Develop Bugs

[Q] At&t to T-Mobile

Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!

bradhoschar said:
Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!
Click to expand...
Click to collapse
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.

Okaham said:
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.
Click to expand...
Click to collapse
You got that right.
:thumbup:
Sent while sleeping in chair.

Okaham said:
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.
Click to expand...
Click to collapse
Wrong. Flashing an rom meant for the AT&T variant of the S3 on a T-Mobile variant S3 and vice versa will not brick the device. APN setting may get messed up and you have to enter them manually but it will not brick the device. Flashing a ROM for the international S3 on a U.S. variant of the S3 and vice versa will brick the device.
I wouldn't recommend flashing modems between the variants of S3s, that may or may not brick the device but wouldn't try it.
|When Emotion Goes up, Logic Goes Down|
---------- Post added at 03:40 PM ---------- Previous post was at 03:36 PM ----------
bradhoschar said:
Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!
Click to expand...
Click to collapse
If you want to unlock the S3 (you must be stock to do this, stocked rooted may work, but I'm not sure):
Just dial the following keys *#197328640#
Main Menu
[1] UMTS
[1] Debug Screen
[8] Phone Control
[6] Network Lock
Options [3]Perso SHA256 OFF
(after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in
[6] Network Lock then choose
[4] NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone
|When Emotion Goes up, Logic Goes Down|

Hello.
If you have signal then why are you trying to use the code? It is unlocked already!
im not an expert but this is what i know from reading a lot:
1.- I installed a t-mobile (t999) rom modified to work in a att s3 (i747), i think you can flash a any rom from the t999 section (i am not sure about this)
2.- Do NOT try to install a modem from t-mobile or you will hard brick your phone.
3.- Thats a good idea, do it and let me know if it works.
I used this files to convert an i747 to a t999 http://forum.xda-developers.com/showthread.php?t=1771021&page=25 (read from post #246) so now i use customs roms for the t999 i did it because where i live do not have good signal, was stuck at edge and with those files now i have 3g signal.
Btw, i am in the $30 prepaid t mo plan.

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re: Hmm
xmanberserker said:
Hello.
If you have signal then why are you trying to use the code? It is unlocked already!
im not an expert but this is what i know from reading a lot:
1.- I installed a t-mobile (t999) rom modified to work in a att s3 (i747), i think you can flash a any rom from the t999 section (i am not sure about this)
2.- Do NOT try to install a modem from t-mobile or you will hard brick your phone.
3.- Thats a good idea, do it and let me know if it works.
I used this files to convert an i747 to a t999 http://forum.xda-developers.com/show...771021&page=25 (read from post #246) so now i use customs roms for the t999 i did it because where i live do not have good signal, was stuck at edge and with those files now i have 3g signal.
Btw, i am in the $30 prepaid t mo plan.
Click to expand...
Click to collapse
#1: If you have a Unlocked AT&T I747 Galaxy S3 you don't need any files to convert it to work on any T999 Tmobile roms.
#2: You can use any T999 Tmobile custom roms as long as you have an Unlocked & Rooted AT&T Galaxy S3 I747 Phone.
#3: There is no such thing as installing or flashing any files which would would change the frequency for 3G on a I747 phone.
#4: Your link is dead... LOL

#4: Your link is dead... LOL[/QUOTE]
http://forum.xda-developers.com/showthread.php?t=1771021&page=25 Fixed

Misterjunky said:
#1: If you have a Unlocked AT&T I747 Galaxy S3 you don't need any files to convert it to work on any T999 Tmobile roms.
#2: You can use any T999 Tmobile custom roms as long as you have an Unlocked & Rooted AT&T Galaxy S3 I747 Phone.
#3: There is no such thing as installing or flashing any files which would would change the frequency for 3G on a I747 phone.
#4: Your link is dead... LOL
Click to expand...
Click to collapse
That is not true. Before following these instructions ( http://forum.xda-developers.com/showthread.php?t=1771021&page=25 ) I could NOT install any t-mo rom as CWM verifies the make/model before installing the rom.
Hence, me having the 'installation cannot continue' build.prop=d2att.
So, now AFTER flashing the 4 files, I was able to install 3 different T-Mobile ROMS. XTREMEPERIA ( http://forum.xda-developers.com/showthread.php?t=2199018 ) was the only one that is giving me 4G. I know, I know, its all in the APN settings, but this is the only one that gave me truly 4G speeds with a T-Mo sim.

