Lg G6 downgrade

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granazias

Senior Member
Nov 22, 2014
106
35
LG V30
LG V50 ThinQ
Hey everyone, I'm having some trouble with my LG G6 and I don't know how to fix it. Ever since I updated the OS software to android Oreo 8.0, my fingerprint sensor stopped working. And this wasnt because the sensor was damaged, but because the whole fingerprint option was removed from the device. I was hoping to downgrade safely back to Android 7.0 without using ROMs if possible. If anyone has a solution to this problem contact me at my email with the steps and websites.

[email protected]

Also, I'm not a fully experienced android modder I've previously used ROMs and understand a little about GAPPs and how to install ROMs using TWRP on a Samsung device, however other than that I'm pretty oblivious to other information and tactics. Thank you in advance really, it would help alot.

If you want to try downgrade,you can find further instructions on post #6 and a few posts after that.
Also you must have LG drivers installed on your pc before starting all the process.
 

Arak0n

Senior Member
May 9, 2013
243
86
Can anyone tell me if I can downgrade using a full nandroid backup from my previous, working nougat/7.0 system, by just flashing back the backup?
I'd upgrade using a stock rom zip in TWRP, not using the kdz way.
 

evan8

New member
Nov 26, 2015
4
1
LG G6 H873 android 9 downgrade android 7

Required Files:
H87315d_00_OPEN_CA_OP_1226.kdz
LGUP_Ver_0_0_3_23.zip
LGUP_Common.rar
UPPERCUT_1.0.0.0.zip
LGUnitedMobileDriver_Ver_3.11.3
LG G6 H873 ANDROID 9


1. decompress LGUP_Ver_0_0_3_23.zip

2. install LGUP_Install_Ver_1_ just don't install LGUP_8994_DLL_Ver_0_0_3_23.msi

3. decompress UPPERCUT_1.0.0.0.zip

4. install LGUnitedMobileDriver_Ver_3.11.3.exe

5. decompress LGUP_Common.rar and copy it to the lgup directory
a. Download the Official KDZ firmware of LG G7
b. Uninstall LGUP if you have an old version, restart the PC, and install this new version of LGUP
c. Download this ZIP file LGUP_Common.rar
4. Open the ZIP and copy the DLL file ( named "LGUP_Common.dll" ) in this directory " C:\Program Files (x86)\LG Electronics\LGUP\model\common ". If there isn't the common folder, create it and copy the dll file inside.
d. Now the LGUP program works without any Error.

6 put in mobile mode download: press volume up and connect to pc with usb

7 Open LGUP, do not use UPPERCUT as it will fail and delete the LGUP_Common.rar that we copied in step 5 and you will have to do it again in step 5

The process starts normally and the device will be degraded to Android 7 without any problem
It does not allow me to include a link for being a new user but the process is simple I just made it
Screenshot-2020-02-12-15-19-32.png
 
Last edited:

banu89

Member
Jul 14, 2012
5
0
Hello guys, did anyone encounter this issue, i get the following error in lgup when trying to downgrade from android 9: Not support cross model download COMMON to H870, i used H87020a_00_OPEN_EU_OP_0423 , the phone is unlocked EU version.

UPDATE: I dont know why, but it worked after i updated to 30b ...
 

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geppy33

Member
Apr 8, 2020
15
0
LG G6 H873 android 9 downgrade android 7

Required Files:
H87315d_00_OPEN_CA_OP_1226.kdz
LGUP_Ver_0_0_3_23.zip
LGUP_Common.rar
UPPERCUT_1.0.0.0.zip
LGUnitedMobileDriver_Ver_3.11.3
LG G6 H873 ANDROID 9


1. decompress LGUP_Ver_0_0_3_23.zip

2. install LGUP_Install_Ver_1_ just don't install LGUP_8994_DLL_Ver_0_0_3_23.msi

3. decompress UPPERCUT_1.0.0.0.zip

4. install LGUnitedMobileDriver_Ver_3.11.3.exe

5. decompress LGUP_Common.rar and copy it to the lgup directory
a. Download the Official KDZ firmware of LG G7
b. Uninstall LGUP if you have an old version, restart the PC, and install this new version of LGUP
c. Download this ZIP file LGUP_Common.rar
4. Open the ZIP and copy the DLL file ( named "LGUP_Common.dll" ) in this directory " C:\Program Files (x86)\LG Electronics\LGUP\model\common ". If there isn't the common folder, create it and copy the dll file inside.
d. Now the LGUP program works without any Error.

6 put in mobile mode download: press volume up and connect to pc with usb

7 Open LGUP, do not use UPPERCUT as it will fail and delete the LGUP_Common.rar that we copied in step 5 and you will have to do it again in step 5

The process starts normally and the device will be degraded to Android 7 without any problem
It does not allow me to include a link for being a new user but the process is simple I just made it
Screenshot-2020-02-12-15-19-32.png

hello this guide is also good for h870?
thank you
 

SpeeDyLOCO

Member
Aug 14, 2013
10
1
I have already asked about it in another section but I would like to confirm here because it is the topic for this purpose:
I have a question, the H870 phone has genuine firmware without root. Recently, despite a long time of hesitating to update to 9, I made an update* to V30a-ORG-MCV: / the performance of the phone significantly decreased (antutu) from 162460 to 125317, updating to V30b-ORG-MV made the case even worse 115260, especially in terms of CPU performance. The question is, is it possible to downgrade to 8 without removing settings / data?

*I performed the update from the phone update notifications.

