Develop Bugs

[Q] Downgrade from android L on LG G3

Hey guys massive noob here, wondering if it is possible to downgrade from android l to kitkat or to root android L on the G3. I foolishly updated and my root is gone, stump is not working (obviously not made for L yet) and I can't find any help elsewhere.
I need to root my phone and I don't care whether the the best way is to downgrade or to root if it is available for the new os. I will lose my data other than what is backed up via dropbox etc but it's not a big deal for me.
Help much appreciated thanks

Yes it is possible just downgrade to Kitkat using the lg flash tool then root using Purpledrake
You can get the KDZ file required from this link : http://forum.xda-developers.com/showthread.php?t=2791761 (make sure you select the correct file)
LG Flash tool: http://forum.xda-developers.com/showthread.php?t=2785089
Root: http://forum.xda-developers.com/lg-g3/development/root-root-lg-g3-easily-purpledrake-lite-t2821000

Yup, what he said it's fairly easy. Give it try, let us know if you need help.

cyaiphone said:
Yup, what he said it's fairly easy. Give it try, let us know if you need help.
Click to expand...
Click to collapse
Ok thanks guys I'll give it a go thanks for the really quick replies

ineedahand said:
Ok thanks guys I'll give it a go thanks for the really quick replies
Click to expand...
Click to collapse
I've fallen at the first hurdle, which firmware do I need?
I have a UK vodafone LG G3, 16GB, LG-D855, and I want the last version of kit kat available. I'm more than a noob.. .
Also why do you choose Purpledrake over stump, is there any difference?
Thank you so much

This firmware you want is A6VF, it is near the bottom of the list.
The reason I use purpledrake over stump is because some times it won't root and says "...Not supported" but feel free to try stump if you want and if it doesn't work just use purpledrake.

Hi. I got trapped with unrooting and updating to lollipop lg g3 D85520e-EUR-XX and wanted to return to kit kat 4.4.2. It's the 32 Gb model. Can you help with the KDZ i must download (I can't understand the four first characters of the list!). Thanks!

What network are you currently using? or is it an unlocked phone. A country name would also be helpful as that's how the files are organized.

KickingWriter said:
This firmware you want is A6VF, it is near the bottom of the list.
The reason I use purpledrake over stump is because some times it won't root and says "...Not supported" but feel free to try stump if you want and if it doesn't work just use purpledrake.
Click to expand...
Click to collapse
Thanks for the help man, I've tried getting into download mode as required but I am stuck at 0% on the firmware update, any suggestions
Thanks

ineedahand said:
Thanks for the help man, I've tried getting into download mode as required but I am stuck at 0% on the firmware update, any suggestions
Thanks
Click to expand...
Click to collapse
The Percentage will stay at 0% until you start the LG Flash Tool , The tutorial tells you what to do

KickingWriter said:
The Percentage will stay at 0% until you start the LG Flash Tool , The tutorial tells you what to do
Click to expand...
Click to collapse
You're a a lifesaver man thank you so much it worked!

Is everything working okay? Has it booted?

KickingWriter said:
What network are you currently using? or is it an unlocked phone. A country name would also be helpful as that's how the files are organized.
Click to expand...
Click to collapse
It's unlocked. It's in Spain. Lg g3 D85520e. 32 Gb model. It came with kit kat 4.4.2 and i aplied PurpleDrake succesfully. Then I unrooted to upgrade to Lollipop 5. Ver. 20e. And now, I can't root anymore. So I would like to downgrade to Kit Kat 4.4.2 to be able to root again with PurpleDrake to recover my root privileges, especially to manage apps and their writing to the external sd card.
Thanks very much for your help!