re: 3G/4G
bradhoschar said:
That is not true. Before following these instructions ( http://forum.xda-developers.com/showthread.php?t=1771021&page=25 ) I could NOT install any t-mo rom as CWM verifies the make/model before installing the rom.
Hence, me having the 'installation cannot continue' build.prop=d2att.
So, now AFTER flashing the 4 files, I was able to install 3 different T-Mobile ROMS. XTREMEPERIA ( http://forum.xda-developers.com/showthread.php?t=2199018 ) was the only one that is giving me 4G. I know, I know, its all in the APN settings, but this is the only one that gave me truly 4G speeds with a T-Mo sim.
Click to expand...
Click to collapse
You are right, clockworkmod (Rom Manager) does verify, however if you select
and flash the Tmobile T999 recovery image when flashing clockworkmod recovery
all is fine.
Another thing, if you have a unlocked i747 and flash any Tmobile cwm zip file rom as
soon as it reboots and you check the network in the phones settings it will display
"T-Mobile US" and will work properly without the need of any other files or conversions.
However the Unlocked I747 will never work with Tmobile's 3G or 4G networks.

Misterjunky said:
You are right, clockworkmod (Rom Manager) does verify, however if you select
and flash the Tmobile T999 recovery image when flashing clockworkmod recovery
all is fine.
Another thing, if you have a unlocked i747 and flash any Tmobile cwm zip file rom as
soon as it reboots and you check the network in the phones settings it will display
"T-Mobile US" and will work properly without the need of any other files or conversions.
However the Unlocked I747 will never work with Tmobile's 3G or 4G networks.
Click to expand...
Click to collapse
Ahh...good tip about CWM
I currently have 4g on my unlocked S3 from at&t currently on T-Mobile.
And, when I was on stock, I had 3g

re: Tmobile Network.
bradhoschar said:
Ahh...good tip about CWM
I currently have 4g on my unlocked S3 from at&t currently on T-Mobile.
And, when I was on stock, I had 3g
Click to expand...
Click to collapse
Yes but when you were on stock you were on the AT&T network not Tmobile.

Misterjunky said:
Yes but when you were on stock you were on the AT&T network not Tmobile.
Click to expand...
Click to collapse
No, that is incorrect. With the 4 files I flashed, I was on T-Mobile network. It was a T-Mobile ROM, T-Mobile sim, and T-Mobile radio.

bradhoschar said:
No, that is incorrect. With the 4 files I flashed, I was on T-Mobile network. It was a T-Mobile ROM, T-Mobile sim, and T-Mobile radio.
Click to expand...
Click to collapse
Quit saying you are using a T-Mobile radio before you help someone brick their phone. The radio files are NOT interchangeable between ANY of the US variants!

EtherealRemnant said:
Quit saying you are using a T-Mobile radio before you help someone brick their phone. The radio files are NOT interchangeable between ANY of the US variants!
Click to expand...
Click to collapse
Oh, my bad. I thought 'modem' and 'radio' were the same thing.
THEY ARE!!!!
Notice in the picture how under the 'phone' tab, it says MODEM.
Yes, I flashed all 4, and now have a t-mobile setup on an at&t s3.

bradhoschar said:
Oh, my bad. I thought 'modem' and 'radio' were the same thing.
THEY ARE!!!!
Notice in the picture how under the 'phone' tab, it says MODEM.
Yes, I flashed all 4, and now have a t-mobile setup on an at&t s3.
Click to expand...
Click to collapse
You need to specify that you are using an engineering image that T-Mobile used on the 747 before the T-999 was available to test the device. In general if you flash a T-Mobile radio image to a 747, you risk losing calls and data at minimum and a hard brick at worst. It is imperative to make sure to point out that it only works with THAT engineering set.

EtherealRemnant said:
You need to specify that you are using an engineering image that T-Mobile used on the 747 before the T-999 was available to test the device. In general if you flash a T-Mobile radio image to a 747, you risk losing calls and data at minimum and a hard brick at worst. It is imperative to make sure to point out that it only works with THAT engineering set.
Click to expand...
Click to collapse
Ahh...gotcha. Thats what it states in THAT OP, I just thought that once that build was on the phone, from that point on, any T-Mo anything would work. I did have the watermark on my wallpaper, but everything else said 't-mobile'.
But, yes in general, if you flash TMO onto AT&T, there be dragons.
Thanks all, and happy flashing!

