Develop Bugs

[Q] Flashing F400S KDZ on D855?

So there has been an Android L kdz leaked for F400S on xda. Is it possible to flash it on my D855 variant? If it is possible, what's the consequences? Even if there is a high chance of bricking my phone, I'll take my chances.

It won't work unless its ported, the modem, kernel etc are all different.
There is a chance that you could hardware brick the phone by flashing a build designed for different hardware, however, I have not heard of a case on the G3 yet - but my strong advice would be to not even try.

filbertmang said:
So there has been an Android L kdz leaked for F400S on xda. Is it possible to flash it on my D855 variant? If it is possible, what's the consequences? Even if there is a high chance of bricking my phone, I'll take my chances.
Click to expand...
Click to collapse
Do not do it. Not only is there a chance of bricking your device, there's also a huge possibility that you won't be able to get it back to a working state.
There's zero benefit to flashing it, you'll most likely brick your device and the phone won't boot.

Yeah, you can't just flash the F400S KDZ without making some changes. i.e. libs,modem,kernel, etc and even then it may not work. I might be willing to take the plunge. Lol.

[Q] Note 3 User - Moving to LG G3 - Please Help?

Dear LG Friends,
Long time XDA member, coming from the Windows Phone days HTC, then to Android HTC, bunch of Samsungs, and am now thinking about the LG space. More specifically moving from the Note 3 (T-Mobile US) running on the AT&T US, to the LG G3.
Before I do, I need some help from you guys. Which variant should I go for? I know my primary choices will be the T-Mobile and the AT&T variants (I believe they are 851 and 850)? Based on what's important to me, below, can you guys advise which variant to get?:
1. Development Support - Which variant has the MOST amount of Custom ROM options, that is on-going and kept current? I am spoiled with the Note 3, which has a massive development support. I have never tried the LG OS/Skin (escaping me what it's called), but if it's anything like the TouchWiz on Samsungs, I think it will be important to have CM/AOSP/AOKP and etc support.
2. This is related to # 1 - But I heard that only T-Mobile has the unlocked Bootloader? However, doing some research, I believe the AT&T and the Verizon and Sprint variants can also be unlocked? Is this true? If so, are they anymore limited than the factory unlocked T-Mobile variant?
3. LTE bands - I will most likely be using the phone on AT&T US, but if development options/support are higher on other variants, I might consider buying those models, even if they are missing some AT&T bands. For the Note 3 - T-Mobile is a Pentaband phone, meaning it had all the bands needed, so it could easily work on AT&T LTE, all the time. The reverse was not true.
And basically that is it. Initial instinct says to go chase the T-Mobile variant, based on my needs above. But please educate me and help me out if I have missed something. Thank you so much in advance!

Any input guys?

ProFragger said:
Any input guys?
1. Development Support - Which variant has the MOST amount of Custom ROM options, that is on-going and kept current? I am spoiled with the Note 3, which has a massive development support. I have never tried the LG OS/Skin (escaping me what it's called), but if it's anything like the TouchWiz on Samsungs, I think it will be important to have CM/AOSP/AOKP and etc support.
Click to expand...
Click to collapse
If you want OTA updates i suggest sticking with the AT&T variant since you have a valid AT&T sim. If you use a AT&T sim in a T-Mobile variant you wont ever get OTA updates and that means missing out on necessary fixes
1. All 3 US Variants are mostly the same, all have CM12 and all the random obscure AOSP roms as well
2. Well unlocked bootloader isnt that fancy it just means theres fastboot mode compared with the other editions where fastboot mode doesnt work properly even if you enable it. It essentially just makes installing TWRP easier since you dont have to root before installing it unlike other variants
Nevertheless Lollipop can be rooted on all US Variants right now really easily. But the only downside to it is that removing custom roms sometimes can be a pain since you have to use a way where it sometimes works and sometimes doesnt

