Successfully de-brand AT&T Lumia 1020!

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e-Pig

Member
Apr 24, 2010
7
9
Finally de-brand AT&T Lumia 1020 (RM-877) successfully, this method may also work on any other Lumia Windows Phone!

Warning: This method is not fully tested, may brick your phone! Back up all data, and do not use this method to flash any incompatible ROMs!


Method A
  1. Update your AT&T Lumia 1020 to Windows 10 mobile and interop unlock it.
  2. Change the registry value of “DataStore” to “C:\EFIESP\efi\Nokia” in “HKLM\SOFTWARE\Microsoft\MTP”.
  3. Connect the phone to PC, open “Phone\PCONF”, copy “config.pcn” to your HDD and use a HEX editor to open it.
  4. Change P5217_ATT (HEX: 50 35 32 31 37 5F 41 54 54) to P5217 (HEX: 50 35 32 31 37 00 00 00 00) at offset 0x10, then save it.
  5. Copy modified “config.pcn” back to “Phone\PCONF” and overwrite it.
  6. Restart your phone and use flashing tools like “thor2.exe” to flash unbranded RM-875 rom!
Method B
  1. Download the update cab (Lumia 1020 ONLY)
    Then copy the cab file to an empty folder, e.g. “c:\cab”.
  2. Download and install the tools (Thanks WojtasXda!)
  3. Connect the phone to PC, then run cmd and go to “iutool.exe” folder (default: Program Files (x86)\Windows Phone Kits\8.1\Tools\bin\i386), type
    Code:
    iutool.exe -p c:\cab -V
    The phone should restart and install updates automatically (ignore ERROR: 0x8024a110)
  4. Flash unbranded RM-875 rom!
My AT&T Lumia 1020 is carrier unlocked, the method does not relock my phone.

We knew AT&T changed the Platform ID (P5217_ATT) to avoid flashing RM-875 rom (P5217). The flashing tools check the platform info values of the phone and the DevicePlatformID string from the rom. Lumia 635/820 has SD card, and the device info in the registry can be changed. After the phone checking and installing updates, it is unbranded. Thus the updates can change the Platform ID info of the phone. (Thanks pankaj981 for this guide)
I find the update cabs of an unbranded RM-876 phone (flashed RM-875 rom). Then using the iutool.exe to update AT&T RM-877 manually. After that, I flashed RM-877 with RM-875 rom successfully (Method B). Finally, I find “config.pcn” contains Platform ID. Thus for an interop unlocked phone, Method A may be easier.

Post here if you have any questions!
 

qodexc

Member
Nov 7, 2015
13
4
Lumia 640 AT&T

I can't seem to find the config.pcn on Lumia 640 AT&T, but I got access to EFIESP by using "C:\EFIESP" or "\EFIESP" (both work) for the DataStore.

I see from another forum users can edit the xml files found in "Windows Phone\Phone\Windows\Packages\DsmFiles", so is there anything else I can edit to remove the _ATT for Lumia 640 AT&T?
 

e-Pig

Member
Apr 24, 2010
7
9
I can't seem to find the config.pcn on Lumia 640 AT&T, but I got access to EFIESP by using "C:\EFIESP" or "\EFIESP" (both work) for the DataStore.

I see from another forum users can edit the xml files found in "Windows Phone\Phone\Windows\Packages\DsmFiles", so is there anything else I can edit to remove the _ATT for Lumia 640 AT&T?


I've download the AT&T 940 rom (RM1073_059X0B8), and I find file "pconf.bin" in "PLAT" partition has the infomation about platform ID; but i'm not sure whether the modified file takes effect.
Code:
NAME=P6204_ATT
SWVERSION=02177.00000.15184.36000

To access "PLAT" partition ,the drive letter may need to be assigned. The information about mounted drive is in registry "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices"
But the registry editors like vcREG have the limit:
binary: when you read, the app will return 20 bytes, regardless of how long the binary is.
The key is stored in binary and may be longer than 20 bytes.
The "PLAT" partition is FAT12, I don't know if W10M were able to read it.

If you have an international Lumia 940 and it have a lower ROM version, you could use Fiddler to find all the update cabs like this.
If there is one which has the Platform ID, you could use iutool to update your AT&T 640 with that cab. This may be a lot work to do.

If just using the way here then updating to W10M?
Lumia 640 has SD card, and the DeviceTargetInfo can be edited in WP8.1. If the edited AT&T 640 was updated to W10M, the Platform ID may be changed. I'm not sure, but this seems easy to try.
 

qodexc

Member
Nov 7, 2015
13
4
I've download the AT&T 940 rom (RM1073_059X0B8), and I find file "pconf.bin" in "PLAT" partition has the infomation about platform ID; but i'm not sure whether the modified file takes effect.
Code:
NAME=P6204_ATT
SWVERSION=02177.00000.15184.36000

To access "PLAT" partition ,the drive letter may need to be assigned. The information about mounted drive is in registry "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices"
But the registry editors like vcREG have the limit:

The key is stored in binary and may be longer than 20 bytes.
The "PLAT" partition is FAT12, I don't know if W10M were able to read it.

