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[** H815EUR ** ONLY] Bootloader Unlock-/Relock Guide

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blake_spector

Senior Member
Nov 29, 2008
70
73
G4 ** H815EUR **
Bootloader Unlock-/Relock Guide

* DISCLAIMER
Read carefully before proceeding !

Doing this will void your warranty and can permanently damage your device !
You take full responsibility if you brick your phone !
Only proceed at your own risk !

* REQUIREMENTS
All the things you need . . .


* STEP 0
Get the Device-ID for generating unlock.bin file !

  • Reboot the phone into fastboot mode - in cmd.exe type
    Code:
    adb reboot bootloader
  • Show the Device-ID for unlock.bin request !
    Code:
    fastboot oem device-id
  • Show current bootloader state !
    Code:
    fastboot getvar unlocked
    > unlocked: no
  • Reboot the phone . . .
    Code:
    fastboot reboot

Mnv5pNs.jpg


* STEP 1
Enable send_command.exe to backup the partition data !

  • Start LGUP to enable send_command.exe - NOTE - make sure to select ** UPGRADE **
  • Start flashing and prepare to pull the USB cable to disconnect the phone . . .
  • Disconnect the phone as soon as COM appears on the display !
  • Close LGUP and reconnect the phone . . .

oERN5nw.jpg


* STEP 2
Backup the drm, misc and persistent partitions !

  • In cmd.exe navigate to send_command.exe and enter
    Code:
    send_command.exe \\.\[COLOR="Green"]COM[your port number here][/COLOR]
  • Dump the partitions to the internal storage of the phone . . .
    Code:
    dd if=/dev/block/mmcblk0 of=/data/media/0/drm.img bs=512 skip=655360 count=16384
    dd if=/dev/block/mmcblk0 of=/data/media/0/misc.img bs=512 skip=262144 count=32768
    dd if=/dev/block/mmcblk0 of=/data/media/0/persistent.img bs=512 skip=380928 count=4096
  • For safety, make a full dump of all partitions !
    Code:
    dd if=/dev/block/mmcblk0 of=/data/media/0/full_dump.img bs=4096 count=1552384
  • Set the permissions and owner for the files !
    Code:
    chown -R media_rw:media_rw /data/media/0
    chmod -R 0666 /data/media/0
  • Partition dump complete ! To finish enter
    Code:
    LEAVE
  • Remove the battery and restart the phone . . .

hc4W19C.jpg


* STEP 3
Copy the drm, misc and persistent partition images to your computer and/or SD card !

  • Check the file size of the partition images !
    Code:
    [B][COLOR="Magenta"]drm.img[/COLOR][/B] = [B]8.00 MB[/B] (8.388.608 Bytes)
    [B][COLOR="Magenta"]misc.img[/COLOR][/B] = [B]16.00 MB[/B] (16.777.216 Bytes)
    [B][COLOR="magenta"]persistent.img[/COLOR][/B] = [B]2.00 MB[/B] (2.097.152 Bytes)
  • Copy all files (including full_dump.img) to your computer and/or SD card !
  • - NOTE - the next step (bootloader unlock) ** WILL ERASE ALL USERDATA ** so make sure to backup your data before proceeding !

uYOETAW.jpg


* STEP 4a
Unlock the bootloader with official method and the generated unlock.bin from LG . . .

  • Reboot the phone into fastboot mode - in cmd.exe type
    Code:
    adb reboot bootloader
  • Navigate to unlock.bin and unlock your bootloader !
    Code:
    fastboot flash unlock unlock.bin
  • Reboot the phone . . .
    Code:
    fastboot reboot

keqe4EF.jpg


* STEP 4b (optional)
Show/confirm the unlocked bootloader state . . .

  • - NOTE - the unlocked bootloader is indicated by Bootloader state : Bootloader unlocked ! ! in the upper left corner when booting the device !
  • Reboot the phone into fastboot mode - in cmd.exe type
    Code:
    adb reboot bootloader
  • Show current bootloader state !
    Code:
    fastboot getvar unlocked
    > unlocked: yes
  • Reboot the phone . . .
    Code:
    fastboot reboot

* STEP 5a
Flash the backup partitions drm, misc and persistent to relock the bootloader !

