Develop Bugs

Proper root method for an unlocked AT&T GS3

My dad just bought a AT&T GS3 from a friend and I just finished unlocking it so he can use his T-Mobile service. We've confirmed his voice calling is working. I want to root this phone so I can flash a stock ROM that removes all the AT&T stuff. What's the proper way to root the unlocked phone now? Thanks in advance for any guidance you can provide.
PS. Any work around to get 3G vs Edge?

Look in the dev section EVERYTHING you need is in there. This question on how to root is asked so much its not even funny anymore. Oh wait I just seen your paps is on tmobile, if you want a stock rom for that you need to go to their section
Sent from my SGH-I747M using xda premium

the phone should stay unlocked through rooting and a custom rom. mine is unlocked, rooted, with aokp on it and it still can use other carrier's sim cards with no problem. about the 1700 band, there is currently no way to use it with this phone. there is a bounty thread in the general section about it.
edit: do you want a stock tmobile rom or a vanilla android rom?
sent from my I747

Thanks for the replies. I guess where I'm confused is what root method do I use? ATT since it's ATT hardware, or Tmobile since it's now unlocked and connected to TMobile? Sorry for my lack of knowledge on this.

Zameus said:
Thanks for the replies. I guess where I'm confused is what root method do I use? ATT since it's ATT hardware, or Tmobile since it's now unlocked and connected to TMobile? Sorry for my lack of knowledge on this.
Click to expand...
Click to collapse
use the att method because it's att hardware.
sent from my I747

Galaxy S4 ATT, install T-mobile Stock ROM?

I unlocked a Galaxy S4 SGH-I337 FROM ATT I am using Tmobile services.
My question is can I install a Stock ROM from TMobile instead of having the ATT one?
I like the Wifi Calling and Tethering option.

I can tell you... But I have a LOT of readers who want to know how to do what you have already done! How did you SIM unlock your SGH-I337? There is a published method for AT&T and TMo that seems to no longer work on the AT&T variant.
OK.. I won't hold you hostage, but I really would like to know!
For the flash to stock, just head over here http://forum.xda-developers.com/showthread.php?t=2267895
Follow the instructions and that will re-flash T-Mobile stock everything.
Sent from my SGH-M919 using Tapatalk

mhannigan said:
I can tell you... But I have a LOT of readers who want to know how to do what you have already done! How did you SIM unlock your SGH-I337? There is a published method for AT&T and TMo that seems to no longer work on the AT&T variant.
OK.. I won't hold you hostage, but I really would like to know!
For the flash to stock, just head over here http://forum.xda-developers.com/showthread.php?t=2267895
Follow the instructions and that will re-flash T-Mobile stock everything.
Sent from my SGH-M919 using Tapatalk
Click to expand...
Click to collapse
Are u sure u can directly odin flash tmo stock unto i337?
Sent from my SAMSUNG-SGH-I337 using xda app-developers app

sharpeyedman said:
Are u sure u can directly odin flash tmo stock unto i337?
Sent from my SAMSUNG-SGH-I337 using xda app-developers app
Click to expand...
Click to collapse
Yes. But also check this thread. The AT&T boot loader is locked and may require Loki Doki patch when you are done.
http://forum.xda-developers.com/showthread.php?t=2295557
Sent from my SGH-M919 using Tapatalk

mhannigan said:
Yes. But also check this thread. The AT&T boot loader is locked and may require Loki Doki patch when you are done.
http://forum.xda-developers.com/showthread.php?t=2295557
Sent from my SGH-M919 using Tapatalk
Click to expand...
Click to collapse
.... I may be wrong here, but since when has it been OK to Odin different carrier's stock .tars? Flashable CWM zips yes, but the bone stock tar with modem, baseband, etc?
Also, being that you have TMO service and an ATT device; flashing a TMO ROM with WiFi calling should work; just use an ATT kernel and the Loki patch. Personally, I'd flash the rooted stock MDL or a custom TouchWiz via CWM or whatever recovery you happen to use and not use Odin.