If you have an international Lumia 940 and it have a lower ROM version, you could use Fiddler to find all the update cabs like this.
If there is one which has the Platform ID, you could use iutool to update your AT&T 640 with that cab. This may be a lot work to do.

If just using the way here then updating to W10M?
Lumia 640 has SD card, and the DeviceTargetInfo can be edited in WP8.1. If the edited AT&T 640 was updated to W10M, the Platform ID may be changed. I'm not sure, but this seems easy to try.

It's definitely that pconf.bin values that needs to be edited. That plat partition is preventing me from flashing other roms, I'm getting "image targeting check failed Device: Nokia.MSM8926.P6204_ATT.1.1, Image: Nokia.MSM8926.P6204". I tried updating to Windows 10 with modified DeviceTargetInfo, but I still get this error when I try to flash a CV rom.

I don't think I can edit the registry for "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices", it showed something like "system.[]" for value. I think the only way is for someone to provide an international 640 platformid cab and use iutool.
 

e-Pig

Member
Apr 24, 2010
7
9
It's definitely that pconf.bin values that needs to be edited. That plat partition is preventing me from flashing other roms, I'm getting "image targeting check failed Device: Nokia.MSM8926.P6204_ATT.1.1, Image: Nokia.MSM8926.P6204". I tried updating to Windows 10 with modified DeviceTargetInfo, but I still get this error when I try to flash a CV rom.

I don't think I can edit the registry for "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices", it showed something like "system.[]" for value. I think the only way is for someone to provide an international 640 platformid cab and use iutool.

It seems that this registry editor can read/write binary values. But I don't have W10M phone now to test it.

PS. I tested the ffu vhd on PC. The Plat partition is hidden, it is not work even if you write the information about assigning drive letter in HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices. The drive letter will not appear until the hidden attribute been clear. It is hard to edit partition attribute on a phone. Maybe the only way is getting a cab that updating the Platform ID.
 

qodexc

Member
Nov 7, 2015
13
4
Thanks for testing and confirming the registry method doesn't work. Well there is nothing to do but wait for a .cab file.
 

Wack0Distractor

Senior Member
Jan 10, 2013
50
74
Don't **** with the PLAT partition unless you know what you are doing.

I know someone who applied an update to PLAT partition that wasn't for their device, and doing that hard bricked it.
 

pankaj981

Senior Member
Dec 24, 2008
71
3
Columbus, OH
One thing you could try is modifying the exact same registry keys for the RM-977 as mentioned in my thread here. Now the only reason the update will kick in is if the OS/firmware version is lower than what's on your device.
 

booker50rus

Member
Jan 6, 2016
15
7
Hello! When using method # 2 I get the message:

[1] Started device **********************************
[1] Transferring files started
[1] Transferred file 1/4
[1] Transferred file 2/4
[1] Transferred file 3/4
[1] Transferred file 4/4
[1] Transferring files complete: 4 files
[1] Update started
[1] Installation failed (HRESULT = 0x801882c1)
[1] Failed (0x801882c1)
ERROR: 0x801882c1
Command failed. (HRESULT = 0x801882c1)

Using Windows 10 Pro. On Windows phone 8.1 update 1

Help in this issue please
 

Zilog8

Member
Oct 2, 2011
11
1
It works.

Just wanted to say thanks to e-Pig, and let people know that this works (at least on my machine). I have an AT&T Lumia 1020, 32gb version:

I used the cab method (Method B) as described.
For flashing, I used this tutorial http://forum.xda-developers.com/showthread.php?t=2515453. Disabling driver signing in Windows 10 is a pain, so for flashing I instead emulated Windows 7 in VirtualBox. This required using the USB passthrough feature when connecting the phone to the PC.
The ROM I used was RM875_3051.50009.1424.0003_RETAIL_eu_euro1_211_03_447991_prd_signed.ffu , which I obtained from the mr.crab site mentioned in the flashing tutorial http://www.mrcrab.net/nokia.html. So, no need for Naviform+.
Everything good so far.
 

PepperdotNet

Member
Oct 10, 2014
22
11
Fantastic, thank you!

First try using the cab file method to unbrand my ATT RM-877.

The "tools" when I install them, I don't get an i386 folder where the iutool should be. I got a zip of the i386 folder and used that. Everything I tried to do generated ERROR: 0x80070490. It was a driver issue. I tried it on a different machine, successfully unbranded an ATT 1020 and flashed it with unbranded US CV 059W473. I tried a repair of the Lumia USB drivers from Programs and Features on the original machine, tools work there now.

