
type cd then drag the "platform-tools" directory to your respective command line and hit enter.
Then, for windows type:
Now that you are in the bootloader plug in your phone.
download the factory images here: https://developers.google.com/android/nexus/images
extract the folder.
now in your command prompt type cd then drag in the extracted folder and hit enter.
for windows type:
What OS are you using? if it is ubuntu Have you installed ubuntu SDK?
Anyway the instruction to restore to Android can be found here On Restoring Android Section For more help you can also contact ubuntu-touch channel on IRC http:// webchat.freenode.net/?channels=ubuntu-touch