To get the exact suffix required use this website
http://csmg.lgmobile.com:9002/csmg/b2c/client/auth_model_check2.jsp?esn=IMEI
Replace IMEI with your imei then press enter. Then post your suffix

It looks like if it were the same KDZ already installed... : FW9BRPVE022NAX045560S86/D85520E_00.kdz ??? What I need is the Kit Kat version 4.4.2 10x(a,b,c,...) to downgrade from this one (20e) and be able to root again the phone. I probably have explained myself wrong. Any idea?
And thanks for your efforts, by the way!
OK
355673062851055
LGD855
AITATN
408KPWQ285105
D85520E_00
xttp://csmgdl.lgmobile.com/dn/downloader.dev?fileKey=FW9BRPVE022NAX045560S86/D85520E_00.kdz
N
N
2

This is the Kitkat KDZ file you need AITA

Don’t forget you have to wipe all even bteetr hared reset with recovry after downgreat back to 4.4.2...

u1988 said:
Don’t forget you have to wipe all even bteetr hared reset with recovry after downgreat back to 4.4.2...
Click to expand...
Click to collapse
If he does a CSE flash he won't need to? Just making sure.

That's it! I'm going to download! Thanks very much. Everything is possible with people like you!

I'm glad we could help Keep me updated on your progress in case you have any problems.

Please need help! Rooting

Can i root my lg g4 with this version? And how?

Sure. Perfectly. At least two different ways. If you do not need and care about device encryption just search for the low effort root in this LG G4 Forum original Android Development. Search for a flashable 10C rom.
If you need device encryption, go to LG unlock your bootloader officialy, flash TWRP and flash su.
Thread for this is right here in General G4. Called complete Guide to unlock & Flash H815 or similar.
Sent from outer space using telepathy

fpsq said:
Sure. Perfectly. At least two different ways. If you do not need and care about device encryption just search for the low effort root in this LG G4 Forum original Android Development. Search for a flashable 10C rom.
If you need device encryption, go to LG unlock your bootloader officialy, flash TWRP and flash su.
Thread for this is right here in General G4. Called complete Guide to unlock & Flash H815 or similar.
Sent from outer space using telepathy
Click to expand...
Click to collapse
If my phone stuck at lg logo what can i do then?

a bit more detail would be nice. What did you try to do?

fpsq said:
a bit more detail would be nice. What did you try to do?
Click to expand...
Click to collapse
Root

Please try KingRoot. Apk

ketan22 said:
Please try KingRoot. Apk
Click to expand...
Click to collapse
Kingroot doesn't work. Lol

Root Help
Given an Ig g4 h815 software version v10d to the system.rooted.h815v10c.img this file rooting this solution is possible http://forum.xda-developers.com/g4/...-tmo-vzw-intl-variants-soon-root-lg-t3164765?

xdaorxan said:
If my phone stuck at lg logo what can i do then?
Click to expand...
Click to collapse
Hi, unfortunately this happened to me (more than once) when I tried rooting the first time. You'll need to download the stock image files and the LG Flash Tool to start over from scratch. I'd link you but I don't have enough posts yet to be able to.
The trick is to make sure the rooted image file is over 4 gigs when extracted, I ran into issues multiple times where the download got corrupted along the way and ended up being a few hundred meg. Keep trying and once you get the right files the Low Effort Root is amazing.
Good luck and if you need any more help please let me know!

H815 TWN, differences from EU?

I am certain my G4 is TWN, from the box and the software version. But what are the actual differences to the European H815? Specifically, can I flash European KDZs or use the EU command for flashing a rooted /system image?
Code:
dd if=/data/media/0/system.rooted.H81510c-EU.img bs=8192 seek=55296 count=529920 of=/dev/block/mmcblk0
Thanks

I have a the TWN version too damn it. - that's what happens when you buy from a global vendor over the internet .
Good news is that you can flash the EU rooted system image. I did and it worked fine.
Bad news is that you can't unlock the boot loader (yet), which means no TWRP or custom roms and flashing a stock Marshmallow leaves you without root and no way to downgrade.
Cheers
BTW I don't know of any differences between the EU and TWN devices other than the version coding - to me it just seems to be a way for LG to control their different markets.