Question: Do you happen to have the ATT-branded cab file, in case someone wanted to reverse the process?
 
Last edited:

e-Pig

Member
Apr 24, 2010
7
9
Please, explain me this method with one Nokia Lumia 1520 AT&T ?
Thank you.
I don't have Lumia 1520. I downloaded the RM940 rom (059V5B2) and find the Platform ID is the same as Lumia 640. It's in pconf.bin located in "PLAT" partition.
Code:
NAME=P6081_ATT
PKEY=3
SWVERSION=02540.00019.14484.37000
I haven't found a way to modify this file manually. An update cab to modify this file is needed, just as Lumia 640.
Sorry for not helping.
 
Last edited:

tyler200298

Senior Member
Nov 18, 2006
121
49
Lodi
This is from RM938 (059V3K8).
Code:
NAME=P6081
PKEY=3
SWVERSION=1028.3534.9200.10517

Hello, thanks
so this is config.pcn code from a no brand lumia 1520.
i'll try to modify one inside the phone

---------- Post added at 06:46 PM ---------- Previous post was at 06:38 PM ----------

This is from RM938 (059V3K8).
Code:
NAME=P6081
PKEY=3
SWVERSION=1028.3534.9200.10517

hello, can you zip this file and upload? so i can see complete hex
 
Last edited:

e-Pig

Member
Apr 24, 2010
7
9
Hello, thanks
so this is config.pcn code from a no brand lumia 1520.
i'll try to modify one inside the phone

---------- Post added at 06:46 PM ---------- Previous post was at 06:38 PM ----------



hello, can you zip this file and upload? so i can see complete hex

Of course.

From here I find the Platform ID update cab of ATT 1520. A non-ATT 1520 is still needed to find the cab to debrand.
 

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idlirp

New member
Jun 24, 2015
1
0
ATT L925

Hello, will it be possible to de-brand a AT&T Lumia 925 RM-893 using method B? Where can i find the cab file?
Mine is sim unlocked.
Thank you in advance.
 

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  • 8
    Finally de-brand AT&T Lumia 1020 (RM-877) successfully, this method may also work on any other Lumia Windows Phone!

    Warning: This method is not fully tested, may brick your phone! Back up all data, and do not use this method to flash any incompatible ROMs!


    Method A
    1. Update your AT&T Lumia 1020 to Windows 10 mobile and interop unlock it.
    2. Change the registry value of “DataStore” to “C:\EFIESP\efi\Nokia” in “HKLM\SOFTWARE\Microsoft\MTP”.
    3. Connect the phone to PC, open “Phone\PCONF”, copy “config.pcn” to your HDD and use a HEX editor to open it.
    4. Change P5217_ATT (HEX: 50 35 32 31 37 5F 41 54 54) to P5217 (HEX: 50 35 32 31 37 00 00 00 00) at offset 0x10, then save it.
    5. Copy modified “config.pcn” back to “Phone\PCONF” and overwrite it.
    6. Restart your phone and use flashing tools like “thor2.exe” to flash unbranded RM-875 rom!
    Method B
    1. Download the update cab (Lumia 1020 ONLY)
      Then copy the cab file to an empty folder, e.g. “c:\cab”.
    2. Download and install the tools (Thanks WojtasXda!)
    3. Connect the phone to PC, then run cmd and go to “iutool.exe” folder (default: Program Files (x86)\Windows Phone Kits\8.1\Tools\bin\i386), type
      Code:
      iutool.exe -p c:\cab -V
      The phone should restart and install updates automatically (ignore ERROR: 0x8024a110)
    4. Flash unbranded RM-875 rom!
    My AT&T Lumia 1020 is carrier unlocked, the method does not relock my phone.

    We knew AT&T changed the Platform ID (P5217_ATT) to avoid flashing RM-875 rom (P5217). The flashing tools check the platform info values of the phone and the DevicePlatformID string from the rom. Lumia 635/820 has SD card, and the device info in the registry can be changed. After the phone checking and installing updates, it is unbranded. Thus the updates can change the Platform ID info of the phone. (Thanks pankaj981 for this guide)
    I find the update cabs of an unbranded RM-876 phone (flashed RM-875 rom). Then using the iutool.exe to update AT&T RM-877 manually. After that, I flashed RM-877 with RM-875 rom successfully (Method B). Finally, I find “config.pcn” contains Platform ID. Thus for an interop unlocked phone, Method A may be easier.

    Post here if you have any questions!
    1
    Hello, thanks
    so this is config.pcn code from a no brand lumia 1520.
    i'll try to modify one inside the phone

    ---------- Post added at 06:46 PM ---------- Previous post was at 06:38 PM ----------



    hello, can you zip this file and upload? so i can see complete hex

    Of course.

    From here I find the Platform ID update cab of ATT 1520. A non-ATT 1520 is still needed to find the cab to debrand.