lordcheeto03 said:
.... I may be wrong here, but since when has it been OK to Odin different carrier's stock .tars? Flashable CWM zips yes, but the bone stock tar with modem, baseband, etc?
Also, being that you have TMO service and an ATT device; flashing a TMO ROM with WiFi calling should work; just use an ATT kernel and the Loki patch. Personally, I'd flash the rooted stock MDL or a custom TouchWiz via CWM or whatever recovery you happen to use and not use Odin.
Click to expand...
Click to collapse
Since wjenmisnit OK to do it differently?
It is only OK to do when you know what you are doing. In this case the hardware is absolutely identical. You're not going to be using AT&Ts baseband firmware on the T-Mobile network are you? Good luck with that.
Mike
Sent from my SGH-M919 using Tapatalk
---------- Post added at 12:24 AM ---------- Previous post was at 12:17 AM ----------
lordcheeto03 said:
.... I may be wrong here, but since when has it been OK to Odin different carrier's stock .tars? Flashable CWM zips yes, but the bone stock tar with modem, baseband, etc?
Also, being that you have TMO service and an ATT device; flashing a TMO ROM with WiFi calling should work; just use an ATT kernel and the Loki patch. Personally, I'd flash the rooted stock MDL or a custom TouchWiz via CWM or whatever recovery you happen to use and not use Odin.
Click to expand...
Click to collapse
MDL baseband is the modem firmware
Sent from my SGH-M919 using Tapatalk

i have the i337 ATT and I am using a Tmobile sim card. Just youtube "unlock galaxy s4 AT&T". There are plenty of videos that use a secret menu to unlock the phone.
Free and instant

I also have AT&T i337 unlocked BUT
I also have AT&T i337 unlocked BUT when I try to use it with MetroPCS (same tower as T-Mobile - companies now merged) I can't get anything but Edge network where on my MetroPCS-supplied phone I get 4G (LTE only rarely) in the same areas. Edge network is ridiculous - can't even load a standard webpage- forget about watching a video! ookla =0.01mps!
So I have an unusable rooted, unlocked S4.
I've tried various APN settings to no avail... Thought I would try liquidsmooth ROM, or any ROM that works on both AT&T and T-Mobile... I assume T-Mobile /MetroPCS would react the same. And I am on a pay as you go plan that is similar to T-Mobile's s. I could easily switch to them if not...
Questions:
Has anyone any advice that could help?
Does anyone know if T-Mobile requires a "pairing" of sim card with phone's IMEI as MetroPCS does? (big pain in the butt)

I've done the same thing flashed roms, Modems, To my luck nothing, I did filing that since I repaired the imei, That is when the problem started. Also to does not tie imei to sims. Did you repair imei
Sent from my SGH-M919 using xda premium

Easy free Sim unlock
Just wanted to point out that if you know someone who has AT&T service they can unlock your phone for free My girlfriend did it for me on their website and it took 24 hours for them to send an email with the unlock code. Just thought i should share that. Up next getting this t-mobile rom onto my 32gb i337 at 4.4.2 with NB1. I hate everything AT&T and God is this phone bloated!

Wanabedev83 said:
Just wanted to point out that if you know someone who has AT&T service they can unlock your phone for free My girlfriend did it for me on their website and it took 24 hours for them to send an email with the unlock code. Just thought i should share that. Up next getting this t-mobile rom onto my 32gb i337 at 4.4.2 with NB1. I hate everything AT&T and God is this phone bloated!
Click to expand...
Click to collapse
Don't they have to be the owner to request an unlock?
Sent from my SGH-M919 using Tapatalk

serio22 said:
Don't they have to be the owner to request an unlock?
Sent from my SGH-M919 using Tapatalk
Click to expand...
Click to collapse
To be honest i can't answer your question. The phone i bought was from a guy who sold it to me out of eBay with a none working screen, he had the imei in the pics so i ran an imei blacklist check and it was clean. I asked him why he didn't fix it and said it was out of warranty so he just left it dead. I guess it was paid for but in his account so it was free for anyone to use but letting my girl do the unlock request worked so if you have a phone that's not blacklisted and you its not associated to an active account I guess it could be done. Try it, it's worth the try.