Thank you for this. I do not want to unlock it just yet, since I bought it from a local vendor and I have a 2 year warranty with them. I see there is already a rooted image for v10d TWN, so I will flash that soon (are you sure the parameters for the dd command are the same?).
Sidenote, it would be nice if we could compile our own KDZs and make rooted ones.

metalboy94 said:
Thank you for this. I do not want to unlock it just yet, since I bought it from a local vendor and I have a 2 year warranty with them. I see there is already a rooted image for v10d TWN, so I will flash that soon (are you sure the parameters for the dd command are the same?).
Sidenote, it would be nice if we could compile our own KDZs and make rooted ones.
Click to expand...
Click to collapse
I can't really comment on the all the parameters in that command string except to say that it's one I used and it worked well. Whether those numbers would need to be modified for the 10D image or not I can't say - I would suggest you ask the author of that original rooting thread.
BTW you can't unlock the bootloader on the TWN version just now in any case. I tried the official method over the weekend and was told the TWN version was not supported. There's unofficial unlock method available for any G4 variant yet either but people are working on it.

wadken1 said:
I can't really comment on the all the parameters in that command string except to say that it's one I used and it worked well. Whether those numbers would need to be modified for the 10D image or not I can't say - I would suggest you ask the author of that original rooting thread.
BTW you can't unlock the bootloader on the TWN version just now in any case. I tried the official method over the weekend and was told the TWN version was not supported. There's unofficial unlock method available for any G4 variant yet either but people are working on it.
Click to expand...
Click to collapse
Probably the parameters aren't different between firmware images, because they depend on the partition table of the device.
Now waiting for a version of Xposed that is confirmed not to drain battery. Thanks again!

I'm running xposed now with about 10 modules. I don't see any great battery drain.

wadken1 said:
I have a the TWN version too damn it. - that's what happens when you buy from a global vendor over the internet .
Good news is that you can flash the EU rooted system image. I did and it worked fine.
Bad news is that you can't unlock the boot loader (yet), which means no TWRP or custom roms and flashing a stock Marshmallow leaves you without root and no way to downgrade.
Cheers
BTW I don't know of any differences between the EU and TWN devices other than the version coding - to me it just seems to be a way for LG to control their different markets.
Click to expand...
Click to collapse
Hang on, I can flash MM into my TWN? I missed that, how does that work? Is there a thread?

wadken1 said:
I have a the TWN version too damn it. - that's what happens when you buy from a global vendor over the internet .
Good news is that you can flash the EU rooted system image. I did and it worked fine.
Bad news is that you can't unlock the boot loader (yet), which means no TWRP or custom roms and flashing a stock Marshmallow leaves you without root and no way to downgrade.
Cheers
BTW I don't know of any differences between the EU and TWN devices other than the version coding - to me it just seems to be a way for LG to control their different markets.
Click to expand...
Click to collapse
I did the same thing, buying online and getting stuck with TWN. I came from a GS6 and was thinking "I'll wack an AOSP ROM on the G4 and I'll have the perfect phone". Now I'll probably never buy another LG even though I actually like the G4 but when we pay close to $1k for a phone we should be able to do what we like with it!

There is a thread for stock marshmallow which you can install with flash fire but there's no root available with that option just now.

wadken1 said:
There is a thread for stock marshmallow which you can install with flash fire but there's no root available with that option just now.
Click to expand...
Click to collapse
I've tried to find the correct thread but could you point me in the right direction?
Thanks

gz5ztg said:
I've tried to find the correct thread but could you point me in the right direction?
Thanks
Click to expand...
Click to collapse
Sorry. Missed this while I was away.
The thread I'm talking about is http://forum.xda-developers.com/g4/development/stock-h815-20a-stock-rom-t3233049
BUT be warned you will lose root !!. So far as I know just now there is no way to get root on stock MM without an unlocked bootloader. This may have changed inthe last couple of days - you'll need to read around the forum.
ALSO there is no sure way back to L is you decide you can't live without root (I certainly couldn't so I'm waiting for further developments). I think I read that someone here more-or-less accidentally managed to recover back to L but I didn't really have time to take in all the details so futher reading needed if you want to take the risk.

