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[ Guides ] How To Unbrick /Updates firmware/ Flashing LG Android Devices

Unbrick LG Android SmartphoneGuides To Unbricking / Updates LG Android Devices


On this occasion we will learn how flashing / Software updates using KDZ_Updater_tools to fix System LG Android Smartphone problematic or broken, or we are familiar with the term Boot-Loop / Soft-brick “Only stay on LG Logo” and Hard -brick or total dead but the drivers still able to connect to a computer, and we are sure this is not a problem with the hardware. Usually caused by a virus attack, failed Rooting / installing fonts / Boot-animation, install ROM / Firmware wrong or crash in one application system or part of a system.


Tutorial with video : Watch here

Things that need to be prepared :

  • Windows PC
  • USB Cable
  • Download –> Download here
  • Download Verizon Drivers (Verizon Only) –> Download here
  • Download on PC –> Download here
  • Download –> Download here
  • Download Setup_LGFlashTool_1.8.1.1023.exe –> Download here
  • Download MegaLock.dll –> Download here
  • Check your LG Mobile Phone “model number & Suffix” on the battery and than download your Stock Rom .KDZ files –> Download here or search on google.

Notes : If your firmware is  .CAB, you need to convert .CAB  to .KDZ files

    • Extracts  and Open UpTestEX_mod2_marwin.exe
    • Wait for the program to open
    • Look for “Encrypt cab file to kdz file”LG .Cab to .KDZ File converter
    • Click the folder icon
    • Choose the location of the .cab you downloaded for your firmware
    • Encrypt cab -> kdz Program will freeze up. DO NOT EXIT until program shows the location of the new file!!! Otherwise it won’t finish converting.
    • Close program.

Or would it work if you took it a step further and converted the .KDZ file obtained using the above method into a .TOT file using the LGExtract tool from here and then flashing the .TOT file with LGFlashTool using the .DLL for the F3 from here? I know LGFlashTool works with .TOT files because I used it to downgrade my LG  so I could root after accepting an OTA update.

FIRST PROBLEM : If only bootloop or stuck on logo


Safe mode allows you to turn on the device with third-party apps disabled. Then you can easily remove all apps that may be causing a conflict or software problem.

To turn on safe mode and use it to fix app problems, follow these steps:

  1. From any screen, press and hold the Power key.
  2. Touch and hold Power off.
  3. Review the ‘Reboot to safe mode’ screen, and then tap OK.
    Note: The device will restart and ‘Safe mode’ appears in the lower-left corner.
  4. Uninstall any third-party apps that gave you problems.

To turn off safe mode, follow these steps:

  1. From any screen, press and hold the Power key.
  2. Tap Power off and restart.
  3. Tap OK.


SECOND PROBLEM : if devices experience hard bricked because error installing rom or firmware and you can not go into recovery mode.


Normal Flash : Flash ROM without losing any data. Only use this when you need to fix system error. Beware of boot loop when flashing ROM that differ from current ROM on your phone or MOD ROM.
CSE Flash : Choose this option when you need a fresh format. All data will be gone. It’s suitable for upgrading or downgrading ROM or simply use this when you need to back to Stock.

1. Flashing using LG KDZ Updater


  • Double click to Install LG Driver on your PC
  • Unpack / Extracts
  • Open folder /KDZ_Updater/KDZ_FW_UPD_EN/ double click to Install MSXML 4.0 SP3 Parser (msxml.msi) KDZ_Updater_Msxml
  • Run KDZ_FW_UPD.exeKDZ_Updater_Install
  • Set on Type=3GQCT and PhoneMode=DIAGKDZ_Updater_3GCT
  • Click folder logo on  KDZ file and select .KDZ Stock rom / Firmware your downloaded ( To example my firmware is V10k_00.kdz for LG P700)KDZ_Updater_FileSelected
  • Turn off your LG Smartphone
  • Connect your LG Smartphone to PC using USB Cable, the driver will auto installing on PCKDZ_Updater_Driver installed
  • Click LaunchSoftwareUpdates, KDZ_Updater_tools will auto unpacking firmware, your phone will open to Emergency mode automatically,  and than update process started. wait until process is complete.KDZ_Updater_SoftwareUpdaterKDZ_Updater_AutoUnpackKDZKDZ_Updater_Processinstalling
  • Done.


2. Flashing using LG FlashTool

  • Install LG Flash Tool and LG  Driver.
  • Turn off devices to enter download mode, make sure the battery state at power 60% ~ 70%.
  • Press the Volume Up (+) and Volume Down (-) and then connect your LG to Computer, so it will appear download mode on the LG screen.
  • Run LG Flash Tool now, at [Select KDZ file] –> select the .kdz firmware has been downloaded. Then you can choose Normal Flash for Flash ROM without losing any data. Only use this when you need to fix system error. Beware of boot loop when flashing rom that differ from current rom on your phone or Mod rom, or select CSE Flash if you want to downgrade or update aka LG factory reset and all data will be lost.
  • Select Start to begin the flashing process
  • No need to choose desired language, it automatically change to English as a default setting.
  • Wait until the update process is complete, make sure the cable not disconnected from PC when the update process, to avoid things that are not desirable. If  bootloop after the update, choose CSE Flash not to Normal Flash.
  • Done.

3. Flashing using LG FlashTools V1.8

Recover or return to the stock firmware AT & T, T-Mobile, Sprint, Verizon, & a The few International TOT`s that are available.