  • Copy the partition files drm.img, misc.img and persistent.img from your computer or SD card to the internal storage of the phone !
  • Repeat * STEP 1 . . .
  • In cmd.exe navigate to send_command.exe and enter
    Code:
    send_command.exe \\.\[COLOR="Green"]COM[your port number here][/COLOR]
  • Again, set the permissions and owner for the files !
    Code:
    chown -R media_rw:media_rw /data/media/0
    chmod -R 0666 /data/media/0
  • Flash the partitions from the internal storage of the phone . . .
    Code:
    dd if=/data/media/0/drm.img of=/dev/block/mmcblk0 bs=512 seek=655360 count=16384
    dd if=/data/media/0/misc.img of=/dev/block/mmcblk0 bs=512 seek=262144 count=32768
    dd if=/data/media/0/persistent.img of=/dev/block/mmcblk0 bs=512 seek=380928 count=4096
  • Bootloader relock complete ! To finish enter
    Code:
    LEAVE
  • Remove the battery and restart the phone . . .

0GnA0hd.jpg


* STEP 5b (optional)
Show/confirm the relocked bootloader state . . .

  • - NOTE - The indication Bootloader state : Bootloader unlocked ! ! in the upper left corner should no longer appear !
  • Reboot the phone into fastboot mode - in cmd.exe type
    Code:
    adb reboot bootloader
  • Show current bootloader state !
    Code:
    fastboot getvar unlocked
    > unlocked: no
  • Reboot the phone . . .
    Code:
    fastboot reboot

AmB7jJn.jpg


---
Personal thanks to @letama for the help, testing and support!
Credits to @OllieD (https://forum.xda-developers.com/g4/general/relocking-bootloader-t3380781) and @xVANKO (https://forum.xda-developers.com/g4/general/h815-relock-bootloader-t3506634) for the development!
 
Last edited:

re_di

Senior Member
May 3, 2011
170
21
What about H818P European version?

Wysłane z mojego LG-H818 przy użyciu Tapatalka
 

Drenabrab

Senior Member
Feb 7, 2012
67
26
Trani
I've unlocked bootloader with old and official method so now I don't have any backup. Can I relock bootloader? Thank you for your excelent work
 
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equiliym

Senior Member
Nov 15, 2010
368
89
Mellieha
thanks dude, might give this a try, recently got my unlocked device returned from bootloop repair totally locked and going crazy with the stock rom
 

bongster

Senior Member
Jun 7, 2012
190
43
Thank you for this!

Regarding step 1, is this only for the COM port determination?
If i remember right the com port is also shown in the device manager (windows) when the phone is connected via usb.
 

Engelm

Senior Member
Feb 11, 2015
96
33
This procedure treats about both lock and relock bootloader, so I thought that hopefully may work on 818p Eur version too.

Wysłane z mojego LG-H818 przy użyciu Tapatalka

It is about unlocking with the official BL unlock (LG-Website).
The only way is to dig into what xVANKO said.
Analyze the partitions before & after, modify them, pray and restore.
If someone would try it I would be happy because we haven't heard anything from him for a long time
and he also has the idea to relock/unlock the devices in exactly this way.
 

HallEx

Member
Sep 27, 2012
36
16
Hello blake_spector,

Thank's for your tutorial ! Look like amazing because i have the G4 since more than one year and get stuck on official ROM is so borring..

But i've a question, i bought my LG G4 in France (i'm french) and it's a H815 but how to see if it can be unlocked/relock ? On imeidata.net there is thoose informations :

Model : LGH815
Suffix: AFRAVK
Chip Type: EG
Network Code: FRA

Thank's a lot :)
 

uio88

Senior Member
Apr 19, 2009
139
45
Maaaaaan you're amazing! The man of the year!!! Thank you, and we say all together, f**k lg haahahah :D
 

HallEx

Member
Sep 27, 2012
36
16
It's ok. Mine is FRA too, I did unlock and relock without any issue.

Hello, ohhh yes ! It's a cool news ! After more than one year go to unlock my G4 ! No bootloop but bad battery life hope to get a rom like Samsung S7/Edge with a possibilty to change resolution like 1080P !

