How To Unbrick LG Optimus G – fix bootloop/security issues


How To Unbrick LG Optimus G – fix bootloop/security issues

The LG Optimus G is one powerful smartphone from LG’s latest creations, the phone is packed with a decent bunch of specs and features. Some people love to keep their smartphones always rooted to acquire full control over the device but rooting isn’t pretty easy, sometime it may damage your phone or you may get bootloops and security errors, some people face these errors during the installation of custom ROMs and tweaks, if you’re facing same issues, not to worry, simply say thanks to senior XDA developer member potatohead, he has found a way to unbrick the Optimus G.

This guide shows you how to unbrick Optimus G, use Windows PC and make sure USB phone drivers are installed on your PC, you can download drivers from here.

DISCLAIMER: Please proceed the below guide at your own risk, Android Egis will not be held responsible if your device lost data or gets damaged following this guide.


Step #1: Download the latest KDZ from here for your Optimus G with this app to your PC.

Step #2: Download the LG LDZ updater from here to your PC.

Step #3: Download manual ADB Wipe batch file from here.

Step #4: Turn off your Optimus G.

Step #5: Reboot phone into download mode, to do so reboot phone by holding down volume up and volume down buttons while plugging the phone to PC using a USB cable. PC may ask for drivers installed, let it install.

Step #6: Unzip the downloaded updater zip file.

Step #7: Go to updater folder and open up KDZ_FW_UPD.exe and use the following setting:
Type: 3GQCT
Phone Mode: CS_Emergency
KDZ file: navigate to the folder which you have saved the downloaded KDZ from the step 1.

Step #8: Open up the software update and wait for the installation. Your Optimus G will reboot automatically when IParam = 90 is displayed and proceed slower until you see IParam=1 again (which signals the end of flash, you can safely exit the program then and remove the cable from the phone). If phone boots up normally, don’t proceed next step, you’re done enjoy!

Step #9: If your life stuck at booting, you need to manually wipe the data partition. Turn off phone by holding down power buttons for a few seconds, then reboot it by holding the volume up and home button concurrently to enter in recovery mode, then press the power button. When you see LG logo two times and screen goes blank thereafter (backlight may still be on), leave all buttons.

Step #10: Once you’re in recovery mode, plug the phone to PC and wait for drivers installation if you’re plugging for the first time.

Step #11: Unzip the downloaded wipe batch file and run wipe.bat to execute the wipe command. Your phone will reboot after wipe and boot up normally.

That’s it, enjoy! Be sure to visit the original XDA thread to thanks/donate the original developer for this effort.

Related posts:

  1. How To Unlock AT&T Optimus G Bootloader – Guide
  2. How To Root LG Optimus G – Guide
  3. Update LG Optimus G to Android 4.2 Jelly Bean via CyanogenMod 10.1 [Canadian Only]
  4. Install ClockworkMod Touch Recovery on LG Optimus 4X HD
  5. Unbrick Your Verizon Galaxy S3 [How-To]

You can follow us on Twitter for random streams or free Newsletter Subscritions Join RSS or join our Facebook page to keep yourself updated on all the latest from Android, Google, TIps & Tricks, HTC, Android App Reviews, Android Mobiles, Honeycomb, Google Chrome, Chrome OS, Gadgets, Google News, webOS, android firmware and Chrome Extensions.
Tags:  ,  ,  ,  

Being a technology enthusiast, Abdur Rehman feels satisfaction when he is among latest gadgets and covering new waves of tech world.


  1. Ganix

    June 2nd, 2013

    Thanks for the info!!!!

  2. aDDaN

    June 25th, 2013

    IT DOESN’T work. KDZ FILE EXTRACT ERROR. What can i do with it? please answer

    • Abdur Rehman

      June 26th, 2013

      you should check the XDA thread to get it now… is given at the bottom of post….

  3. Evan Price

    July 17th, 2013

    cannot get the KDZ

  4. jeremy

    August 21st, 2013


    • Patrick

      September 26th, 2013

      I stuck on that too, how to get serial number when we can’t even boot? please advise

  5. Abner

    September 10th, 2013

    In the step 7 you say in the last part:
    KDZ file: navigate to the folder which you have saved the downloaded KDZ from the step 1.

    The file in the step 1 is exe program, doesn´t exist a KDZ file, so we can find it to go to another step.
    Can u please check the file? I will appreciate very much.

  6. satya

    September 10th, 2013

    same problem with my optimus black….should i try this method…waiting for your reply

  7. Abdullah

    September 12th, 2013

    will it solve the security error issue on my optimus f160k
    it was already on JB

  8. stimulation clitoris illustration

    October 18th, 2013

    Hi there, I read your blog like every week. Your writing
    style is awesome, keep doing what you’re doing!

  9. Alex

    November 28th, 2013

    I cant go into download mode what can i do ?

  10. Alex

    November 28th, 2013

    I Navigate into the folder where i download this but the folder its not showing me anything at all its empty even tought the document its there

  11. Percywal

    November 30th, 2013

    If u can’t get your serial number. here it is 355296054845917 (Lg optimus G) I hope this help you out :) enjoy!!!

  12. joe74

    January 3rd, 2014

    The hardest shit is to enter in download mode. It has to be at the same time, pressing up and down buttons and power and plug the USB, like playing violin and eating a sandwich.

  13. MOD

    February 4th, 2014


  14. axel

    March 29th, 2014

    y si no reconoce la pc el cel cuando lo conecto a lo computado?

  15. Radu

    June 26th, 2014

    Hello. The info and instructions posted were of big help to me because I was able to bring my Optimus G Intl back to life. Thanks Thanks Thanks !!!

  16. NaDream_Kim

    July 23rd, 2014

    Thank you for ur help ❤❤❤❤❤❤ this information can help my sis’s phone back to basic… I LOVE U

  17. Egill

    November 20th, 2014

    I did all the steps as described but I´m still stuck at the boot up flash

  18. ramki

    November 22nd, 2014

    my lg e975 softbricked and no display but when connected to pc it sounds like something connected and disconnected please help me………………

  19. outcast

    January 25th, 2015

    thanks for this post helped me fix the boot loop after downgrading my phone.

    LG LTE3 F260F


Leave a Comment

Name *

Mail (will not be published) *

Website (optional)

Your Comment *