Even with that configuration, the only thing T-Mobile you can flash is recovery and custom ROMs. A T-999 baseband or boot loader could very well cause a brick. Its a dangerous hack because it has everyone confused. For all intents and purposes, it is 747 software with T-Mobile's AWS capability. In fact it doesn't even seem to have DC-HSPA, only HSPA+ (21mbps versus 42). It has the benefit of supporting T-Mo LTE though.

Awesome
EtherealRemnant said:
Even with that configuration, the only thing T-Mobile you can flash is recovery and custom ROMs. A T-999 baseband or boot loader could very well cause a brick. Its a dangerous hack because it has everyone confused. For all intents and purposes, it is 747 software with T-Mobile's AWS capability. In fact it doesn't even seem to have DC-HSPA, only HSPA+ (21mbps versus 42). It has the benefit of supporting T-Mo LTE though.
Click to expand...
Click to collapse
Very good to know! Thanks for the info. Perhaps when T-Mo refarms their LTE, I won't have to do much to this beastly phone!
Thanks all!
:good:

bradhoschar said:
Very good to know! Thanks for the info. Perhaps when T-Mo refarms their LTE, I won't have to do much to this beastly phone!
Thanks all!
:good:
Click to expand...
Click to collapse
It doesn't make sense for T-Mobile to refarm their LTE. The 1700 AWS band is the most efficient spectrum they currently own and the AWS spectrum is going to be the most compatible across LTE networks. T-Mobile has pretty much no chance of ever getting the 700MHz that at&t and Verizon are using.

Using t999 on at&t

Well, just moved to washingron, and t-mobile has no coverage within 10 miles of where I am at, but at&t has full 4g here. Got the at&t sim, on the go-phone plan, modified the apn and get data now. However, I keep getting warnings that my sim card is bad by several t-mobile functions. Can I flash an att rom to it, and do I need to avoid the att modems, or are they also ok to flash on the att network?
Sent from my SGH-T999 using xda app-developers app

5ft24 said:
Well, just moved to washingron, and t-mobile has no coverage within 10 miles of where I am at, but at&t has full 4g here. Got the at&t sim, on the go-phone plan, modified the apn and get data now. However, I keep getting warnings that my sim card is bad by several t-mobile functions. Can I flash an att rom to it, and do I need to avoid the att modems, or are they also ok to flash on the att network?
Sent from my SGH-T999 using xda app-developers app
Click to expand...
Click to collapse
No. You can't do that.

re: at&t - tmobile
5ft24 said:
Well, just moved to washingron, and t-mobile has no coverage within 10 miles of where I am at, but at&t has full 4g here. Got the at&t sim, on the go-phone plan, modified the apn and get data now. However, I keep getting warnings that my sim card is bad by several t-mobile functions. Can I flash an att rom to it, and do I need to avoid the att modems, or are they also ok to flash on the att network?
Sent from my SGH-T999 using xda app-developers app
Click to expand...
Click to collapse
First of all, don't flash any modems.
My phone is an AT&T Unlocked i747 Galaxy S3 and I no longer have AT&T service, but instead I chose Tmobile.
I now have a tmobile sim and have been flashing Tmobile roms ever since I changed my carrier to tmobile.
Everything works fine as long as I do NOT flash any Tmobile Modems.
None of the Tmobile or AT&T custom roms contain the modem image.
All of this also holds true when coming from Tmobile sim and going with AT&T sim.
If your phone is not unlocked I would suggest that you unlock it for best results.