itsbighead said:
If you want OTA updates i suggest sticking with the AT&T variant since you have a valid AT&T sim. If you use a AT&T sim in a T-Mobile variant you wont ever get OTA updates
1. All 3 US Variants are mostly the same, all have CM12 and all the random obscure AOSP roms as well
2. Well unlocked bootloader isnt that fancy it just means theres fastboot mode compared with the other editions where fastboot mode doesnt work properly even if you enable it
Click to expand...
Click to collapse
Hi Friend,
Thanks for your response, this is very helpful!
No OTA is never a thing I consider. Everything that matters to me, is what I listed already.
So, is the development support (new ROMs, updates and etc) the same for all US variants or would you say one variant is particularly more popular?
As for the locked bootloader, I thought you needed an Unlocked bootloader to flash Custom ROMs, no? It seems like "Bump" fixes this for Verizon, Sprint, and AT&T and gets you TWRP on your phone, but do we need to do extra steps everything to the boot.img for non T-Mobile variants? Or is it a one time mod and then regular flashing and Backups with TWRP?
If it's the same for all variants after Bump, then you're right, I will likely stay with an AT&T variant, thanks to that Band 7 LTE.
Thank you again for your help, hopefully more can chime in !

ProFragger said:
Hi Friend,
Thanks for your response, this is very helpful!
No OTA is never a thing I consider. Everything that matters to me, is what I listed already.
So, is the development support (new ROMs, updates and etc) the same for all US variants or would you say one variant is particularly more popular?
As for the locked bootloader, I thought you needed an Unlocked bootloader to flash Custom ROMs, no? It seems like "Bump" fixes this for Verizon, Sprint, and AT&T and gets you TWRP on your phone, but do we need to do extra steps everything to the boot.img for non T-Mobile variants? Or is it a one time mod and then regular flashing and Backups with TWRP?
If it's the same for all variants after Bump, then you're right, I will likely stay with an AT&T variant, thanks to that Band 7 LTE.
Thank you again for your help, hopefully more can chime in !
Click to expand...
Click to collapse
No need for any steps. Its just install TWRP and your on your way to installing whatever rom you want
Unlocked bootloader means that the system doesnt security (consistency) checks on system partitions
For LG G3, its because someone cracked the encryption for the kitkat android bootloader which means people can sign non stock boot.img without having to worry about unlocking the bootloader.

itsbighead said:
No need for any steps. Its just install TWRP and your on your way to installing whatever rom you want
Unlocked bootloader means that the system doesnt security (consistency) checks on system partitions
For LG G3, its because someone cracked the encryption for the kitkat android bootloader which means people can sign non stock boot.img without having to worry about unlocking the bootloader.
Click to expand...
Click to collapse
Gotcha, thanks again mate! Another (hopefully last) question. If I buy G3, where someone had already OTA'd to 5.0+, will I still be able to root it, install TWRP and get KK ROMs, like CM11 or something?
And vice versa, if the phone comes with KK, do I need to patch with Bump and then I can install ROMs?
Thank you again!

ProFragger said:
Gotcha, thanks again mate! Another (hopefully last) question. If I buy G3, where someone had already OTA'd to 5.0+, will I still be able to root it, install TWRP and get KK ROMs, like CM11 or something?
And vice versa, if the phone comes with KK, do I need to patch with Bump and then I can install ROMs?
Thank you again!
Click to expand...
Click to collapse
You can root it but i dont know if installing TWRP will work. I didnt want to try it incase it doesnt work and it runs the factory reset script instead. That happened to me once before
But i would say just to be sure, downgrade back to KitKat to do it
Yeah, if the phone comes with KitKat just root, install TWRP using root permissions and then your on your way

itsbighead said:
You can root it but i dont know if installing TWRP will work. I didnt want to try it incase it doesnt work and it runs the factory reset script instead. That happened to me once before
But i would say just to be sure, downgrade back to KitKat to do it
Yeah, if the phone comes with KitKat just root, install TWRP using root permissions and then your on your way
Click to expand...
Click to collapse
This is helpful, once again bud. So how would I downgrade back to KK? Would I have to run a stock firmware of some sort? In Samsung, he Flash a .Tar file through their flashing tool called the Odin. Would that be similarly done here?

downgrade 8.0 to 6.0 a520

hi, I'd like to know if there were any way I could revert back to marshmallow without bricking the device. I was thinking about rooting my phone, download the stock a520 6.0 rom zip file and flash it with the recovery menu. First I don't wanna brick it, second I'm not sure I can find some flashable zip file.
I did this with my old Motorola moto g 3 and never had any problems.
do you guys think it'll work and so where I could find those files? also if there's any other safe way to do it share it please!
Thanks in advance!

