Manually Install/Upgrade LG Optimus 4X HD P880 to V20A Official Android 4.1.2 Jelly Bean Firmware

Okay just a heads-up for those looking for the LG Optimus 4X HD P880 official Android 4.1.2 Jelly Bean update. The Jelly Bean update build version V20A is already rolling out, all you need is PC suite or mobile tool to get this update into your devices.  This build version leaked a while ago and I just want post this up to let everyone looking for the official V20A firmware builds and manually install it.

Update LG Optimus G 4.1.2 V20A

 

In Addition,you can now unlock the bootloader and easily install root on this v20a 4.1.2 JB version, then install a CWM recovery as you wish.

LG optimus 4x hd 4.1.2 v20a

How to manually install V20a official 4.1.2 Jelly Bean on LG Optimus 4X HD P880

Disclaimer: Use of this guide is solely at your own risk. We shall not be held responsible if anything happens to your devices by using this guide. This procedure is for advance users only.

  • Back up all important files stored from your device, although this process will not wipe data but if you need to factory reset, you should do some back-up first.
  • Install necessary drivers from here.
  • Grab the official Android 4.1.2 Jelly Bean Firmware*.kdz file from XDA-Developers.

Turn off your phone,
Press and hold Volume down button and connect the phone to the PC while still holding Volume down button
Once the phone connected, you should see a S/W screen mode, if not re-installthe necessary drivers
Now re-insert the battery.
Go to device manager and select “disable LGE Modem”.
Run the KDZ_FW_UPD.exe and Windows Enabler.exe as an Administrator.
Windows Enabler.exe should appear in taskbar somewhere near clock, click once till you can see ‘On’
In KDZ_FW_UPD.exe select 3GQTC as type and DIAG as PhoneMode
Browse and select your *.kdz file and press ‘Launch software update’
Do not click program window even if is ‘Not responding’! Wait till flashing ends
Phone will reboot and you can remove USB cable

How to  Root, Unlocked Booloader, CWM Recovery

Now, you may proceed to root it here, to unlockbootloader and installing CWM recovery here.

That’s all!  Thank’s to fellow XDA folks for keeping this up!