De-brand your AT&T Lumia 640 LTE.

[dlalonde]

Yes they will..you don't need to worry about them. As soon as the files have been transferred follow the instructions and flash the phone. You should be all set...

Do I need other files if I ever want to go back to AT&T or should I use the same files or just change the product code like in the tutorial and flash the ROM from WDRT? Do those CAB files come from a 640 from T-Mobile or elsewhere? Would they work on another carrier (say MetroPCS for example)?

 

[pankaj981]

1) you'll never be able to go back to the AT&T ROM

2) I don't know where those cab files come from but you I'll definitely be able to flash to any non-AT&T ROM after this process

3) you have to be careful about what ROM you're flashing. Most RM-1072 ROMs would be safe to flash

 

[dlalonde]

1) you'll never be able to go back to the AT&T ROM

2) I don't know where those cab files come from but you I'll definitely be able to flash to any non-AT&T ROM after this process

3) you have to be careful about what ROM you're flashing. Most RM-1072 ROMs would be safe to flash

1) Oh, so it's a permanent thing then. That's odd. I thought the updated files (the CAB) were just updating the ROM itself.

2) Gotcha

3) Yeah I would only flash those that come from the WDRT

1) you'll never be able to go back to the AT&T ROM

2) I don't know where those cab files come from but you I'll definitely be able to flash to any non-AT&T ROM after this process

3) you have to be careful about what ROM you're flashing. Most RM-1072 ROMs would be safe to flash

By the way thank you for your support. I know I had 1 000 000 questions but you answered me with patience. I do apologize too because I wanted to get my LTE working but got worried about what I was putting in my phone.

Anyhow, again, thank you! I really appreciate it.

 

[fishsniffer2]

would you follow the same procedure to change from a Metro PCS Lumia 640 to a T-mobile lumia 640?
and if so does the Metro PCS phone need to be SIM unlocked to flash to Tmobile ROM? Thanks!

 

[dlalonde]

would you follow the same procedure to change from a Metro PCS Lumia 640 to a T-mobile lumia 640?
and if so does the Metro PCS phone need to be SIM unlocked to flash to Tmobile ROM? Thanks!

No. That procedure is because AT&T has its hand deeply in the phone

I've done it for MetroPCS to T-Mobile in the past following this: https://stebet.net/how-to-install-a-country-variant-firmware-with-the-windows-phone-recovery-tools/

It's quite easy to follow

 

[Daryth]

If anyone wants to debrand their AT&T Lumia 640, I've posted the guide on how to do it here on xda-dev.

De-Brand [ATT] Lumia 640 LTE | Windows Phone 8 Development and Hacking

Have a good day and happy flashing.

If I have a new (never on network) AT&T 640 and AT&T tells me it's already ulockes and I just need to wait for the unlock code in an email....

Will flashing a T-Mobile firmware get me around this? I don't understand if AT&T is saying the iemi is unlocked why they can't just give me the code to use a different sim card

 

[ScrubbyXD]

The AT&T person obviously lied to confuse you or was confused. We are dealing with two terms here:

1) Blocked - Refers to a carrier listing the phone (and thus it's IMEI) as stolen or unpaid. This is also refered to as "Blacklisting". This status prevents you from normally acquiring an unlock code or using it on another carriers network even if unlocked.

2) Locked - Many phones (but not all) come with a firmware "lock" to prevent a phone from being used on a competitor's network. To allow use on another network (if compatible) you would need an "unlock" code. This code is generated using the phone's IMEI number but otherwise the IMEI has nothing to do with the lock.

If I have a new (never on network) AT&T 640 and AT&T tells me it's already unlocked and I just need to wait for the unlock code in an email....

Out of the Box the phone IS carrier locked to AT&T. Using the phone with another networks's sim will require an unlock code. You can acquire a free unlock code in the usual way described in this forum.

Will flashing a T-Mobile firmware get me around this? I don't understand if AT&T is saying the iemi is unlocked why they can't just give me the code to use a different sim card

Re-Branding will NOT remove the carrier lock.

 

[tpapictures]

Does anyone happen to know...
1. if either of the Argentina or Mexico CV ROM causes anything important to be disabled on this AT&T 640 if you flash them? Stuff like WiFi calling, etc?
2. also, if the two are roughly the same, why does the Argentina version end up getting a FW update and not the Mexico one? Just the particularities of each network?
3. once you get them to receive the update to 10, are they identical in software and firmare or is it eventually better to have one over the other? I've got mine unlocked and I'll flash either one but would rather not have to go through it more than once.
4. I think I saw someone getting the UK CV to get the full 10 update as well. Would there be anything wrong with flashing that RM-1072 ROM on this 1073 phone?

Thanks!

 

[ma678]

I have tried both Argentina and Mexican CV roms and ended up with AR one. Nothing important except no bloatware. I received w10m official update on AR rom but not tried to do that on the other one.

I remember seeing someone mention rm-1072 roms don't work on rm-1073 model.

 

[fishsniffer2]

Thank You! I was hoping to find a better step by step, I tried to follow your instructions but they are somewhat to complicated for me, lost track several times,probably a cakewalk for a guy with your knowledge but for the average Joe like me need to be spoon fed!

 

[Mark F24]

Thank You! I was hoping to find a better step by step, I tried to follow your instructions but they are somewhat to complicated for me, lost track several times,probably a cakewalk for a guy with your knowledge but for the average Joe like me need to be spoon fed!