wadken1 said:
Sorry. Missed this while I was away.
The thread I'm talking about is http://forum.xda-developers.com/g4/development/stock-h815-20a-stock-rom-t3233049
BUT be warned you will lose root !!. So far as I know just now there is no way to get root on stock MM without an unlocked bootloader. This may have changed inthe last couple of days - you'll need to read around the forum.
ALSO there is no sure way back to L is you decide you can't live without root (I certainly couldn't so I'm waiting for further developments). I think I read that someone here more-or-less accidentally managed to recover back to L but I didn't really have time to take in all the details so futher reading needed if you want to take the risk.
Click to expand...
Click to collapse
Okay thanks, maybe I will wait. This is going to sound like a completely noob type question but what is it that you are doing that you couldn't live without that requires root?

gz5ztg said:
Okay thanks, maybe I will wait. This is going to sound like a completely noob type question but what is it that you are doing that you couldn't live without that requires root?
Click to expand...
Click to collapse
Here's a few of the things I use which need root:
TI Backup
LMT Launcher
Bubble UpnP
FX Explorer (with root)
Gravity Box (xposed) to give expanded desktop
Llama + Secure settings (allows for automated control of airplane mode, gps and others which have been denied by google for default seetings)
Buidprop editor - allows altering a number of settings but especially DPI
Greenify advanced functions
Amplify
Better Battery Stats
Flashfire
Busybox
Viper4Android
SE Linux Mode Changer (needed to allow Viper to work)

[Thread Moved to General] Unlocked Bootloader on H818!

Thread moved to General - https://forum.xda-developers.com/g4/general/unlock-bootloader-h818-t3564238

Hello Thanks for your work.. Will this work for LG G4 H818N?

rshanubh said:
Hello Thanks for your work.. Will this work for LG G4 H818N?
Click to expand...
Click to collapse
It might. Read the guide again.

Hello could it work on H815 ?

onotor said:
Hello could it work on H815 ?
Click to expand...
Click to collapse
H818P for now. If your phone is similar to H818P and you could successfully flash H818P firmware in your phone. You can use the patched aboot.

rshanubh said:
Hello Thanks for your work.. Will this work for LG G4 H818N?
Click to expand...
Click to collapse
If your phone is similar to H818P and you could successfully flash H818P firmware in your phone. You can use the patched aboot.

pvineeth97 said:
If your phone is similar to H818P and you could successfully flash H818P firmware in your phone. You can use the patched aboot.
Click to expand...
Click to collapse
Yes I can do that.. Let me try and update you. Thanks again

i will test it tonight but the Q here can i relock the bootloader or what ???
oh and thanks man for your hard work i thought that i will wait for ever for the unlock.

Can someone give an example how to find Out what to Type for "<your aboot partition>" ?

pvineeth97 said:
Hi guys!
Disclaimer:
No more secure boot error!
I thank my friend @cerg2010cerg2010 for helping me out in patching the aboot.
-> Requirements:
LG G4 LGH818P
Rooted Phone
-> Steps:
(1) Downgrade to Lollipop version of the Android. Download here.
(2) Root your device.
(3) Download the patched aboot file. Click Here.
(4) Connect your phone to the computer. In command prompt, type "adb shell".
(5) Transfer the aboot file into /sdcard/ folder.
(6) Type "su" to enter the root shell. Then type "dd if=/sdcard/aboot_237568.bin of=/dev/block/<your aboot partition>".
(7) Restart your phone by typing "reboot".
You have unlocked your bootloader!
Refer Notes for more information.
-> Notes:
1) The aboot_237568.bin is the patched version of aboot partition of your device. Secure boot validation has been patched such that secure boot is always valid, so you can flash your own TWRP and Custom ROM.
2) Don't upgrade to any updated version of Android if you get any through OTA update. It might brick your device.
Click to expand...
Click to collapse
Sounds amazing. Please provide the details about the patch meaning what have you done exactly to get that patched aboot?
Could you please download my latest TWRP beta(!) and provide me the recovery log? Or someone else of course
My latest beta is a unified variant and so should work for h818 as well but maybe I need some small adjustments..
.
Sent from my LG-H815 using XDA Labs

Well I have to say I'm impressed. Share your method with us and spread unlock for all variants! G4 might finally reborn!
Sent from my LG G4 using XDA Labs