Which rom did u install ? :)
 

andrea1493

Senior Member
Mar 5, 2015
75
13
Taranto
I've already dumped my partitions before unlocking with these commands:

dd if=/dev/block/mmcblk0 bs=8192 skip=585216 count=32768 of=/data/media/0/cust.img
dd if=/dev/block/mmcblk0 bs=8192 skip=16384 count=2048 of=/data/media/0/misc.img
dd if=/dev/block/mmcblk0 bs=8192 skip=40960 count=1024 of=/data/media/0/drm.img
dd if=/dev/block/mmcblk0 bs=8192 skip=43008 count=4096 of=/data/media/0/mpt.img
dd if=/dev/block/mmcblk0 bs=8192 skip=41984 count=1024 of=/data/media/0/sns.img
dd if=/dev/block/mmcblk0 bs=8192 skip=23808 count=256 of=/data/media/0/persistent.img
dd if=/dev/block/mmcblk0 bs=8192 skip=22528 count=192 of=/data/media/0/modemst1.img
dd if=/dev/block/mmcblk0 bs=8192 skip=22720 count=192 of=/data/media/0/modemst2.img

Does they are equivalent?

P.S. I have H815 ITALY LG G4
 

Minto107

Senior Member
Aug 10, 2013
3,937
1,385
21
Hello, ohhh yes ! It's a cool news ! After more than one year go to unlock my G4 ! No bootloop but bad battery life hope to get a rom like Samsung S7/Edge with a possibilty to change resolution like 1080P !

Which rom did u install ? :)
Maybe little off topic but you could already get down to 1080p even without root ;) just adb commands ;)
Thanks blake I was waiting for this moment since I bought my G4 :D tomorrow I'll do all the things and report back ;)
Is send command compatible with USB 3.0?(I had some bluescreens during unlocks on my HTC phones) Can someone post a command for dumping data partition(one that stores all my things, apps etc)
 
Y

yener90

Guest
Guys should I wait for nougat because of bootloader etc update or should i unlock now?
The main problem is that maybe they fix this gap...
 

Mess35

New member
Jan 6, 2017
2
0
Hi !

Thank you very much for this guide, I'm waiting for this since I upgraded to stock MM, which has caused me to lose root on my G4 :(

However I couldn't do the step 3 because I don't find the partition images created during step 2.
Where are they supposed to be found ?
In the root of the internal memory, when I plug the phone in my computer or via en explorer app like Solid Explorer ?

My guess is the dd commands that create the partition files failed and the images were not created.

The first time I used the command to create drm.img, it seems that it takes forever (20~30mn+) so I'm forced to Ctrl + C.
When I execute the command again, I get the # prompt in like 2 seconds. The following dd commands last 2 seconds also.
But when I reboot the phone, I don't see any img files on my internal memory.

I tried to redo the Step 2 after rebooting, but the commands still lasts 2 seconds.

What did I miss ?
How long the dd commands are supposed to take ?
Is there some sort of requirements to succeed ?

I have of course a H815, 20i image flashed by OTA, I never messed with the bootloader, have 11 GB of free memory on Internal Memory.
My internal memory is also encrypted.

Thank you very much
 
Last edited:

HallEx

Member
Sep 27, 2012
36
16
Hi !

Thank you very much for this guide, I'm waiting for this since I upgraded to stock MM, which has caused me to lose root on my G4 :(

However I couldn't do the step 3 because I don't find the partition images created during step 2.
Where are they supposed to be found ?
In the root of the internal memory, when I plug the phone in my computer or via en explorer app like Solid Explorer ?

My guess is the dd commands that create the partition files failed and the images were not created.

The first time I used the command to create drm.img, it seems that it takes forever (20~30mn+) so I'm forced to Ctrl + C.
When I execute the command again, I get the # prompt in like 2 seconds. The following dd commands last 2 seconds also.
But when I reboot the phone, I don't see any img files on my internal memory.

I tried to redo the Step 2 after rebooting, but the commands still lasts 2 seconds.

What did I miss ?
How long the dd commands are supposed to take ?
Is there some sort of requirements to succeed ?

I have of course a H815, 20i image flashed by OTA, I never messed with the bootloader, have 11 GB of free memory on Internal Memory.
My internal memory is also encrypted.

Thank you very much

Hello,

I have the same problem, i'm stuck on the 2nd step since 2 hours.

After LGUP restart to "COM4" i disconnect the phone and try to dump partitions but nothing special. Every command his finish in 1sec. The phone reboot when i'm at the "LEAVE" command and restart on a new install of my firmware ! Lost all my app (but already get a backup before)
I don't find any backup in the files manager, there is nothing.