Misterjunky said:
First of all, don't flash any modems.
My phone is an AT&T Unlocked i747 Galaxy S3 and I no longer have AT&T service, but instead I chose Tmobile.
I now have a tmobile sim and have been flashing Tmobile roms ever since I changed my carrier to tmobile.
Everything works fine as long as I do NOT flash any Tmobile Modems.
None of the Tmobile or AT&T custom roms contain the modem image.
All of this also holds true when coming from Tmobile sim and going with AT&T sim.
If your phone is not unlocked I would suggest that you unlock it for best results.
Click to expand...
Click to collapse
What about kernels? Which T-Mobile ones can we flash onto an AT&T S3? I'm doing what you are. AT&T S3 on T-Mobile.

re: kernels
popi09 said:
What about kernels? Which T-Mobile ones can we flash onto an AT&T S3? I'm doing what you are. AT&T S3 on T-Mobile.
Click to expand...
Click to collapse
If you have a tmobile sim chip then flash tmobile kernel.
If you have a AT&T sim chip then flash AT&T kernel.
But if I were you I would stay with stock kernels which all the custom Jellybean 4.1.1 roms already come with.
So if you flash a Tmobile custom rom, it will come with a tmobile kernel.
If flashing a AT&T custom rom it will come with the stock AT&T kernel.
Good luck!

Misterjunky said:
If you have a tmobile sim chip then flash tmobile kernel.
If you have a AT&T sim chip then flash AT&T kernel.
But if I were you I would stay with stock kernels which all the custom Jellybean 4.1.1 roms already come with.
So if you flash a Tmobile custom rom, it will come with a tmobile kernel.
If flashing a AT&T custom rom it will come with the stock AT&T kernel.
Good luck!
Click to expand...
Click to collapse
Awesome! I have a T-Mobile Sim in my ATT s3. I'm running universe s4 ROM. So I wouldn't have to flash a kernel when flashing TW ROMs from tmo?

re: kernels
popi09 said:
Awesome! I have a T-Mobile Sim in my ATT s3. I'm running universe s4 ROM. So I wouldn't have to flash a kernel when flashing TW ROMs from tmo?
Click to expand...
Click to collapse
You never have to flash a kernel regardless of which rom you flash.
All roms come with kernels, all the kernels you see here in XDA which are separate
downloads are custom kernels unless they are specified as being stock.
Custom kernels might be OK for experimenting for those people who want to
over clock or under volt their phones. In my opinion it's a waste of time and
cause more problems or issues than whatever advantages they may have.
(in my personal experience custom kernels have no real advantages at all)

tmobile phone att sim cut down
ok i have a unlocked rooted t-mobile phone, a att go phone sim, cut down to size and can make calls , and even send pictures but some small setting is stoping me from geting data to work ,
i have nothing i am worried about backing up so i can install any rom that may work i just need some direction help please i keep reading thru. all the apn setting and cant find what i may be doing wrong

Hotspot

Hello all, I recently switched over from AT&T to TMO with an unlocked AT&T GS4. My cell says that I have an invalid sim card when I try to use it as a hotspot. I called TMO and they told me not all TMO features will work on a ATT phone thats unlocked. Any walk arounds??

tony1208 said:
Hello all, I recently switched over from AT&T to TMO with an unlocked AT&T GS4. My cell says that I have an invalid sim card when I try to use it as a hotspot. I called TMO and they told me not all TMO features will work on a ATT phone thats unlocked. Any walk arounds??
Click to expand...
Click to collapse
Flash tmobile base ROM
☞ Sent from here☜???

Cant root I am on 4.3 mj9 att
Sent from my Galaxy S4

Check the att forum, pretty sure there's info there about dual booting and flashing custom rom

Same Boat...
mrhughy said:
Check the att forum, pretty sure there's info there about dual booting and flashing custom rom
Click to expand...
Click to collapse
I have an AT&T variant (unlocked) as well and I while I cannot install a recovery without Safestrap, I do have Safestrap installed. I also called T-mobile about the Wifi Hotspot not working and they advised me that it would not work on their stock rom but I could try flashing a T-mobile version. I've tried about a dozen rom's so far but I cannot get some of them to boot at all and the ones that do, I have no working Wifi. I've also tried about 6 different AT&T kernels with these roms and so far, nothing works. I 'think' this is something to do with Safestrap but I don't know for sure.

Any way to get wifi calling on unlocked s9?

Is there any way to get wifi calling on att with an unlocked s9 from best buy? Flashing att firmware or would it be best to get the att model? Must have wifi calling for work reasons and I hate all the bloatware but might not have a choice.

at&t probably blocks it, if you don't get their version. I have an unlocked, but on T-Mobile, and it works.

I flashed the AT&T firmware on my unlocked S9 and wifi calling and video calling worked.
With the stock firmware on the unlocked S9 nether option was there

Can you point me in the direction of a download for the stock firmware for AT&T? I'm wanting to do the same as well, but feeling pretty clueless about where to obtain it. thanks!

