[Guide] De-branding AT&T Nokia Lumia 635/**820**

[pankaj981]

As far I've seen, this trick only works if you're trying to change firmware to the same variant, e.g. RM-1073 to another RM-1073. Secondly it'll only find the update if your original ROM is on a lower version than the one you intend to flash.

Edit: Try the variant as RM-1073_1011 and carrier as 000-22

 

[Fernando Cabrera]

AT&T is RM-975_1035, try it.



Are you trying to go back to AT&T firmware?

Its lumia 820 rm-824, no 635.

 

[Xanthurum]

As far I've seen, this trick only works if you're trying to change firmware to the same variant, e.g. RM-1073 to another RM-1073. Secondly it'll only find the update if your original ROM is on a lower version than the one you intend to flash.

Edit: Try the variant as RM-1073_1011 and carrier as 000-22

Hi dude!

OK, I'll try those variants...
Changing the RM-... variant DID work with the 635 from 975 to 974.

THX

 

[Xanthurum]

OK, tried your variants, no success, phone up to date...

THX anyway.

 

[pankaj981]

Its lumia 820 rm-824, no 635.

Try RM-824_lta_lta1_215 and CV as 000-CO

 

[Fernando Cabrera]

Try RM-824_lta_lta1_215 and CV as 000-CO

I already could do it, and I have denim. But what I can not change the rom, on the subject explains that you can change the ROM 635 but not the 820, so far I can not go for FFU error.

Sorry for my bad english.

 

[sucusss]

I manually flashed the T-Mobile ffu (059V6W5) - I made sure not to have any type of data or wifi connection so the update would not download until I performed the registry trick. Once I completed the registry trick (switched back to ATT-US and RM-975_1005), I checked for updates, and let it install. Upon rebooting the phone is still on T-Mobile firmware...

So you originally have an ATT 635, and then converted it to a T-Mobile 635, and now you're trying to go back to ATT?
Why are you trying to go back?

 

[k7evolution]

Hello!! We have the denim 8.10.15137.148
I can do this tutorial with this Os ????

 

[Mark F24]

I have an AT&T GoPhone 635, I followed this procedure and it was a success. I upgraded to w10m 10536.1004. I wanted to upgrade to the next w10m release and to do so the phone must be restored to w8.1, Windows Device Recovery Tool reads device but fails when the flash starts.

Reading through this thread I tried to go back to edit the registry as some suggested that changing to ATT US RM-975_1035 or 1005 may help, but at step 12 in the OP where you

12) Scroll down under "Modding selected app", select "Select the XAP" >> Phone >> sd card >> Documents >> Select "CustomPFD_0003.xap" >> Apply XAP >> Wait till you see popup "Operation completed!...." >> Done >> Close app

my phone fails. I cannot apply the XAP so if I remember correctly that is where the registry access is made. Any Ideas?

 

[pankaj981]

You will have to use Nokia Product Support Tool to flash back to the stock ROM. Before exploring that, check if Lumia Software Recovery works since it worked for one of our forum members.

 

[phil2991]

So you originally have an ATT 635, and then converted it to a T-Mobile 635, and now you're trying to go back to ATT?
Why are you trying to go back?

I am trying to go back because I would like to be able to use the Windows Device Recovery Tool again since I gave the phone to my son (just in case he ever needs a quick restore).

 

[Fernando Cabrera]

I already could do it, and I have denim. But what I can not change the rom, on the subject explains that you can change the ROM 635 but not the 820, so far I can not go for FFU error.

Sorry for my bad english.

Help

 

[pankaj981]

Help

I apologize but I am having a hard time understanding the request.

This is what I am assuming you are looking for...you have an AT&T branded Lumia 820 running the Cyan firmware that you wish to unbrand?

 

[5700xm]

Hey everybody!

Yesterday I tried to debrand my 640 LTE ATT GoPhone. (reset protection OFF)

RM-1073_1044 -> RM-1072_1052
ATT... -> 000-AT

Unfortunatly it didn't work with that trick! (on the 635 it did)
All steps in the procedure work except the last on: searching for updates...
Phone respondes with "up to date".

But I will continue watching this in the future. Maybe someone else got lucky on debranding the 640 and will share his knowledge/steps.

By the way: I'm wondering if it would be possible to just turn off that ATT logo at bootup with this handy registry editor from the tutorial since the phone working properly here in Austria on all GSM-bands... (after unlocking). Uninstalling the ATT stuff manually isn't really a lot of work so I could live with that.
Any ideas?

Cheers

Argentina CV ROM updated recently.
Product Code : 059X227
build 15184.36002 when at&t current is .36000

 

[PepperdotNet]

I have a final step to the original procedure. Only do this after you have done a successful unbrand. Use THOR2 (which is conveniently included with the Microsoft Device Recovery tool) to change the product code to match what you did in the registry. In the case of the NAM 4R CV 635 (which is the RM-975_1043 in the example) the product code is 059W4X2. Procedure below:
[INFO]Navigate to the folder where thor2.exe exists i.e. C:\Program Files (x86)\Microsoft Care Suite\Windows Device Recovery Tool and run this command with the phone plugged to USB.
thor2 -mode uefiflash -ffufile "[name of firmware file previously downloaded].ffu" -productcodeupdate 059W4X2 -skip_flash[/INFO]The -skip_flash flag prevents it from actually flashing the rom to the phone so you don't lose any data.

What this accomplishes is that you can now use the WDRT and it will recognize the phone as the new product code in case you want to use that tool to recover it in the future.
[NOTE]I have verified that this procedure works on RM-877*, RM-975 and RM-915, and doesn't on RM-820. Your mileage may vary.
*the product code change, not the unbranding[/NOTE]One more really final step for completeness, plug the phone to Nokia Care Suite and print a replacement IMEI/product code/etc barcode sticker. I'll leave that to the diligent to discover.

Thanks to anaheiim for pointing me in the right direction to discover how to do this.

 

[PepperdotNet]

So you originally have an ATT 635, and then converted it to a T-Mobile 635, and now you're trying to go back to ATT?
Why are you trying to go back?

I am trying to go back because I would like to be able to use the Windows Device Recovery Tool again since I gave the phone to my son (just in case he ever needs a quick restore).

Alternative method for being able to use WDRT: see my post just above this one.

 

[pankaj981]

I have a final step to the original procedure. Only do this after....
....Thanks to anaheiim for pointing me in the right direction to discover how to do this.

Great resource, thanks! I am adding it to the first post so its more useful.

 

[Juan Rivero]

Hi everyone. I have a question. I made the steps of the guide "Installing WP 8.1 Update 2 on Lumia Devices**" is there some problem if i do this process?

 

[pankaj981]

Hi everyone. I have a question. I made the steps of the guide "Installing WP 8.1 Update 2 on Lumia Devices**" is there some problem if i do this process?

Nope there is absolutely no problem. You can do that process after the debranding, though debranding is optional for Update 2

 

[PepperdotNet]

Hey, I just noticed that either the latest revision of WDRT changed the -skipflash to -skip_flash -- or more likely, I mistyped it when I wrote up the instructions.