For the moment i'm like you, at the same step... Hope to find a way to resolve the problem :(
 

Minto107

Senior Member
Aug 10, 2013
3,937
1,385
21
Guys should I wait for nougat because of bootloader etc update or should i unlock now?
The main problem is that maybe they fix this gap...
No reason to wait. If you will like to relock, just get back on MM(not sure if LG will change the partitions on nougat so for now better to get back) and if you wish, upgrade to nougat again ;)
 

blake_spector

Senior Member
Nov 29, 2008
70
73
Hi !

Thank you very much for this guide, I'm waiting for this since I upgraded to stock MM, which has caused me to lose root on my G4 :(

However I couldn't do the step 3 because I don't find the partition images created during step 2.
Where are they supposed to be found ?
In the root of the internal memory, when I plug the phone in my computer or via en explorer app like Solid Explorer ?

My guess is the dd commands that create the partition files failed and the images were not created.

The first time I used the command to create drm.img, it seems that it takes forever (20~30mn+) so I'm forced to Ctrl + C.
When I execute the command again, I get the # prompt in like 2 seconds. The following dd commands last 2 seconds also.
But when I reboot the phone, I don't see any img files on my internal memory.

I tried to redo the Step 2 after rebooting, but the commands still lasts 2 seconds.

What did I miss ?
How long the dd commands are supposed to take ?
Is there some sort of requirements to succeed ?

I have of course a H815, 20i image flashed by OTA, I never messed with the bootloader, have 11 GB of free memory on Internal Memory.
My internal memory is also encrypted.

Thank you very much

Hello,

I have the same problem, i'm stuck on the 2nd step since 2 hours.

After LGUP restart to "COM4" i disconnect the phone and try to dump partitions but nothing special. Every command his finish in 1sec. The phone reboot when i'm at the "LEAVE" command and restart on a new install of my firmware ! Lost all my app (but already get a backup before)
I don't find any backup in the files manager, there is nothing.

For the moment i'm like you, at the same step... Hope to find a way to resolve the problem :(

I added a picture of 3rd step, the partition images should be in the root of the internal storage and accessible with the stock LG file manager.

uYOETAW.jpg


I'm not sure what you might have missed, as I composed the guide from a continuous screengrab and video record of me doing the process. :confused:
The dd commands for drm, misc, persistent shouldn't take longer than 1sec (as they are only 8, 16 and 2 MB), the dd command for full_dump (~6 GB) might take a few minutes.

My internal memory is also encrypted.

That could be a problem, in my example the internal storage is/was not encrypted!

You could try to use LGUP and refurbish (!) to a fresh starting point (I used this KDZ https://forum.xda-developers.com/g4/general/kdz-firmware-v20j-united-kingdom-2016-t3518925) before doing the process.
OFC backup all your data first, as this will perform a complete reset of the device.
 
Last edited:
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  • 24
    G4 ** H815EUR **
    Bootloader Unlock-/Relock Guide

    * DISCLAIMER
    Read carefully before proceeding !

    Doing this will void your warranty and can permanently damage your device !
    You take full responsibility if you brick your phone !
    Only proceed at your own risk !

    * REQUIREMENTS
    All the things you need . . .


    * STEP 0
    Get the Device-ID for generating unlock.bin file !

    • Reboot the phone into fastboot mode - in cmd.exe type
      Code:
      adb reboot bootloader
    • Show the Device-ID for unlock.bin request !
      Code:
      fastboot oem device-id
    • Show current bootloader state !
      Code:
      fastboot getvar unlocked
      > unlocked: no
    • Reboot the phone . . .
      Code:
      fastboot reboot

    Mnv5pNs.jpg


    * STEP 1
    Enable send_command.exe to backup the partition data !

    • Start LGUP to enable send_command.exe - NOTE - make sure to select ** UPGRADE **
    • Start flashing and prepare to pull the USB cable to disconnect the phone . . .
    • Disconnect the phone as soon as COM appears on the display !
    • Close LGUP and reconnect the phone . . .

    oERN5nw.jpg


    * STEP 2
    Backup the drm, misc and persistent partitions !