Same here. It works for me on T-Mobile

If I flash the att firmware will I still get firmware updates?

f10a said:
Flashing att firmware or would it be best to get the att model?
Click to expand...
Click to collapse
if you flash the att firmware or buy it straight from att you will end up a device supporting the same capabilities. So it's down to your tech skills or budget.

Where can I find the latest att firmware? I did not see it on sammobile.

How to
Step 1 Go to this thread for Firmware (thanks @iBowToAndroid)
You will want to go to the link for the U firmware and find the folder with the AT&T userdata file (RB7) download the user data file and the full firmware.
Step 2 Go to this thread to get the modified version of Odin that recognizes the GS9 firmware files. (Thanks @mweinbach and Raymondf )
You will then flash the downloaded files from Step 1 in Odin, after flashing the firmware the phone will boot into recovery and you will need to wipe data and cache.

Thanks so much... that did actually help me... as a fairly tech savvy person who doesn't really get into this stuff much, the lingo I didn't know was leading me astray... I had come across that thread but didn't recognize it as anything that would help me. Thanks again! Onward to bricking my phone!

StolenVW said:
I flashed the AT&T firmware on my unlocked S9 and wifi calling and video calling worked.
With the stock firmware on the unlocked S9 nether option was there
Click to expand...
Click to collapse
Thanks for the info. A follow-up question: is it possible to flash it back to the stock unlocked firmware? The reason is that I'll need to use foreign SIM card when I travel overseas.

handydandy said:
Thanks for the info. A follow-up question: is it possible to flash it back to the stock unlocked firmware? The reason is that I'll need to use foreign SIM card when I travel overseas.
Click to expand...
Click to collapse
I have unlocked version on TMobile and wifi calling works just fine.

Do you have to flash the att firmware to the unlocked version in order to get VoLTE? I don’t care about WiFi calling, just hd calling and being able to stay on lte when making a call, rather than have it drop to HSPA during the call.

StolenVW said:
I flashed the AT&T firmware on my unlocked S9 and wifi calling and video calling worked.
With the stock firmware on the unlocked S9 nether option was there
Click to expand...
Click to collapse
Probably wont last. Unless att has an imei number from an wifi calling att phone on that account it will eventually go away.

Thor2j said:
Probably wont last. Unless att has an imei number from an wifi calling att phone on that account it will eventually go away.
Click to expand...
Click to collapse
I have unlocked S9 - I have wifi calling on tmobile and att. It's in the phone app settings. Not the device settings.

Wifi Calling
Here's a screenshot

sd_N said:
I have unlocked S9 - I have wifi calling on tmobile and att. It's in the phone app settings. Not the device settings.
Click to expand...
Click to collapse
I understand, but unless att has changed its policies in the last month, if u do not have an imei number on that account that is an att phone with wifi calling it will turn itself off as soon as your phone is interrogated by the network. Theres 100 threads on it , applies to unlocked s8, s7, etc...
Toggle is there because of firmware, not because it works.

Thor2j said:
I understand, but unless att has changed its policies in the last month, if u do not have an imei number on that account that is an att phone with wifi calling it will turn itself off as soon as your phone is interrogated by the network. Theres 100 threads on it , applies to unlocked s8, s7, etc...
Toggle is there because of firmware, not because it works.
Click to expand...
Click to collapse
That's the way it's supposed to work.

Any help/guidance for me??
I have tried a few times to use the March 2018 RB7 files with the ATT user data to get my phone to ATT stock - primarily for the Enhanced LTE (data and voice at the same time), as well as Wifi Calling. I can't get that version to load. I did get a more recent version to load (RK1) - and maybe that is the issue. Just wondering if there is a newer set of files and what specifically I should use (AP,BL... UserData) to get the phone fully set to AT&T. I now have the wifi calling option, just can't get it enabled. Any help is appreciated.

salevine said:
I have tried a few times to use the March 2018 RB7 files with the ATT user data to get my phone to ATT stock - primarily for the Enhanced LTE (data and voice at the same time), as well as Wifi Calling. I can't get that version to load. I did get a more recent version to load (RK1) - and maybe that is the issue. Just wondering if there is a newer set of files and what specifically I should use (AP,BL... UserData) to get the phone fully set to AT&T. I now have the wifi calling option, just can't get it enabled. Any help is appreciated.
Click to expand...
Click to collapse
When you try to enable it do any of the AT&T Wifi calling configuration screens pop up?