nubry said:
hi, I'd like to know if there were any way I could revert back to marshmallow without bricking the device. I was thinking about rooting my phone, download the stock a520 6.0 rom zip file and flash it with the recovery menu. First I don't wanna brick it, second I'm not sure I can find some flashable zip file.
I did this with my old Motorola moto g 3 and never had any problems.
do you guys think it'll work and so where I could find those files? also if there's any other safe way to do it share it please!
Thanks in advance!
Click to expand...
Click to collapse
I don't think it will work because Samsung has anti rollback in its phones which prevents the bootloader from being downgraded. However, a system and boot flash might work. I don't know about the modem though.
Samsung is one of the few brands that implement it.
I don't really see the use though as it is quite possible to bootloop and if done incorrectly, could result in a hard brick.

nubry said:
hi, I'd like to know if there were any way I could revert back to marshmallow without bricking the device. I was thinking about rooting my phone, download the stock a520 6.0 rom zip file and flash it with the recovery menu. First I don't wanna brick it, second I'm not sure I can find some flashable zip file.
I did this with my old Motorola moto g 3 and never had any problems.
do you guys think it'll work and so where I could find those files? also if there's any other safe way to do it share it please!
Thanks in advance!
Click to expand...
Click to collapse
Quick question...
Why would you want to?
I did this with my old Moto X Play and bricked it

iloveoreos said:
I don't think it will work because Samsung has anti rollback in its phones which prevents the bootloader from being downgraded. However, a system and boot flash might work. I don't know about the modem though.
Samsung is one of the few brands that implement it.
I don't really see the use though as it is quite possible to bootloop and if done incorrectly, could result in a hard brick.
Click to expand...
Click to collapse
that is what I thought... I think the only real solution would be to find a custom Rom of the Stock 6.0 but untouched. It would not need the bootloader to be downgraded would it?
I really like samsung phones but I hate the way the treat costumers, it feels like being fooled.
Thank you for your reply though !

moozer said:
Quick question...
Why would you want to?
I did this with my old Moto X Play and bricked it
Click to expand...
Click to collapse
When I bought my Moto g 2015 it was very fast and that was surprising. All the updates started to drain the battery and make the device work slower . I tried almost all the custom Rom possible and after flashing back the stock 5.1 out of the box version I have to admit they wanted the device to become slow with all the updates.
Now when I received my A5 it was already running nougat. I think the best you can get from your phone is with the outbox version because everything is planned to be running perfectly so people buy it. For me even though it brings new features and stuff, update wont get you device any better.
So ya that's the reason I'd like to downgrade.

nubry said:
that is what I thought... I think the only real solution would be to find a custom Rom of the Stock 6.0 but untouched. It would not need the bootloader to be downgraded would it?
I really like samsung phones but I hate the way the treat costumers, it feels like being fooled.
Thank you for your reply though !
Click to expand...
Click to collapse
You could extract the system and boot out of the stock firmware, but I don't know if it's worth the risk.

nubry said:
When I bought my Moto g 2015 it was very fast and that was surprising. All the updates started to drain the battery and make the device work slower . I tried almost all the custom Rom possible and after flashing back the stock 5.1 out of the box version I have to admit they wanted the device to become slow with all the updates.
Now when I received my A5 it was already running nougat. I think the best you can get from your phone is with the outbox version because everything is planned to be running perfectly so people buy it. For me even though it brings new features and stuff, update wont get you device any better.
So ya that's the reason I'd like to downgrade.
Click to expand...
Click to collapse
Motorola got in trouble for that. Others too. It's illegal now, so you should leave out that theory.
I've had only positive experiences with my last 5 smartphones. Upgrading does precisely that...makes it better. An OEM would not produce an upgrade without testing it. That's why we had a better experience with Nougat and even better with Oreo.
What do you do differently with Oreo than you did with Nougat?

Has anyone been able to get fastboot access on the G710VM with Android 9.0?