Similar question
Very first post, not sure if I should have started a new thread. Anyway, I have an ATT S4 I337 with the MF3 baseband. It's rooted, region unlocked, and fully switched to t-mobile service using a method I found on youtube, which worked fairly well except had to modify two things (I can help if you're having trouble). Now I'd like to upgrade firmware (I'm still on 4.2.2). However, I have a lot of uncertainty because of all the changes I've made. If I temporarily unroot, who am I going to get updates from? Do I need TMO or ATT custom ROMs if I want custom (have they solved that bootloader issue yet?). Basically, what's the safest way to update firmware?
Thanks in advance

mhannigan said:
Since wjenmisnit OK to do it differently?
It is only OK to do when you know what you are doing. In this case the hardware is absolutely identical. You're not going to be using AT&Ts baseband firmware on the T-Mobile network are you? Good luck with that.
Mike
Sent from my SGH-M919 using Tapatalk
---------- Post added at 12:24 AM ---------- Previous post was at 12:17 AM ----------
MDL baseband is the modem firmware
Sent from my SGH-M919 using Tapatalk
Click to expand...
Click to collapse
The above also omits that if you are on Android 4.3.X than the bootloader on your Samsung Galaxy S4 contains a bootloader restriction preventing any downgrade which means you would be unable to flash MDL (ie. M919UVUAMDL) since MDL is Android 4.2.2.
Does anyone know a way around this bootloader restriction thereby allowing a downgrade to 4.2.2?

att i337 to t-mob stock
Hi, Im pretty new to this firmware and different model numbers etc.. but here goes. I bought a samsung s4 on att i337 a few months ago off a friend. I paid an online company for the unlock code and received the code within 24 hours. The phone is now unlocked and I have a T-mob sim in it, i'm now looking to update the firmware to t-mobile 4.4.4. Can i download a t-mob stock rom for i337?? I'm worried that this might break the phone as everything I see for t-mob is SGH-M919. Should this matter now that the phone is unlocked?? Thanks

No, you need to use ATT firmware due to hardware differences (antenna/radio). Also as I recall ATT S4s have a locked bootloader meaning only safestrap compatible ROMs can be used, unless something changed since I had one last summer. Sold it, on Swappa, and bought a TMob version with unlocked boot loader and sim unlocked!
Sent from my SGH-M919 using Tapatalk

mfranklin90 said:
Very first post, not sure if I should have started a new thread. Anyway, I have an ATT S4 I337 with the MF3 baseband. It's rooted, region unlocked, and fully switched to t-mobile service using a method I found on youtube, which worked fairly well except had to modify two things (I can help if you're having trouble). Now I'd like to upgrade firmware (I'm still on 4.2.2). However, I have a lot of uncertainty because of all the changes I've made. If I temporarily unroot, who am I going to get updates from? Do I need TMO or ATT custom ROMs if I want custom (have they solved that bootloader issue yet?). Basically, what's the safest way to update firmware?
Thanks in advance
Click to expand...
Click to collapse
Hi! I am having major issues with my s4 i337 after switching from att to tmobile. The phone was unlocked so I took it upon myself to unlock it. It is unlocked but sometimes or rather most of the time does not pick up the network. When it does have data connection, it is Edge. I flashed the NC1 to root my phone, then reflashed to NJ4 (to unlock) but now nothing works. No wifi, camera fails, no multitasker, no voice assistant. Please help!!!!! I don't know what to do. I should have never unrooted it to unlock. I should have paid the $35 to get an unlock code. Can I fix this?

vannicuhh said:
Hi! I am having major issues with my s4 i337 after switching from att to tmobile. The phone was unlocked so I took it upon myself to unlock it. It is unlocked but sometimes or rather most of the time does not pick up the network. When it does have data connection, it is Edge. I flashed the NC1 to root my phone, then reflashed to NJ4 (to unlock) but now nothing works. No wifi, camera fails, no multitasker, no voice assistant. Please help!!!!! I don't know what to do. I should have never unrooted it to unlock. I should have paid the $35 to get an unlock code. Can I fix this?
Click to expand...
Click to collapse
Have you flashed the full firmware?

