[LG Optimus 4X HD] O4X75:
Hi

(Sorry for my little english, feel free to speak french if you can)

I have try to root my 4X HD for using a better recovery app (recover pictures deleted in sd card, now you know my skill). I have use this page: (as newbie i cant post outside links)

n fact, I never had an Android device where this was that easy to achive! Our friends at XDA-Developers offer a guide and the necessary tools in this thread. Having a "Microsoft free zone" and "only" running Linux machines (yeah, even the Android ones run a Linux kernel), I was able to follow up those steps with a little adaption here and there -- and so I will sum up the results for Windows and Linux users as well:

Preparation

First you need to download the required tools, all of them available at the linked XDA-Developers thread:

o4xr.zip is the rooting toolkit

IS11LG_SystemBackupTest.signed.apk to prepare your device

Windows users only: LGUnitedMobileDriver_Ver_3.7.2_LG-P880_LGO4XHD.zip -- the Windows drivers for the device

Having everything downloaded, some additional steps are necessary at your computer:

Windows users only: Unzip and install the drivers

Linux users: Make sure adb is able to detect the device (check with adb devices). If it's not, see at the end of this answer for some hints.

Everybody: Copy IS11LG_SystemBackupTest.signed.apk to your Optimus (e.g. after connecting it via USB in MTP mode, copy the file to the internal SDCard)

Everybody: Create a new directory, unzip o4xr.zip there, and change into this directory.

The rooting process

On your Optimus, go to Settings→Security and make sure "Unknown Sources" is TICKED (i.e. contains a checkmark)

Go to Settings→Developer Options and enable "USB Debugging"

Now install IS11LG_SystemBackupTest.signed.apk (e.g. use a file explorer to find and "launch" it)

Open the "SystemBackupTest" app you just installed. Nothing spectacular will happen, so don't be disappointed here.

Hold the power button and choose "Power off and restart".

When you can see the lock screen, you may notice that the phone is running very slowly, this is normal.

Once the device is fully started up again, connect it to your computer with an USB cable. Make sure the phone is in "Charging Only" mode.

On your PC, open a terminal (Linux) resp. command (cmd.exe, Windows) window and change into the directory you've extractedo4xr.zip` into.

(on Windows, you may need admin privileges: right click, run as administrator. On Linux it did fine for me without superuser/root permissions)

Now run the rooting script:

Windows users: type root followed by the enter key

Linux users: type ./root-linux.sh, also followed by the enter key

Any Mac users? Type ./root-mac.sh, also followed by the enter key. Don't worry, it won't root your Mac/Linux machine (Windows users: it is unlikely to root your box, either :)

DO NOT DISCONNECT YOUR PHONE WHILE THE SCRIPT RUNS! Wait while it does its job. During that process, the phone will reboot automatically a couple of times. The script will inform you about this in your command/terminal window. Once the command/shell prompt returns, the misdeed is accomplished :)

Now uninstall SystemBackupTest from your Optimus. Do not launch it again at this state, or you might have to start over from step 5 :)

On your phone, open up Google Play Store and search for "SuperSU". Update the app when prompted, then open it. Press OK to update the SU binary.

You now have root and can safely restore the "Unknown Sources" and "USB debugging" settings back to how you had them! Congratulations! Next steps are to install Titanium Backup, LBE Privacy Guard, and all the other things you might need and which require root!

At step 8. i got "command not found" in Terminal (Linux Mint), assuming script don't work i have reboot my device.

Since my phone boot but is very very slow and screen is friezed, even if i can unlock my SIM card by memory pattern (without sim card and always by memory i can see Settings of android but not down the list).

In recovery boot (Sound up + Power), my device show me a picture that would say "dont unplug charge and usb".

I guess my phone is not rooted, adb can list it but not fastbood. LG software (on windows 7) cant communicate with it because usb driver not work. I guess i've try and read more since 8 hours but my brain is off right now. Any help will be very welcome.

Cheers