Can all USA Galaxy S9 models be flashed to each other's firmware?

I've read that the Galaxy S9 hardware is identical for all carriers in the USA.
If I bought a factory unlocked Galaxy S9 can I flash it to the carrier I am using (Verizon, Sprint, T-Mobile, AT&T) to enable carrier specific software and features? Can I flash it back to the unlocked firmware?
I already see a thread about flashing the unlocked firmware to carrier models so I am assuming there are no issues there.
Can one carrier model be flashed to another carrier model?

No, bootloaders are different, with the S7 there was an unbranded U firmware that was compatible with most of them, unlocked firmware will be that one for the S9, but no you cannot just flash different device firmwares to the wrong model

I was able to flash the ATT rom onto my Verizon S9. I got a VZ s9 from work but I'm on ATT. For the most part it's worked great, I had done the same thing previously with a Galaxy S7. I say for the most part b/c I am on here tonight to post a question myself about the fact that I'm getting a delay with MMS messages. I imagine it has something to do with the APNs I have setup, but I can't seem to figure it out.

toronado13 said:
I was able to flash the ATT rom onto my Verizon S9. I got a VZ s9 from work but I'm on ATT. For the most part it's worked great, I had done the same thing previously with a Galaxy S7. I say for the most part b/c I am on here tonight to post a question myself about the fact that I'm getting a delay with MMS messages. I imagine it has something to do with the APNs I have setup, but I can't seem to figure it out.
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Click to collapse
Did you have to flash to the U1 software first?

I do think that is what I ended up doing... tried to go directly first and it kept failing. Got fed up and decided to just try and put the bone stock rom on it, and that went on really easily.... so after using it like that a few days I tried to drop the ATT rom on it and it worked without issue.

SEALBoy said:
I've read that the Galaxy S9 hardware is identical for all carriers in the USA.
If I bought a factory unlocked Galaxy S9 can I flash it to the carrier I am using (Verizon, Sprint, T-Mobile, AT&T) to enable carrier specific software and features? Can I flash it back to the unlocked firmware?
I already see a thread about flashing the unlocked firmware to carrier models so I am assuming there are no issues there.
Can one carrier model be flashed to another carrier model?
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Click to collapse
Yes, but you need to go to the u1 firmware 1st then to the other carrier firmware. Also make sure you avoid the newer firmwares with the new bootloader, as the unlocked model and certain carrier models don't have the new bootloader.

*Detection* said:
No, bootloaders are different, with the S7 there was an unbranded U firmware that was compatible with most of them, unlocked firmware will be that one for the S9, but no you cannot just flash different device firmwares to the wrong model
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lolol
yes u can.. u can flash between U and U1 firmwares no problem..
normally ud b correct tho but since s8/s8+ it has been ok.. just cant flash 9600 or 9650 to a U or U1 device

elliwigy said:
lolol
yes u can.. u can flash between U and U1 firmwares no problem..
normally ud b correct tho but since s8/s8+ it has been ok.. just cant flash 9600 or 9650 to a U or U1 device
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Click to collapse
That'll be why I still thought that then, coming straight from the S7 > S9
Had many members flashing the wrong firmwares thinking they could do that and bricking their S7s / wondering why ODIN failed

*Detection* said:
That'll be why I still thought that then, coming straight from the S7 > S9
Had many members flashing the wrong firmwares thinking they could do that and bricking their S7s / wondering why ODIN failed
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Click to collapse
I tried downloading vzw firmware G960USQS3ARI6 to my unlocked sprint s9 and still not vzw flashed. want to do this so can have voice over LTE. Any other steps im missing? flash went through but still sprint

As soon as Firmware ver. 3 came out for the G960U1, I was able to flash it to my Sprint G960U and finally have VoLTE, WiFi calling and stable LTE for MetroPCS. Used samkey to unlock it from Sprint. My phone is actually performing much faster without all of Sprint's bloatware hogging my RAM and storage space. I can confirm that OTA updates still work the same...I received September's security patch (current) with no problems. Device is still official status and Knox hasn't been tripped.
A lot of people think you can just flash the carrier firmware of your choice and boom, it works...I had the same thought process....that's not the case. You have to make sure that there is a matching firmware version for the carrier you want to flash to, as well as make sure the G960U1 firmware version (the unlocked version of the S9's software you have to flash first before even carrier flashing) is the same version of what is installed on your phone now. It's easy ya'll......just READ lol.
I'm in love with my phone again thanks to XDA. ?
HAPPY FLASHING!