    • In cmd.exe navigate to send_command.exe and enter
      Code:
      send_command.exe \\.\[COLOR="Green"]COM[your port number here][/COLOR]
    • Dump the partitions to the internal storage of the phone . . .
      Code:
      dd if=/dev/block/mmcblk0 of=/data/media/0/drm.img bs=512 skip=655360 count=16384
      dd if=/dev/block/mmcblk0 of=/data/media/0/misc.img bs=512 skip=262144 count=32768
      dd if=/dev/block/mmcblk0 of=/data/media/0/persistent.img bs=512 skip=380928 count=4096
    • For safety, make a full dump of all partitions !
      Code:
      dd if=/dev/block/mmcblk0 of=/data/media/0/full_dump.img bs=4096 count=1552384
    • Set the permissions and owner for the files !
      Code:
      chown -R media_rw:media_rw /data/media/0
      chmod -R 0666 /data/media/0
    • Partition dump complete ! To finish enter
      Code:
      LEAVE
    • Remove the battery and restart the phone . . .

    hc4W19C.jpg


    * STEP 3
    Copy the drm, misc and persistent partition images to your computer and/or SD card !

    • Check the file size of the partition images !
      Code:
      [B][COLOR="Magenta"]drm.img[/COLOR][/B] = [B]8.00 MB[/B] (8.388.608 Bytes)
      [B][COLOR="Magenta"]misc.img[/COLOR][/B] = [B]16.00 MB[/B] (16.777.216 Bytes)
      [B][COLOR="magenta"]persistent.img[/COLOR][/B] = [B]2.00 MB[/B] (2.097.152 Bytes)
    • Copy all files (including full_dump.img) to your computer and/or SD card !
    • - NOTE - the next step (bootloader unlock) ** WILL ERASE ALL USERDATA ** so make sure to backup your data before proceeding !

    uYOETAW.jpg


    * STEP 4a
    Unlock the bootloader with official method and the generated unlock.bin from LG . . .

    • Reboot the phone into fastboot mode - in cmd.exe type
      Code:
      adb reboot bootloader
    • Navigate to unlock.bin and unlock your bootloader !
      Code:
      fastboot flash unlock unlock.bin
    • Reboot the phone . . .
      Code:
      fastboot reboot

    keqe4EF.jpg


    * STEP 4b (optional)
    Show/confirm the unlocked bootloader state . . .

    • - NOTE - the unlocked bootloader is indicated by Bootloader state : Bootloader unlocked ! ! in the upper left corner when booting the device !
    • Reboot the phone into fastboot mode - in cmd.exe type
      Code:
      adb reboot bootloader
    • Show current bootloader state !
      Code:
      fastboot getvar unlocked
      > unlocked: yes
    • Reboot the phone . . .
      Code:
      fastboot reboot

    * STEP 5a
    Flash the backup partitions drm, misc and persistent to relock the bootloader !

    • Copy the partition files drm.img, misc.img and persistent.img from your computer or SD card to the internal storage of the phone !
    • Repeat * STEP 1 . . .
    • In cmd.exe navigate to send_command.exe and enter
      Code:
      send_command.exe \\.\[COLOR="Green"]COM[your port number here][/COLOR]
    • Again, set the permissions and owner for the files !
      Code:
      chown -R media_rw:media_rw /data/media/0
      chmod -R 0666 /data/media/0
    • Flash the partitions from the internal storage of the phone . . .
      Code:
      dd if=/data/media/0/drm.img of=/dev/block/mmcblk0 bs=512 seek=655360 count=16384
      dd if=/data/media/0/misc.img of=/dev/block/mmcblk0 bs=512 seek=262144 count=32768
      dd if=/data/media/0/persistent.img of=/dev/block/mmcblk0 bs=512 seek=380928 count=4096
    • Bootloader relock complete ! To finish enter
      Code:
      LEAVE
    • Remove the battery and restart the phone . . .

    0GnA0hd.jpg


    * STEP 5b (optional)
    Show/confirm the relocked bootloader state . . .

    • - NOTE - The indication Bootloader state : Bootloader unlocked ! ! in the upper left corner should no longer appear !
    • Reboot the phone into fastboot mode - in cmd.exe type
      Code:
      adb reboot bootloader
    • Show current bootloader state !
      Code:
      fastboot getvar unlocked
      > unlocked: no
    • Reboot the phone . . .
      Code:
      fastboot reboot

    AmB7jJn.jpg


    ---
    Personal thanks to @letama for the help, testing and support!
    Credits to @OllieD (https://forum.xda-developers.com/g4/general/relocking-bootloader-t3380781) and @xVANKO (https://forum.xda-developers.com/g4/general/h815-relock-bootloader-t3506634) for the development!
    10
    I got the same problem. I have nor backup of these files if i unlocked it in summer last year. No chance for people like us?

