De-brand your AT&T Lumia 640 LTE.

[Meier538]

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

http://forum.xda-developers.com/win...ia-640-lte-t3294971/post64841455#post64841455

Have a good day and happy flashing.

 

[libra89]

This is great, and will be very helpful to some people out there, thank you for writing this up and sharing! I do wonder if it's possible to flash to another country variant that is single sim, and unlocked.

 

[Meier538]

Yes, this is for the single sim phones, RM-1072, RM - 1073. I am not sure if it would work for dual sims. this guide is based on removing atts dumb deviceplatformid block.

And sorry about the link be fragmented, I do not have enough post to post a link heh.

 

[njstol01]

So the big question- does LTE band 12 now work? I've debranded the outside ATT logo simply by adding a case, and the start splash screen is not an issue, but doing this risky procedure might be worth it to extend its LTE capability. Thanks for the effort!

 

[libra89]

So the big question- does LTE band 12 now work? I've debranded the outside ATT logo simply by adding a case, and the start splash screen is not an issue, but doing this risky procedure might be worth it to extend its LTE capability. Thanks for the effort!

It should work technically because that firmware disables it. It's different from it not being in the phone at all.

 

[ombreman]

Success! Reflashed ATT Lumia RM-1073 to RM-1072 European ROM. Cant check the LTE bands as ##3282# doesnt work in this rom.

 

[leematthews]

Thanks! Was in the same boat with an unlocked ATT and was using T-Mobile. Nice guide, pretty straightforward and easy to go through.

 

[boonesmi]

my wife and i both use the tmobile 640. on a whim i bought one of the ATT ones on blackfriday for $29 as a backup phone.

i first saw this post right after it was posted, but only today had some time to try it out

it allows you to do 3 things:
unlocks att firmware (this is different then unlocking carrier)
install firmware of your choice (i did the US tmobile)
change product ID (so if you run updates in the future it wont accidentally load AT&T)

i live in an area with band 12, and yes i verified in fieldtest that band 12 is now available

band 12 was the one feature that made using a carrier unlocked at&t phone on t-mobile something that wouldn't work for my wife. she works in a big office building and without band 12 she gets no signal.

 

[libra89]

my wife and i both use the tmobile 640. on a whim i bought one of the ATT ones on blackfriday for $29 as a backup phone.

i first saw this post right after it was posted, but only today had some time to try it out

it allows you to do 3 things:
unlocks att firmware (this is different then unlocking carrier)
install firmware of your choice (i did the US tmobile)
change product ID (so if you run updates in the future it wont accidentally load AT&T)

i live in an area with band 12, and yes i verified in fieldtest that band 12 is now available

band 12 was the one feature that made using a carrier unlocked at&t phone on t-mobile something that wouldn't work for my wife. she works in a big office building and without band 12 she gets no signal.

Your wife's story is my story at work too. I tried a phone without band 12, it was fine at home, no service at work a lot. Glad you were able to fix it.

 

[brusbrother]

Is band 12 only available/useful for tmobile service?

 

[libra89]

Is band 12 only available/useful for tmobile service?

Pretty much, yes. It provides better coverage in a number of areas around the US, especially inside buildings.

 

[charktorious]

Another success story here - so far so good with my AT&T 640, now running the TMo firmware. Only stumble I had were errors on my x64 Win10 PC with iutool:

ERROR: 0x80070490
Command failed. (HRESULT = 0x80070490)

Tried an x86 Win10 PC, fairly clean setup, and that one worked to install the cabs with iutool.

 

[boonesmi]

Is band 12 only available/useful for tmobile service?

yeah tmobile any any tmobile mvno's are the only ones that use band 12, and yeah band 12 is a low freq signal that has great building penetration and travels longer distances

 

[boonesmi]

Another success story here - so far so good with my AT&T 640, now running the TMo firmware. Only stumble I had were errors on my x64 Win10 PC with iutool:

ERROR: 0x80070490
Command failed. (HRESULT = 0x80070490)

Tried an x86 Win10 PC, fairly clean setup, and that one worked to install the cabs with iutool.

for me the iutool installed with no errors (x64 win10 pro)

 

[ScrubbyXD]

Success on my AT&T to T-Mobile. now I have a t-mobile 640 I don't necessarily need...:asleep:

 

[jpharwood]

If I install the T-Mobile rom on my unlocked AT&T 640 will I be able to enable WiFi calling?

 

[PepperdotNet]

Bought a 640 gophone at best buy this afternoon (price match Walmart $29.88 deal).

Submitted and waiting on unlock code. Successful unbranding.

 

[ScrubbyXD]

With the T-mobile firmware yes you have wifi calling, HD voice and band 12 just as if it was a phone from T-Mobile.

Be careful to not brick it.

 

[barber76]

If I install the T-Mobile rom on my unlocked AT&T 640 will I be able to enable WiFi calling?

But you must use the phone on T-Mo then.

 

[jpharwood]

That's what I suspected, just sounded too good to be true. Thanks for the help...