nickosarus2008 said:
As soon as Firmware ver. 3 came out for the G960U1, I was able to flash it to my Sprint G960U and finally have VoLTE, WiFi calling and stable LTE for MetroPCS. Used samkey to unlock it from Sprint. My phone is actually performing much faster without all of Sprint's bloatware hogging my RAM and storage space. I can confirm that OTA updates still work the same...I received September's security patch (current) with no problems. Device is still official status and Knox hasn't been tripped.
A lot of people think you can just flash the carrier firmware of your choice and boom, it works...I had the same thought process....that's not the case. You have to make sure that there is a matching firmware version for the carrier you want to flash to, as well as make sure the G960U1 firmware version (the unlocked version of the S9's software you have to flash first before even carrier flashing) is the same version of what is installed on your phone now. It's easy ya'll......just READ lol.
I'm in love with my phone again thanks to XDA.
HAPPY FLASHING!
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Click to collapse
Hi, I got one unlocked G960U1(G960U1UES3ARI1) and downloaded new fireware(G960U1UES3ARI1-SPR) from sammobile, but after flashed SPR ROM successfully, the info on the phone still shows XAA, anything I missed here? Thanks!

Curtis2018 said:
Hi, I got one unlocked G960U1(G960U1UES3ARI1) and downloaded new fireware(G960U1UES3ARI1-SPR) from sammobile, but after flashed SPR ROM successfully, the info on the phone still shows XAA, anything I missed here? Thanks!
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Click to collapse
Well first off, you have the unlocked phone. I don't. My G960U is originally from Sprint, so I'm not sure about carrier flashing regarding the G960U1. I thought it was supposed to provision itself after you put the sim in, and the associated carrier apps will download since it's the unlocked model...but I may be wrong...

SEALBoy said:
I've read that the Galaxy S9 hardware is identical for all carriers in the USA.
If I bought a factory unlocked Galaxy S9 can I flash it to the carrier I am using (Verizon, Sprint, T-Mobile, AT&T) to enable carrier specific software and features? Can I flash it back to the unlocked firmware?
I already see a thread about flashing the unlocked firmware to carrier models so I am assuming there are no issues there.
Can one carrier model be flashed to another carrier model?
Click to expand...
Click to collapse
I know so many people have already answered your question from some saying No to others saying Yes but you need to Install U1 first and Bla Bla Bla.
I want to give you one specific answer: With S9 you can any Carriers firmware you wish or even Unlocked phone's firmware. You will never have any issue. And you don't ever need to flash U1 or something else before changing carrier firmware you can Flash from ATT S9 firmware to VZW S9 firmware without any issue. You can also flash from U to U1 which is from Carrier specific to Unbranded/Unlocked but only hiccup is original Odin will give you SHA-256 error, which is normal because you are flashing U1 firm to U device or vice versa. This error can easily be resolved by used Patched odin that disabled SHA-256 check. And trust me you will never have any issue.
You will never want to do this but I have gone as far as mix-matching U and U1 firmware together as well. Like flashing AP, BL and CP of U device but flashing CSC of U1 device. and it still works.

hey there, a little late to the party, having trouble with going from a Verizon to a Sprint, even by way of U1. I can't get any of them to work. And I've been told I have to go from VZW to U1 before I went to Sprint. Is that not the case? I'm having a hell of a time getting anything to flash, everything fails.
---------- Post added at 03:08 AM ---------- Previous post was at 02:57 AM ----------
ret4425 said:
hey there, a little late to the party, having trouble with going from a Verizon to a Sprint, even by way of U1. I can't get any of them to work. And I've been told I have to go from VZW to U1 before I went to Sprint. Is that not the case? I'm having a hell of a time getting anything to flash, everything fails.
Click to expand...
Click to collapse
well, I tried to load the Sprint image from the VZW, no dice. It said it passed, but upon reboot loaded up the old Big Red (even with the Sprint SIM in it).
Anyone have any ideas? This is driving me insane....