So, I picked up a used G710VM 64GB Storage/4GB RAM, I specifically wanted this model because I'm on Verizon and wanted to ensure that my phone would work with their wack-as-all-hell network. Upon booting it up on the stock firmware for the first time, and intentionally not putting in my SIM, nor getting it online, I saw it using up 16 GBs of storage right out of the gate, and about 2.8 or so GBs of RAM. I thought this unacceptable, and so began my journey of putting custom ROM on it.
I was looking at putting either Lineage OS or AOSP, but both guides require getting TWRP on there first, and that has been my hang-up.
I followed this guide on getting the bootloader unlocked, and got that done.
Now my problem is fastboot mode, with the bootloader unlocked, and on the G710ULM11g firmware, I can get into it just fine. But on the G710EM20b, G710EM20d, and G710ULM20d firmwares I follow the steps to get into fastboot mode, get a warning about the bootloader being unlocked, and then it just does a proper boot up into the OS, every. single. time. And I've gone back and forth between my 8.0 and 9.0 versions of Android a few times, and confirmed it's only the 9.0 ones that are giving me this issue, the 8.0 one lets me in without fail.
Did I unlock the bootloader wrong? Or am I just using the wrong firmware? Has anyone else had luck with a G710VM version of the phone? Or did I hose myself by not buying a ULM or EM version?

Out of appreciation for all the work that everyone in this community does (I read lots but don't post often) I would say, you need to search and skim through at least an hour worth of posts to find that answer, but I'll link it here to say thanks. Short answer- PIE loses Fastboot commands. You can flash to Oreo, and then you should be able to use fastboot commands. I still haven't found a posted method for installing TWRP. I just acquired an 'unlocked' Sprint model with the ULM firmware and would love to explore rom options.
https://forum.xda-developers.com/lg-g7-thinq/how-to/cross-flash-oreo-pie-firmwares-lg-g7-g7-t3915303

In the same guide post if you look on page 6 you will find how people have updated to pie retaining fastboot.
It can also be used to use a pie vm rooted stock rom also.

MaitiuD2 said:
Out of appreciation for all the work that everyone in this community does (I read lots but don't post often) I would say, you need to search and skim through at least an hour worth of posts to find that answer, but I'll link it here to say thanks. Short answer- PIE loses Fastboot commands. You can flash to Oreo, and then you should be able to use fastboot commands. I still haven't found a posted method for installing TWRP. I just acquired an 'unlocked' Sprint model with the ULM firmware and would love to explore rom options.
https://forum.xda-developers.com/lg-g7-thinq/how-to/cross-flash-oreo-pie-firmwares-lg-g7-g7-t3915303
Click to expand...
Click to collapse
Thank you very much for responding.
And that really sucks about fastboot and Pie, now I have to wonder how LameMonster82 did it in his guide . Someone else there tried installing that TWRP from Oreo, and got his phone bricked for it.

Halogen_03 said:
So, I picked up a used G710VM 64GB Storage/4GB RAM, I specifically wanted this model because I'm on Verizon and wanted to ensure that my phone would work with their wack-as-all-hell network. Upon booting it up on the stock firmware for the first time, and intentionally not putting in my SIM, nor getting it online, I saw it using up 16 GBs of storage right out of the gate, and about 2.8 or so GBs of RAM. I thought this unacceptable, and so began my journey of putting custom ROM on it.
I was looking at putting either Lineage OS or AOSP, but both guides require getting TWRP on there first, and that has been my hang-up.
I followed this guide on getting the bootloader unlocked, and got that done.
Now my problem is fastboot mode, with the bootloader unlocked, and on the G710ULM11g firmware, I can get into it just fine. But on the G710EM20b, G710EM20d, and G710ULM20d firmwares I follow the steps to get into fastboot mode, get a warning about the bootloader being unlocked, and then it just does a proper boot up into the OS, every. single. time. And I've gone back and forth between my 8.0 and 9.0 versions of Android a few times, and confirmed it's only the 9.0 ones that are giving me this issue, the 8.0 one lets me in without fail.
Did I unlock the bootloader wrong? Or am I just using the wrong firmware? Has anyone else had luck with a G710VM version of the phone? Or did I hose myself by not buying a ULM or EM version?
Click to expand...
Click to collapse
Weird, I'm using G710EM20d firmware on my G710ULM and it boots to fastboot.