You are using the guide at XDA Developers right? The guide in the first post also has a link to a second guide in step 10, when following the guides remember that in the examples they use %xxx% or "xxx", don't include the % or the " in the command prompt.

 

[dlalonde]

I have tried both Argentina and Mexican CV roms and ended up with AR one. Nothing important except no bloatware. I received w10m official update on AR rom but not tried to do that on the other one.

I remember seeing someone mention rm-1072 roms don't work on rm-1073 model.

Tried them both as well but couldn't get 4G to work for some reason. Works perfectly well with T-Mobile so I'll be going back to that one. My only concern lies with the firware updates. If T-Mobile has abandonned the platform, will my phone suffer from lack of firmware updates?

 

[jamssx]

As we keep hearing TMO is in the process of certifying the IMS/Wifi calling fix and once (if) that occurs then the firmware will get pushed. After that it's MS that pushes the OS updates as long as they don't touch the 'phone' functions. So you should get all the W10 updates.

 

[shikhanshu]

If anyone wants to debrand their AT&T Lumia 640, I've posted the guide on how to do it here on xda-dev.

De-Brand [ATT] Lumia 640 LTE | Windows Phone 8 Development and Hacking

Have a good day and happy flashing.

Is following steps on lumiafirmware.com not enough to make the phone non-AT&T and start getting Win10 updates from MS officially and directly?
http://www.lumiafirmware.com/info

 

[dlalonde]

Is following steps on lumiafirmware.com not enough to make the phone non-AT&T and start getting Win10 updates from MS officially and directly?
http://www.lumiafirmware.com/info

I didn't try that one! But I don't know if it de-brands AT&T phones but if it does work, you'll still have to flash a ROM that comes from a place where MS offers the updates, like Argentina or Mexico.

 

[tpapictures]

I'm completely confused by this. I must be missing something...
- 1st XDA method involves LumiaFlashTools which is no longer offered.
- You're then told to follow a different set of instructions that include "64 bit checker" which the first method doesn't mention.
- But then if you go to lumiaifrmware.com you get a whole other set of rules?

What method has worked for those of you who have done this?

Thanks!

 

[shikhanshu]

I'm completely confused by this. I must be missing something...
- 1st XDA method involves LumiaFlashTools which is no longer offered.
- You're then told to follow a different set of instructions that include "64 bit checker" which the first method doesn't mention.
- But then if you go to lumiaifrmware.com you get a whole other set of rules?

What method has worked for those of you who have done this?

Thanks!

From what I understand, the instructions on lumiafirmware.com are general instructions to put a new ROM on your Lumia.
But the extra instructions on this post are specific to AT&T Lumia 640 in order to de-brand it. I don't know why de-branding is required additionally for AT&T Lumia 640 though. Won't putting a new ROM (say the 7R CV) be sufficient to make it a non-AT&T phone and starting getting official Win10 OTA from Microsoft (along with firmware updates from Microsoft)?

 

[boonesmi]

From what I understand, the instructions on lumiafirmware.com are general instructions to put a new ROM on your Lumia.
But the extra instructions on this post are specific to AT&T Lumia 640 in order to de-brand it. I don't know why de-branding is required additionally for AT&T Lumia 640 though. Won't putting a new ROM (say the 7R CV) be sufficient to make it a non-AT&T phone and starting getting official Win10 OTA from Microsoft (along with firmware updates from Microsoft)?

yeah the xda method is required to unlock the the ATT go phone (im not talking about sim unlocking)

if you tried using the "lumiafirmware.com" directions it would error. it would error on any locked phone trying to load a rom that doesnt match the product ID (thats one of the things the xda method will do is change the phones product ID)

**edit to add**
the xda link hasn't been updated in a long time, it doesn't have the info about the importance doing a full NVI update (it was discovered later in that thread)
also several people have complained about it being confusing and having many unnecessary steps.

so some kind soul took all the info and created a new guide (he was kind enough to give credit where it was due!!)
here is a link
https://www.reddit.com/r/windowsphone/comments/4bcvgg/comprehensive_guide_to_lumia_640_unlocking/

 

[tpapictures]

so some kind soul took all the info and created a new guide (he was kind enough to give credit where it was due!!)
here is a link
https://www.reddit.com/r/windowsphone/comments/4bcvgg/comprehensive_guide_to_lumia_640_unlocking/

That's really nice but I don't typically like running bat files that people have assembled where I'm not doing every step myself. Does anyone know which published instructions are best to use if the xda one is out of date?

 

[dlalonde]

That's really nice but I don't typically like running bat files that people have assembled where I'm not doing every step myself. Does anyone know which published instructions are best to use if the xda one is out of date?

I completely understand (if you read my previous posts you'll see )

From what I can tell, the bat file is used to install the three CAB files necessary to unbranding the AT&T phone. I've done it without any BAT file using iutool that you can download from one of the posts in the XDA thread. When you run the installer, you'll see that it dates from WP7 but it works without any problems.

This is the guide I followed: Tutorial: How to De-Brand your AT&T Lumia 640 LTE & Flash another ROM | Nokiapoweruser

It's more well structured vs a forum thread. Everything worked out great and I've been using my phone with the T-Mobile ROM for the past 2 weeks already.