serio22 said:
Have you flashed the full firmware?
Click to expand...
Click to collapse
I am not sure. I flashed NB1 as suggested by another forum member and everything is working once again. Although it went back to 4.4.2.
Now it has this notification : security notice: unauthorized actions have been detected. It wants me to reboot to revert the changes. How do I make this go away and will it go back to its unusable mode if I manually reboot?
Sent from my SAMSUNG-SGH-I337 using xda Forum

YES
TTAHER said:
I unlocked a Galaxy S4 SGH-I337 FROM ATT I am using Tmobile services.
My question is can I install a Stock ROM from TMobile instead of having the ATT one?
I like the Wifi Calling and Tethering option.
Click to expand...
Click to collapse
i have samsung galaxy s7 edge att unlocked with tmobile sim card and my last 2 ota upgrade are from tmobile G935TUVU4APK1

AT&T Galaxy S III unlocked

Hello,
Sorry if this was asked before but i couldnt find it in the search as its coming up with numerous returns on something else.
Anyways, I bought an AT&T s3 rooted and i was able to put it back to stock with Android 4.0.4. After i put it back to stock i got it unlocked to use on T-Mobile.
My questions are,
how do i update the software to the latest version. do i update it with AT&T software or do i use the T-Mobile software version?
If I update it again will it get locked again?
Rooting is not really an option as it is for my daughters use
thank you in advance for any replies,
V

vreyes said:
Hello,
Sorry if this was asked before but i couldnt find it in the search as its coming up with numerous returns on something else.
Anyways, I bought an AT&T s3 rooted and i was able to put it back to stock with Android 4.0.4. After i put it back to stock i got it unlocked to use on T-Mobile.
My questions are,
how do i update the software to the latest version. do i update it with AT&T software or do i use the T-Mobile software version?
If I update it again will it get locked again?
Rooting is not really an option as it is for my daughters use
thank you in advance for any replies,
V
Click to expand...
Click to collapse
If you update i believe it will no longer be unlocked to use on T-Mobile. However you do need to use the AT&T ROMs for it to work on your phone.

so is it best to root the phone and update it that way.

vreyes said:
so is it best to root the phone and update it that way.
Click to expand...
Click to collapse
You can try updating the phone using the phone's OTA updater. It may not work if you have root.
I don't recommend updating all the way to 4.3 as it will load a 4.3 bootloader which cannot be downgraded and Knox.

What modem should I flash to use a T-Mobile S4 (m919) on At&t network?

So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?

abovenbeyond said:
So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
Any M919 modem. MKL is the newest.

abovenbeyond said:
So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
Glad someone asked that. I looked for a few hours last night and came up empty(been working an off shift so I might have missed it). I am on 4.2.2 MDL and signal is definitely much weaker than my Active on 4.3 . Has anyone compared modems to see which are better?

pahick said:
Glad someone asked that. I looked for a few hours last night and came up empty(been working an off shift so I might have missed it). I am on 4.2.2 MDL and signal is definitely much weaker than my Active on 4.3 . Has anyone compared modems to see which are better?
Click to expand...
Click to collapse
I can provide anecdotal evidence but nothing real...
MK2 is better.
Also, as for which modem to flash; T-Mobile's MK2 would be the one to flash. I've read you can flash other carrier's modems as long as they are the same version, i.e. AT&T MK2 or T-Mobile MK2... but that just doesn't make sense to me and I wouldn't recommend it. The modem you flash is independent of who your carrier is; you go by what brand of phone you have. If you have the M919 then you flash T-Mobile firmwares/modems/etc regardless of which carrier your bill comes from.

abovenbeyond said:
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
I've encountered the same thing with my M919. Switching between Android 4.3 and 4.4.2 modem.bin files made no difference.
I did notice that when I changed my network preference from 3G/2G to 2G-only, I gained about 10 dBa when the handset fell back to GSM-EDGE mode. It made a big difference. I verified that AT&T only uses band II (1900MHz) for GSM and UMTS in my county, so it wasn't because I switched to band V (850MHz) which seems to have better range. What I find annoying is that the handset isn't dropping down to 2G automatically when reception is poor. It'll stick with 3G even when the signal strength is as low as -107 dBa.
No LTE at the moment since my AT&T MNVO doesn't support it.