    I have already RELOCKED phones with no backup partitions - not only EU variant.
    BTW - im still developing app to make this process automated (for all devices listed here: LINK)

    ---------- Post added at 04:03 AM ---------- Previous post was at 03:58 AM ----------

    Step 1 circumvents MM security measures to enable the use of send_command.exe!
    For that 9%, as far as we should be concernced . . . let's just say it simply enables stuff to follow the steps.
    Because I don't have a better answer, see it as "why does the apple fall from the tree - because gravity". ;)

    blake_spector - great job with this tutorial but: you NEED to include 1 VERY IMPORTANT information ;)

    Relocking can be done ONLY using the same OS version!!!
    In example: if somebody is using v20b, than he unlock his bootloader, flash v20e HE CANT RELOCK BOOTLOADER TILL HE FLASH v20B back- if he try to flash backup files from v20b into v20e rom, he will brick his phone permamently!
    9
    That's interesting, you did that by comparing locked and unlocked partitions then modifying unlocked ones to look like locked?

    MISC partition is like "Database of Switches" which contains only 1 stupid switch related to bootloader called "unlocked" - LG employee which created this method of locking bootloader should be fired - but its good for us.

    ---------- Post added at 09:14 AM ---------- Previous post was at 09:12 AM ----------

    I got it with your method, I locked my bootloader, but only on the misc, and cust partitions are saved, and then put it back in, and the way the lock works. Isn't it possible that just the misc partition, the close?

    CUST partition contains "Unlock Key" which was used in unlocking process. If device detect that there is a valid Unlock Key, it will unlock your device again - so you need to flash CUST and MISC. Persistent partition is not needed.

    ---------- Post added at 09:19 AM ---------- Previous post was at 09:14 AM ----------

    Also no backup of those partitions.
    From what ill read they must match the correct firmware and DEVICE-ID?

    Can anybody confirm this?
    Have unlocked my phone and now i have this ****ty screen burn in of my status bar.

    thx
    pOpY

    Im finishing my app to relock lg without backup
    For screen burning use this app: https://www.androidpit.com/how-to-fix-screen-burn-in
    Keep it enabled for 8 hours with max brightness of screen to makes the pixels "exercise" and that's all
    6
    I was able to lock my device with ease and without having any previous dump.

    If someone wants to test it.. There are no guanrantees. But the method should work for anyone..

    I made a flashable zip for it. It would even work without loosing your current userdata or system partition... If using the same firmware version of the kdz.

    The process is simple..
    When you flash a KDZ the partitions responsible for unlocking will be handled different. I'm not sure what's exactly happening there so I cannot say for sure if they just be left out or some kind of other things (automatic re-unlock?) happening here.
    But what I can say is.. If you flash ALL (except system and user data if you don't want to) partitions from a kdz MANUALLY the device is locked again.

    So.. Again it worked for me and well it is like flashing a regular kdz so it should be safe to use but well no guarantees.

    There's only one thing which is required: anti rollback version. Afaik this is something on the h811 only but this should be checked before using that method.

    If someone wants to test.. Lemme know..


    Update:

    Flashing misc is enough to re-lock!
    Keep in mind that relocking requires a full stock device before!

    Also consider to use my download mode backup here: https://tinyurl.com/dlbackup



    .



    Sent from my LG-H815 using XDA Labs
    5
    I just wanna ask about H818P/N Bootloader Unlock, Is it Possible, Did you achieved it ??

    Hope you did

    yes

    ---------- Post added at 03:18 PM ---------- Previous post was at 03:16 PM ----------

    Sweet, thanks! What are the risks involved doing it without a backup? Do I need the exact same version of android that was installed? Any bootloop chances? And or will I lose eg, the EMEI? I need to know in regards that I need to return the phone, and I merely wish to remove the unlocked bootloader message. Only have a few days left before I need to return it :) so I really appreciate all the help I can get!

    No risk "probably" ;)
    Yes - you need same version of android installed.
    No bootloops
    No loosing IMEI
    Fastboot returns bootloader state "LOCKED" so its not only visual relock