  • Download both stock firmware (Image & DLL File), you must be extracting TOT File if files compressed in .zip
  • Install Setup_LGFlashTool_1.8.1.1023.exe
  • Install LG driver
  • Copy & Paste MegaLock.dll File Into C:/LG/LGFlashTool/…HERE
  • Launch LG Flash Tool., Tick Select Manual Mode and Select Dll File &Tot File.
  • Select Manual Mode, than click the DLL Box and choose the DLL file from Above meant for your device
  • Now, Click the S/W box and select the firmware file with the .tot extension, Then Click OK when done.
  • Click the Yellow Arrow Button at the top left, The Firmware install will be triggered
  • Press Download Button, Now Port1 Shows (COM41)
  • Connect your LG to PC by Pressing Volume Up & Connect The USB Cable (you can see driver installation)
  • Go to Device Manager > Ports > Right Click On LGE Mobile USB Serial Port > Properties “Select Port Settings > Advanced”, and than Change COM Port Number COM25 to COM41 & click OK.
  • Start Flash now
  • Done. Enjoy it 🙂



Note :

  • If you cannot run LG FlashTool, please install Visual C++ Runtime Library –> Download HERE
  • 99% of the time FlashTool will FAIL after 85% anything after 85% is just your phone rebooting so your safe.
  • Manual Getting into Emergency Mode (Download Mode)
    From powered off,
    Hold volume up and down and plug in USB.
    and Select PhoneMode=EMERGENCY MODE on KDZ_Updater tool  (To get out of e-mode, hold power button for 10 seconds, or pull battery.) PLEASE DO NOT DO WHILE FLASHING.

Reggards, BoyCracked.

More guides for flash any android devices –> Read Here

Credits to : hyelton, quangnhut123 @XDA-Developer , habeebkambrath @Gsm-Forum and all android developer.



About BoyCracked

BoyCracked is a site that aims to facilitate the Android users around the world in terms of use or download files related to android system itself. >>>COMMENT RULES : You agree not to post any SPAM, no commercial advertising, no referal programs of any kind, abusive, obscene, vulgar, slanderous, hateful, threatening, sexually-oriented or any other material that may violate any applicable laws. Doing so may lead to you being immediately and permanently banned (and your service provider being informed. The IP address of all posts is recorded and part of it will be publised along with the post. You agree that boycracked have the right to remove, edit, move or close any topic at any time. Thanks for attention.


15 thoughts on “[ Guides ] How To Unbrick /Updates firmware/ Flashing LG Android Devices

  1. i have a lg g4 ls991 which is bootlooping not to mention no insurance how do i get this to stop


    Posted by Bigg Red | December 26, 2016, at 12:19 AM
  2. amigo ayuda el flash Tool tengo un pequeño problema pero ese pequeño problema me impide continuar. El archivo .dll como lo consigo no se si me salte algo. realmente no se que archivo .dll es ayuda por favor


    Posted by Erick Ramírez Veloz | November 21, 2016, at 12:46 PM
  3. Good day.
    i have done all that is needed to upgrade to MM still no success, after 2% it says retry, i tried to do the kdz updater it say file extract error. i have a lg g3 f400k 4.4.2 and dont know anymore what to do. can u help me?


    Posted by Mark Dela Cruz (@BryannMark) | November 9, 2016, at 5:16 PM
  4. Excuse me, i have followed all the step and execute
    method 1. Flashing using LG KDZ Updater.

    However, it always return an error message as below.
    Launching SW update
    Unpacking KDZ
    KDZ file extraced
    Extract file error

    i have also try to use method 2 Flashing using LG FlashTool

    but it stuck at 2 % and return failure.

    Anyone can help?

    My phone is F400L which cannot go into recovery mode. I can only going in to the download mode. The rom i use is F400L30c__00_1217.


    Posted by Keithforcook Wong | November 6, 2016, at 11:37 AM
  5. Thanks for this guide! i’m a totl n00b and I was able to recover my phone, I LOVE YOU!


    Posted by Somebody, someone (@aika_ve) | October 31, 2016, at 5:14 PM
  6. Hello. I have an LG G4 US99122a running on MM 6.0. I wanted to root the phone but I have researched that currently bootloader is locked on this model and cannot be rooted. Should I downgrade it to it’s stock rom running LP 5.1 and then rooth it from there? Any suggestion is much appreciated. Thanks.


    Posted by mark lester (@mark_spanky) | October 18, 2016, at 4:22 AM
  7. How to repair dead boot LS996 Qualcomm 9008 driver shown in device manager
    i download firmware and exracted after this guide me to repair hardbrick phone
    thankss for u r help full posts


    Posted by Niaz Hussain | October 8, 2016, at 6:09 AM
  8. I have tried this several times to unbrick my LG Optimus F3 LS720 without success. The KDZ_FW_UPD.exe software either freezes after reporting Unpacking KDZ (I wait several minutes after HD activity stops and Task Manager shows no CPU activity), or it finishes unpacking then complains that the phone is not found. I am using Emergency mode in the KDZ Updater and Download Mode on the phone since I can’t boot into System mode. Currently I can boot into Recovery Mode also (FreedomPop phone with TWRP, but my nandroid backups are corrupt and fail MD5 checks.


    Posted by Scotophor | September 25, 2016, at 1:15 PM
  9. Como puedo bajarle el modo download ami celular,tienen los archivos
    ? ya que se brickeo totalmente y no me deja entrar en ese modo


    Posted by facu | August 15, 2016, at 10:15 AM


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