Engelm said:
Can someone give an example how to find Out what to Type for "<your aboot partition>" ?
Click to expand...
Click to collapse
adb shell
ls -al /dev/block/platform/<change your folder name>/by-name

ShadowMax Max said:
i will test it tonight but the Q here can i relock the bootloader or what ???
oh and thanks man for your hard work i thought that i will wait for ever for the unlock.
Click to expand...
Click to collapse
When you flash the patched aboot, the bootloader is unlocked. You don't need to do anything else.

steadfasterX said:
Sounds amazing. Please provide the details about the patch meaning what have you done exactly to get that patched aboot?
Could you please download my latest TWRP beta(!) and provide me the recovery log? Or someone else of course
My latest beta is a unified variant and so should work for h818 as well but maybe I need some small adjustments..
.
Sent from my LG-H815 using XDA Labs
Click to expand...
Click to collapse
Patched the secure boot validation function. The patched aboot has the secure boot set to always valid condition no matter what image you flash.

And after flashing KDZ the bootloader will still be unlocked ?

punkore said:
And after flashing KDZ the bootloader will still be unlocked ?
Click to expand...
Click to collapse
Proably not. Aboot is part of kdz flashing.

This is fantastic news! H812 user from Canada here hoping you can make this patch process work for our aboot too!

As in case of g flex 2..
Everyone be warned..
The aboot on lg k10 is not signed
But in lg g4 there is a hash verification to aboot.
It may result in a hard brick.. so be warned

first of all , thats great news. this is the same method we use in h815 with the unlock.bin from lg but instead of pushing the file directly, we flash it in bootloader. clever and nicely done.
since its public you should share it the right way not like this. i mean this is not a development project, this is about unlocking and flashing twrp. it should be a DEVDB thread in general under utilities section so that everyone can find it. Also the title should be: "Unlock Bootloader H818".
As it is, in a week or two its gonna fall at a second page and in search results also almost noone is gonna find it cause of the title.
in the op tell them about mmcblk0pX. They are not all expert , they don't know mmcblk0pX in g4 is like our sdX in linux.
Tell them the ls command to find which mmcblk0pX is the right one or how to find it with a root explorer. As it is, its just gonna give them an error and gonna ask you everyday about that.
We need h818 users too. To be able to start developing for more variants its important. Cooperate with steadfasterX to correct bugs in twrp (if there are any).
This would be the 1st step to start flashing together with us , custom roms.
Finally , Welcome H818 users

Oi funciona no h815p Brasil com o Android 6.0?

LG G4 (H815) Android Upgrade

Hello guys,
I am using an unlocked H815 in India (bought from ebay) which is running software version Android Lollipop. The software update check always shows "You have latest updates installed".
Is there any way I can upgrade the OS without bricking the phone or causing simlock.
Sorry if this is an already posted query.
Please guide me.

you need to study it ....

rotoko said:
you need to study it ....
Click to expand...
Click to collapse
Study what?

[email protected] said:
Hello guys,
I am using an unlocked H815 in India (bought from ebay) which is running software version Android Lollipop. The software update check always shows "You have latest updates installed".
Is there any way I can upgrade the OS without bricking the phone or causing simlock.
Sorry if this is an already posted query.
Please guide me.
Click to expand...
Click to collapse
Can i get some help.
Still didnt find a solution. Stuck on Lollipop while the G4 world moved through Marshmallow to Nougat.

[email protected] said:
Hello guys,
I am using an unlocked H815 in India (bought from ebay) which is running software version Android Lollipop. The software update check always shows "You have latest updates installed".
Is there any way I can upgrade the OS without bricking the phone or causing simlock.
Sorry if this is an already posted query.
Please guide me.
Click to expand...
Click to collapse
have you tried LGUP to flash a rom to marshmallow?

okadamikki said:
have you tried LGUP to flash a rom to marshmallow?
Click to expand...
Click to collapse
Hi,
Sorry for very late reply. Never thought someone would care to help after such a long time.
I never tried LGUP because I cant find the right ROM for my device. Hardware info page shows H815 while on adb it shows up as LGF500L.....(last time I checked F500L is korean variant).
Also the device does not have recovery mode. When trying to boot into recovery a red exclamation comes up with "No command" written.