I'm thinking of buying an M919, carrier unlocked, to use on ATT, so that I can get a proper recovery and have full access to custom ROMs without the safestrap limitations.
Is it safe to say that:
1. If I buy a T-Mobile S4, and it comes carrier unlocked, it will work fine on the ATT network, including 4G / LTE? Lots of data points suggest this but I haven't heard it explicitly stated...
2. Though I could use the phone as identified as an M919, I really want Play Store to see it as an I337 (ATT version), so I can install some ATT specific apps. Is there any problem flashing a build.prop (available in the ATT threads) with the ATT identifiers & APN info, to enable this?
3. Are there any gotchas I should be aware of? Basically, I just want a phone with unlocked bootloader / kernel so I can play. Not too worried about Knox/warranty.
Any insights would be appreciated!
Marc

Frankenscript said:
I'm thinking of buying an M919, carrier unlocked, to use on ATT, so that I can get a proper recovery and have full access to custom ROMs without the safestrap limitations.
Is it safe to say that:
1. If I buy a T-Mobile S4, and it comes carrier unlocked, it will work fine on the ATT network, including 4G / LTE? Lots of data points suggest this but I haven't heard it explicitly stated...
2. Though I could use the phone as identified as an M919, I really want Play Store to see it as an I337 (ATT version), so I can install some ATT specific apps. Is there any problem flashing a build.prop (available in the ATT threads) with the ATT identifiers & APN info, to enable this?
3. Are there any gotchas I should be aware of? Basically, I just want a phone with unlocked bootloader / kernel so I can play. Not too worried about Knox/warranty.
Any insights would be appreciated!
Marc
Click to expand...
Click to collapse
Will the T-Mobile S4 work on the AT&T network; yes it will work if it's carrier unlocked. I purchased my M919 full price out of contract while I was still on AT&T service. Once I carrier-unlocked I was able to pick up AT&T's 4G/LTE and was even able to make use of the AT&T 3G Microcell device which transmits a 3G cell signal and runs over your WiFi. I now have Net10 Wireless with an AT&T SIM card and I still get 4G/LTE when it's around.
Your second question: I do believe that's all that would be required. I'm not 100% sure if just modifying the build.prop would allow you to use the AT&T-specific apps in the Play Store. I never used them to begin with so I never explored whether or not I could make them work on the T-Mobile firmware. Now, I know this involves more than just a build.prop edit, but a 100% sure way to get AT&T Apps working would be to flash a custom ROM based on AT&T firmware. Being that you have a T-Mobile device and are using it on another carrier's network, always remember; when it comes to Odin especially, flash things meant for the T-Mobile M919 ONLY. It doesn't matter that you use AT&T service, your device needs T-Mobile Modems/stock firmwares/etc.
As far as gotchas... not that I can think of. The M919 has an unlocked bootloader and even with KNOX is very easy to root and use custom ROMS on. If you're not concerned with KNOX then you really don't have to take into consideration any special rooting method, no safestrap junk, etc. Without root, just flash a recovery in Odin and flash away.

I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?

flroots said:
I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?
Click to expand...
Click to collapse
@flroots
Basically, you're best off bringing the phone to current M919 stock through ODIN. Is that NK2 or has there been a more recent version? I've lost track. But do the entire phone, and in fact as you will see from some threads it is often necessary to flash it twice in succession to get everything to stick. This will bring you to the latest modem. Remember, the modem is two parts: the modem.bin (also known as the gsm modem, which isn't specifically dependent on the bootloader version you have) and the LTE modem (non-hlos.bin, which is dependent on the firmware version, and bad things happen if you mismatch).
Since your phone is out of warranty, there's no downside to going to the latest, even if the phone arrives with 4.2.2 firmware (pre-knox). Tripping the knox bit is only a problem if you would be sending the phone in for warranty service.
I've got the M919 and am using it on ATT, with no problems. I've got the pre-knox firmware (MDL), and will be updating to the latest next time I flash.
Here is an old, but still relevant, thread about my experiences with M919 on ATT.
http://forum.xda-developers.com/galaxy-s4-tmobile/help/using-t-mobile-m919-att-network-t2880349
You will have to configure your APN to match your Cricket service. Sorry, can't help you with those settings but I'm sure they are on XDA somewhere!
Marc