One more question, has anyone tried the "LG Bridge" error repair method? I mean, I just did it - once this option helped restore performance, for example in the G2 using LGMobile Support Tool.
Unfortunately, the effect of this operation did not bring the desired effect - the result of the antutu test was 124371** , which is even worse :D

And I mean whether it would be possible to force this program to be replaced with the correct ROM, eg 8. The program automatically connects to the server and downloads the latest rom and then "repairs" by first downloading the ROM to AppData \ Local \ LG Electronics \ LG Bridge \ SWUpgrade \ Image. I wonder if it would be possible to do such a repair by forcing the rom from 8 (H87020j_00).

**// After 2 days of use, the phone works a bit faster, but in the test result is still lower compared to version 8 (Oreo)> once it comes out 147829 and once 143825 with a fully charged phone.
 
Last edited:

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  • 5
    What are the steps to downgrading? I just bought my g6 and loved it. then i upgraded to oreo 8.0 cause the notifications were annoying me. but i HATE it and now im sad :( any help?
    You may want to look into anti-rollback numbers, because if you have one at a certain value, downgrading may brick your phone. I don't remember from the top of my head. Please be cautious and do this at your own risk.

    Look for "LGUP 1.14" and "LG Uppercut" on Google and download them. The first search results should be what you're looking for.

    Install LGUP first. Once that's done, put your phone in download mode by powering down and then turning it on while holding volume down and the lock button (the fingerprint sensor). Next, connect it to your computer.

    Open Uppercut (after extracting it) with administrator privileges. It will open LGUP. Have your KDZ ready somewhere easy to find, like your desktop.

    You should have four options that you can tick off, one of which is "REFURBISH". Select it.

    At the bottom, you will see a list. Select the first thing on the list and click on the three dots on the right. Select the KDZ. Finally, press start. DO NOT TOUCH YOUR PHONE WHILE IT IS DOWNGRADING! I AM NOT RESPONSIBLE FOR ANYTHING THAT HAPPENS!

    Once that's done, and ONLY when it says "finished" on LGUP's interface, your phone should boot at the set up screen.
    2
    Unlock BL and flash TWRP then Flash 7.0 based custom ROM

    What are you talking about...

    Lg up e uppercat e flash 7.0 kdz.

    Correct, just flashing 7.0 in Uppercut. But Factory Resetting might be needed, Oreo data might be incompatible with Nougat base.
    2
    Please can you tell me how to return Nougat from oreo. I have LG UP and I have official Nougat H870DSU10f_00_OPEN_HK_DS_OP_0803.kdz firmware downloaded. How to avoid brick and factory reset? Can I just refubrish from LG UP or I will have to do factory reset of the phone and "brick" at first?

    I did as described above. I was with Oreo 8.0. I downloaded LG UP with Uppercut, downloaded: H87011i_00_OPEN_EU_OP_0108.kdz, (Nougat factory image) then using Uppercut I selected "Upgrade" and pointed it to the downloaded KDZ. The flashing starting normally without any warnings, completed but then on first boot the phone kept crashing (I guess because Oreo data is not compatible with Nougat base as romcio47 says).

    At that point I thought I had a brick because the phone could not complete any action other than crash continuously. Then followed the instructions for booting into Bootloader: (volume down + Power for 10", keep both buttons pressed, when you see the LG logo immediately release and re-tap again the Power while volume is always pressed). There it only gives you one option: "Factory reset", selected YES, rebooted and then phone started normally into the Nougat setup.
    2
    From today i am a happy Nougat user again for my H870 EU model :)
    I've followed the exact instructions from @fegitoli,and i fortunatelly had the perfect result.

    Here i have to mention one detail that probably gave me the desired result..

    As it is mentioned in the instructions,i selected the "Refurbish" option,but when i pressed the start button,i got an error notification in LG UP display,saying that my kdz file can not be used for refurbish,so i cancelled the whole process without disconnecting my phone from the pc,but i closed the LG UP and opened Uppercat again.
    Probably the "refurbish" option is something like a hard(factory) reset mode for the existing ROM.

    Then i choose the "Upgrade" option and started the process again until i got the notification "completed" in LG UP interface.

    After the phone started rebooting,i disconnected it from pc,waiting to complete reboot.
    When completed reboot,i got an error saying "settings are not complete" and "safe mode start",but giving me the option "reset phone"..
    Then i pressed "reset phone" and a second reboot followed..after that,it opened the first set up screen and everything went fine.


    BE CAREFUL WHAT YOU DO AT YOUR OWN RISK..
    I AM NOT RESPONSIBLE FOR ANY DAMAGE ON YOUR PHONE!!

    P.S: Many thanks @fegitoli for his valuable help with his post!

    Sent from my LG G6 using XDA Labs
    2
    Be sure that if one on a million something was going wrong,i was not intented to blame you..;)
    What is everybody doing with his phone,is on his own responsibility.

    After a lot of reading here and in other forums,that a lot of people had problems with bricking their phones,i was prepared for the possibility to brick mine too,but i was decided to take the risk.
    Oreo,and especially the last June update,had disappointed me with the battery times,so i didn't have other option than to try the downgrade,and i am really happy that everything went fine.

    Maybe more people now can do the same and take the most from this wonderful G6.

    Regards!
    Very glad to hear that!
    Here's a little disclaimer I'd like to add. This should go without saying: YOU are responsible for what YOU do to YOUR phone. If you bricked it because you missed a step, it's not the instructor's fault. If everything is okay but the screen shuts off randomly, it's not the instructor's fault. Please mod responsibly and be prepared for failure, because things don't always work as they should.
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