[email protected] said:
Hi,
Sorry for very late reply. Never thought someone would care to help after such a long time.
I never tried LGUP because I cant find the right ROM for my device. Hardware info page shows H815 while on adb it shows up as LGF500L.....(last time I checked F500L is korean variant).
Also the device does not have recovery mode. When trying to boot into recovery a red exclamation comes up with "No command" written.
Click to expand...
Click to collapse
Sounds like it might be a 'frankenphone' - the only way to fully ascertain what the phone model actually is, is to open it up and see what is printed on the motherboard. Refer to this link on how to tear it down: https://www.ifixit.com/Teardown/LG+G4+Teardown/42705
You can also then use SALT to ascertain what the GPT compatability is - that will tell you what roms are safe to flash in order to upgrade.

sdembiske said:
Sounds like it might be a 'frankenphone' - the only way to fully ascertain what the phone model actually is, is to open it up and see what is printed on the motherboard. Refer to this link on how to tear it down: https://www.ifixit.com/Teardown/LG+G4+Teardown/42705
You can also then use SALT to ascertain what the GPT compatability is - that will tell you what roms are safe to flash in order to upgrade.
Click to expand...
Click to collapse
Can I manually install recovery(twrp or something) and change to a custom rom from there?
Will that be possible.

[email protected] said:
Can I manually install recovery(twrp or something) and change to a custom rom from there?
Will that be possible.
Click to expand...
Click to collapse
tutorial: https://forum.xda-developers.com/g4/general/howto-complete-guide-to-unlock-twrp-t3370003
Can you just install cpuz and see is it fake?

NikBos said:
tutorial: https://forum.xda-developers.com/g4/general/howto-complete-guide-to-unlock-twrp-t3370003
Can you just install cpuz and see is it fake?
Click to expand...
Click to collapse
As per CPU-Z ( I have attached screenshot of the same)
Model : LG H815
Hardware : p1
Board : MSM8992

[email protected] said:
As per CPU-Z ( I have attached screenshot of the same)
Model : LG H815
Hardware : p1
Board : MSM8992
Click to expand...
Click to collapse
CPU-Z will not be reliable in the information it provides you as it only provides the information that has been installed on it. As I stated, the only way to truly ascertain is to strip it down and see what is printed on the motherboard - it is not difficult and there are no shortcuts to be 100% sure - if you don't do it the way I suggested, you run the risk of hard-bricking your phone when you flash something not meant for your phone. If you doubt me, check with steadfasterX, recognized developer who know this stuff inside-out ...
---------- Post added at 03:30 PM ---------- Previous post was at 03:27 PM ----------
[email protected] said:
Can I manually install recovery(twrp or something) and change to a custom rom from there?
Will that be possible.
Click to expand...
Click to collapse
If your bootloader is actually unlocked, you should be able to - you should use the latest 'preview' version for the rom version you are planning to flash. Refer to this link: https://forum.xda-developers.com/g4/development/recovery-twrp-3-touch-recovery-t3442424
Note: The Thanks button at the bottom right of this post, is there for a reason. It is an XDA courtesy to use it when members are answering your questions or trying to help solve your issues.

sdembiske said:
CPU-Z will not be reliable in the information it provides you as it only provides the information that has been installed on it. As I stated, the only way to truly ascertain is to strip it down and see what is printed on the motherboard - it is not difficult and there are no shortcuts to be 100% sure - if you don't do it the way I suggested, you run the risk of hard-bricking your phone when you flash something not meant for your phone. If you doubt me, check with steadfasterX, recognized developer who know this stuff inside-out ...
---------- Post added at 03:30 PM ---------- Previous post was at 03:27 PM ----------
If your bootloader is actually unlocked, you should be able to - you should use the latest 'preview' version for the rom version you are planning to flash. Refer to this link: https://forum.xda-developers.com/g4/development/recovery-twrp-3-touch-recovery-t3442424
Note: The Thanks button at the bottom right of this post, is there for a reason. It is an XDA courtesy to use it when members are answering your questions or trying to help solve your issues.
Click to expand...
Click to collapse
Ok. Will try if flashing twrp is possible.
I will post an update after that.