Frankenscript said:
@flroots
Basically, you're best off bringing the phone to current M919 stock through ODIN. Is that NK2 or has there been a more recent version? I've lost track. But do the entire phone, and in fact as you will see from some threads it is often necessary to flash it twice in succession to get everything to stick. This will bring you to the latest modem. Remember, the modem is two parts: the modem.bin (also known as the gsm modem, which isn't specifically dependent on the bootloader version you have) and the LTE modem (non-hlos.bin, which is dependent on the firmware version, and bad things happen if you mismatch).
Since your phone is out of warranty, there's no downside to going to the latest, even if the phone arrives with 4.2.2 firmware (pre-knox). Tripping the knox bit is only a problem if you would be sending the phone in for warranty service.
I've got the M919 and am using it on ATT, with no problems. I've got the pre-knox firmware (MDL), and will be updating to the latest next time I flash.
Here is an old, but still relevant, thread about my experiences with M919 on ATT.
http://forum.xda-developers.com/galaxy-s4-tmobile/help/using-t-mobile-m919-att-network-t2880349
You will have to configure your APN to match your Cricket service. Sorry, can't help you with those settings but I'm sure they are on XDA somewhere!
Marc
Click to expand...
Click to collapse
Thanks a lot for that update. As I understand it, the current firmware is NB4 according to this site:
http://galaxys4root.com/galaxy-s4-stock-firmware/
Not sure what your reference to NK2 is? That doesn't seem to correspond to either 4.2.2 nor 4.4.2? I'm currently on Cricket with a S4 I337 and hope to move the SIM over as soon as my M919 arrives tomorrow.

I believe after NB4 there was NH7 then NK2. Check the firmware thread in the general section for details / links.
Sent from my SGH-M919 using Tapatalk

@flroots
How did this work out for you? I want to do the same thing you said you where going to do.
flroots said:
I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?
Click to expand...
Click to collapse

Robert417919 said:
@flroots
How did this work out for you? I want to do the same thing you said you where going to do.
Click to expand...
Click to collapse
Robert417919,
I use my SGH-M919 on an AT&T network also. I use the OK3 modem firmware and it seems to work great here. Although I am in Alaska, so top speeds of LTE are only about 6 Mbps where I live. Usually I can only get about 3 Mbps due to the lack of coverage around here.
You can either update to the latest OH3 firmware on your phone, or if you have an old model, with the MDL bootloader, you could also use this guide by lordodin912:
http://forum.xda-developers.com/galaxy-s4-tmobile/general/foh3-modem-bin-mdl-bootloader-t3191094
Also, if you are looking for good roms, you can always check out SlimLP:
http://forum.xda-developers.com/galaxy-s4-tmobile/development/rom-slimlp-jfltetmo-t3377731
Or Resurrection Remix:
http://forum.xda-developers.com/gal...ent/rom-resurrection-lollipop-v5-4-5-t3115155
Hope that helps!

Thanks, this does help out, and another quick question. Are you able to use wifi calling?
AlaskaLinuxUser said:
Robert417919,
I use my SGH-M919 on an AT&T network also. I use the OK3 modem firmware and it seems to work great here. Although I am in Alaska, so top speeds of LTE are only about 6 Mbps where I live. Usually I can only get about 3 Mbps due to the lack of coverage around here.
You can either update to the latest OH3 firmware on your phone, or if you have an old model, with the MDL bootloader, you could also use this guide by lordodin912:
http://forum.xda-developers.com/galaxy-s4-tmobile/general/foh3-modem-bin-mdl-bootloader-t3191094
Also, if you are looking for good roms, you can always check out SlimLP:
http://forum.xda-developers.com/galaxy-s4-tmobile/development/rom-slimlp-jfltetmo-t3377731
Or Resurrection Remix:
http://forum.xda-developers.com/gal...ent/rom-resurrection-lollipop-v5-4-5-t3115155
Hope that helps!
Click to expand...
Click to collapse

Robert417919 said:
Thanks, this does help out, and another quick question. Are you able to use wifi calling?
Click to expand...
Click to collapse
Glad to help, and no, unfortunately not.
-AlaskaLinuxUser
https://thealaskalinuxuser.wordpress.com

Help with updating ATT branded Note4 on Tmobile.