"Weird, I'm using G710EM20d firmware on my G710ULM and it boots to fastboot."
-----------------------------------------------------------------------------------------
I have the ULM model as well but the G710EM20d Model doesnt boot to fastboot. Could you tell me the KDZ file you used?
Example, "G710EM10b_00_0521.kdz"
I'd really appreciate the help

u should cross flash the ulm firmware by lg up and then boot ur device in to the download mode after erase laf partition

LG G8 Thinq Sprint Model - Update from A9-A10

I have the LG G8 Thinq Sprint Model (LM-G820UMKIT) bought it pre-owned. I recently saw that there was a guide to unlock and root the LG G8 however the requirements is for the device to be on Android 10. I'm currently still on Android 9 and I am unable to update via software update, or through LG Suite. Is there anyway to update to A10?

Adelino80 said:
I have the LG G8 Thinq Sprint Model (LM-G820UMKIT) bought it pre-owned. I recently saw that there was a guide to unlock and root the LG G8 however the requirements is for the device to be on Android 10. I'm currently still on Android 9 and I am unable to update via software update, or through LG Suite. Is there anyway to update to A10?
Click to expand...
Click to collapse
It's unfortunate, but the guide is a bit misleading. I'd bet the person that wrote it had a specific version of android, and didn't know / want to indicate it would work on any other as they hadn't tested it.
But, there's virtually zero reason the unlock procedure shouldn't work on any version of android. The reason is very simple; all you do in that guide is use edl mode (any qualcomm device can do that), you flash the engineering abl to abl partition (it won't matter what version of android the rest of the system is), you go to fastboot (that's what the eng abl gives you), you unlock the boot-loader, you use fastboot to flash the original abl back.
Makes sense? See, you don't use that eng abl to boot the OS, you don't use it for anything at all, except to unlock the boot-loader. That's it. Period. There's no reason for it to not work no matters what version of android your system is.
As far as Sprint update goes... talk to sprint, ask them for help getting it updated. Sprint does not make their kdz available, if you don't get any OTA update from them, you'll then be faced with finding someone's partition backup, and all the complications involved / and danger, of flashing that.
The other option would be to crossflash to a rom that has a kdz. It too is involved and complicated, and potentially dangerous.
good luck

AsItLies said:
It's unfortunate, but the guide is a bit misleading. I'd bet the person that wrote it had a specific version of android, and didn't know / want to indicate it would work on any other as they hadn't tested it.
But, there's virtually zero reason the unlock procedure shouldn't work on any version of android. The reason is very simple; all you do in that guide is use edl mode (any qualcomm device can do that), you flash the engineering abl to abl partition (it won't matter what version of android the rest of the system is), you go to fastboot (that's what the eng abl gives you), you unlock the boot-loader, you use fastboot to flash the original abl back.
Makes sense? See, you don't use that eng abl to boot the OS, you don't use it for anything at all, except to unlock the boot-loader. That's it. Period. There's no reason for it to not work no matters what version of android your system is.
As far as Sprint update goes... talk to sprint, ask them for help getting it updated. Sprint does not make their kdz available, if you don't get any OTA update from them, you'll then be faced with finding someone's partition backup, and all the complications involved / and danger, of flashing that.
The other option would be to crossflash to a rom that has a kdz. It too is involved and complicated, and potentially dangerous.
good luck
Click to expand...
Click to collapse
Thanks for the advice! Yeah I wouldn't see why the device shouldn't be able to boot into EDL mode. I don't mind trying the unlock procedure with the guide, just sucks that there is no MSM tool to unbrick the device if anything does happen. As for updating to A10 I can live without, I only asked because the guide specified A10 as an requirement, which you already answered.

Adelino80 said:
Thanks for the advice! Yeah I wouldn't see why the device shouldn't be able to boot into EDL mode. I don't mind trying the unlock procedure with the guide, just sucks that there is no MSM tool to unbrick the device if anything does happen. As for updating to A10 I can live without, I only asked because the guide specified A10 as an requirement, which you already answered.
Click to expand...
Click to collapse
I would suggest that you look at the bkerler edl tools. Don't do anything until you backed up the device completely.