[email protected] said:
Ok. Will try if flashing twrp is possible.
I will post an update after that.
Click to expand...
Click to collapse
Flashing through fastboot is not possible.....phone wont get detected in fastboot mode.

[email protected] said:
Flashing through fastboot is not possible.....phone wont get detected in fastboot mode.
Click to expand...
Click to collapse
Can somebody give me a link for the right kdz for my phone.
Current installed software version : H81510h (So I hope flashing it might revive the phone).
Note : Quick reminder, this phone is unlocked and using in India.

[email protected] said:
Can somebody give me a link for the right kdz for my phone.
Current installed software version : H81510h (So I hope flashing it might revive the phone).
Note : Quick reminder, this phone is unlocked and using in India.
Click to expand...
Click to collapse
When you say 'unlocked' you are referring to carrier/sim unlocked I presume. If you were actually bootloader unlocked, you should be be able to flash TWRP in fastboot mode.
Look, I'll say it again, strip your phone down and find out exactly what is stamped on the motherboard. The last thing you want to do is try and flash a rom from a different model than you actually have.
Then look for a MM 1220x up to 1220z rom for the phone model you actually have and upgrade it with LGUP-NEW. Then proceed to unlock your bootloader. If it is actually an H815 European version you should be able to unlock it officially on LG's site. If it another H815 version etc., you will have to unlock it unofficially with steadfasterX's UsU method BUT you must be on MM to avoid issues when installing any custom roms from then on.
Don't take any shortcuts.

sdembiske said:
When you say 'unlocked' you are referring to carrier/sim unlocked I presume. If you were actually bootloader unlocked, you should be be able to flash TWRP in fastboot mode.
Look, I'll say it again, strip your phone down and find out exactly what is stamped on the motherboard. The last thing you want to do is try and flash a rom from a different model than you actually have.
Then look for a MM 1220x up to 1220z rom for the phone model you actually have and upgrade it with LGUP-NEW. Then proceed to unlock your bootloader. If it is actually an H815 European version you should be able to unlock it officially on LG's site. If it another H815 version etc., you will have to unlock it unofficially with steadfasterX's UsU method BUT you must be on MM to avoid issues when installing any custom roms from then on.
Don't take any shortcuts.
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Opened up the phone and found that it is H815 after all.
So can somebody now guide me to which rom/kdz I should use.
[Currently on Lollipop..SW Version : H815 10h]

[email protected] said:
Opened up the phone and found that it is H815 after all.
So can somebody now guide me to which rom/kdz I should use.
[Currently on Lollipop..SW Version : H815 10h]
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Click to collapse
Here's a good site to download firmwares from: https://lg-firmwares.com/lg-h815-firmwares/firmwares/
Your looking for an H81520 with the latest alphabetical letter ... You'll have to decide on the one you want to try installing.

sdembiske said:
Here's a good site to download firmwares from: https://lg-firmwares.com/lg-h815-firmwares/firmwares/
Your looking for an H81520 with the latest alphabetical letter ... You'll have to decide on the one you want to try installing.
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Click to collapse
Thanks for the link.
So I may download kdz with H815 20 with latest alphabet (and no need to look particularly for H815 20h right).

[email protected] said:
Thanks for the link.
So I may download kdz with H815 20 with latest alphabet (and no need to look particularly for H815 20h right).
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Correct. You will not find a 20h as the lower letters are used for previous android versions, higher letters for newer versions.
You are forgetting the 'Thanks' button at the bottom right of the posts - it's a good habit to get into ...

sdembiske said:
Correct. You will not find a 20h as the lower letters are used for previous android versions, higher letters for newer versions.
You are forgetting the 'Thanks' button at the bottom right of the posts - it's a good habit to get into ...
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Oops..my bad. Thanked all the replies now.
Will update after flashing rom.