I've got a friend who purchased an unlocked Note4 with ATT branding and software. She uses it on Tmobile. I noticed recently while googling that it looks like currently note4 on ATT is on marshmallow. However, when i try updating the phone it says its already up to date. The phone is currently on 5.1.1. Not sure why it's not updating. Could it be because it's on Tmobile as the carrier since its an ATT branded phone? How would I go about updating it?
android version 5.1.1
model SAMSUNG-SM-N910A
baseband N910AUCU2DOI2

unvaluablespace said:
I've got a friend who purchased an unlocked Note4 with ATT branding and software. She uses it on Tmobile. I noticed recently while googling that it looks like currently note4 on ATT is on marshmallow. However, when i try updating the phone it says its already up to date. The phone is currently on 5.1.1. Not sure why it's not updating. Could it be because it's on Tmobile as the carrier since its an ATT branded phone? How would I go about updating it?
android version 5.1.1
model SAMSUNG-SM-N910A
baseband N910AUCU2DOI2
Click to expand...
Click to collapse
I was in the same situation, and discovered an XDA thread that allowed me how to update my note4.
It's as simple as downloading the official at&t updates onto your sdcard and apply onto your phone.
It's a long thread, but well worth the read:
https://forum.xda-developers.com/no...t-server-link-installation-t3407308?nocache=1

DO12 missing?
mr_manny said:
I was in the same situation, and discovered an XDA thread that allowed me how to update my note4.
It's as simple as downloading the official at&t updates onto your sdcard and apply onto your phone.
It's a long thread, but well worth the read:
https://forum.xda-developers.com/no...t-server-link-installation-t3407308?nocache=1
Click to expand...
Click to collapse
I really appreciate the hint. i just recently got a new note4 (obvioulsy im not in the U.S) and cant get updates like you. Im very new to samsung (mod,flashed the shaiza out of my m8 and nexus 7, but this is new territory)
when i saw the link you shared it has the following
EPH5 to EPH7.
DOI9-to-EPH5
DOI7 to EPH5
DOI6-to-EPH5
i dont see DOI2.
can you please help me out with a few more hints as to what you did to get the latest update available... (i know about placing the files on sd and bootlader, select update etc)
but do i have to manually install every update to reach the last one?

ichiai said:
i dont see DOI2.
Do i have to manually install every update to reach the last one?
Click to expand...
Click to collapse
I guess you didn't make it to page 161
Start with page 161, then go back to the 1st page of the thread and download all updates/patches.
https://forum.xda-developers.com/no...stallation-t3407308/post69995836#post69995836
https://forum.xda-developers.com/no...hmellow-att-server-link-installation-t3407308
I performed every step one-at-a-time.
Another option is to utilize ODIN (software) to jump steps, but it requires windows.
I don't do windows
Remove the back cover (so the phone doesn't overheat), and take your time...it will take a while

mr_manny said:
I guess you didn't make it to page 161
Start with page 161, then go back to the 1st page of the thread and download all updates/patches.
https://forum.xda-developers.com/no...stallation-t3407308/post69995836#post69995836
https://forum.xda-developers.com/no...hmellow-att-server-link-installation-t3407308
I performed every step one-at-a-time.
Another option is to utilize ODIN (software) to jump steps, but it requires windows.
I don't do windows
Remove the back cover (so the phone doesn't overheat), and take your time...it will take a while
Click to expand...
Click to collapse
you Godsend! thanks for confirming. will get back to reading -->
stay blessed

Another way to update AT&T devices on that aren't on AT&T is to get an AT&T SIM (99¢ on the AT&T GoPhone site), activate it on GoPhone but don't add any funds. The unfunded SIM won't let you make calls, send texts or use AT&T data but it will let you get OTA updates on WiFi.