How to Install GT-i9505/T-Mobile Custom ROMs on AT&T Galaxy S4!

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In theory, since international LTE model GT-i9505 and T-Mobile Galaxy S4 SGH-M919 share the exact same hardware as AT&T Galaxy S4 SGH-i337, it should be possible to install GT-i9505/T-Mobile custom ROMs on your AT&T Galaxy S4.

Well, I tried it today and it works just fine. You will need to install a custom kernel such as KTweaker kernel after installing ROM though to bypass the locked bootloader on your AT&T Galaxy S4.

For Canadian SGH-i337M users, you don’t need to install a custom kernel, just install any GT-i9505/T-Mobile custom ROMs and they should work out of the box but do check for modem in the ROM file also.

To install GT-i9505/T-Mobile custom ROMs on your AT&T Galaxy S4:

First, make sure there’s no modem.bin file in the custom ROM zip file. You can easily check this by opening the ROM zip file.

Second, make sure you are using GT-i9505 custom ROMs NOT GT-i9500! GT-i9500 uses different Octa-core CPU, meaning you can hard-brick your phone so just make sure you are using GT-i9505 or T-Mobile custom ROMs.

Third, you can use TWRP or CWM recovery. If you get Status 7 Error during install, you need to remove asserts using this method.

Fourth, installation is easy, just install the ROM normally but after installing ROM, install KTweaker kernel. See video tutorial if you don’t get it.

Use TouchWiz kernel for TouchWiz-based ROMs:
Download KTweaker TouchWiz kernel for AT&T Galaxy S4 SGH-i337

Use AOSP kernel for AOSP ROMs (What is AOSP?) such as CM10.1, AOKP, ParanoidAndroid, etc…:
Download KTweaker AOSP kernel for AT&T Galaxy S4 SGH-i337

If you lose 4G LTE after installing ROM, make sure your Network Mode is set to “LTE/GSM/WCDMA” under Mobile Networks in settings.

Also, set APN (Access Point Names) in Mobile Networks to:

Name: PTA
APN: pta
MMS Proxy:
MMS port: 80
MCC: 310
MNC: 410
Auth: none
APN type: default,mms,supl,hipri

More Notes

I was able to fully install a T-Mobile ROM on my AT&T Galaxy S4 and turn my AT&T GS4 into a full T-Mobile GS4 with wifi-calling/HSPA+ working. You will need to also enable AWS bands on your AT&T GS4 if you want to use T-Mobile SIM card.

Credits – KTweaker on XDA <— Please donate to the developer of KTweaker kernel or hit “Thanks” on XDA, thx!

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61 Responses

  1. curtis says:

    sup max… i did everything, got the rom up and running but i cant seem to get wifi to work… keeps getting this prevention message and asking to reboot… can u help?

    • Max Lee says:

      which ROM? Did you flash the kernel? If you don’t flash the kernel after installing ROM you will get that prevention message.

      • curtis says:

        Yea I installed the wanamlite for gti9505 on my at&t i337. And I did flash the kernel from this download link above..

      • William says:

        Which kernel do I use? The touchwiz one? Download KTweaker TouchWiz kernel for AT&T Galaxy S4 SGH-i337

      • Nsir Malik Islamabad says:

        Dear Max,
        I am your follower!
        My at&t galaxy 4 s was giving errors. It had MF3 based band version. I tried Kies to restore/upgrade & it failed.
        Now it says Upgrade error encountered, try Kies. Many tries & then emergency recovery. That also fails.
        Please help me to get my S4 back alive.

  2. clay says:

    Hey Max what about sprint sph-l720. Need call recording badly no one has stepped up, I think you can handle this…

  3. alex says:

    Hey Max…is it possible to flash on top of stock rooted att rom?

  4. alex says:

    Or do I need to wipe

  5. Landon Barnes says:

    Flashing Wicked and the kernel. Got the message “system software not authorized by AT&T has been found on your phone”. Not sure what to do.

  6. avatarr says:

    Same issue as Landon above. SGH-i337, AT&T.

  7. Kyle says:

    Any idea as to what I did wrong to get this message at first boot? “System software not authorized by ATT has been found on your phone”

  8. Alex says:

    I got that error when I flashed the rom and booted the phone without flashing the kernel…..At first I flashed the omega rom and kt kernel and it booted up with no issues not even the custom logo. Then I realized there were still a few bugs like the camera with the updating firmware message. People said to flash the rom first, boot once and flash kernel. When I did that I got the same message you guys are getting. Ever since then I got the custom logo. Reverted back to original rom and still had custom. I tried numerous methods to unroot and still stuck with custom logo. Got annoyed and odined original rom and rerooted and custom logo is gone and the phone is back to my original state. I’m not flashing any roms until this crap gets fixed…

    • landon says:

      can you send me the steps for exactly how you got it back to normal? or post the steps here?

  9. Alex says:

    Hi landon all I did was download the factory rom and flashed it via Odin. After flashing I went into recovery and formatted all data and reboot. When I rebooted the 2nd time the custom logo was gone. I then went and downloaded the motochopper root and rerooted. Should take less than an hour. The only mistakes I made was not saving my data with titanium in my sd card. I thought I saved it there but didn’t so I had to redo everything.

  10. Alex says:

    Yes I downloaded from max’s site… Very easy to do. Since Max is busy I will try to help you as much as I can.

  11. Landon says:

    So, i have the Stock ATT downloaded. I just put my phone in download mode and go through Odin with that file?

  12. Alex says:

    That is correct sorry I didn’t go into greater detail. ..

  13. Landon says:

    Sorry for all the questions. The file extension for the stock ROM doesn’t have to be a .tar for Odin?

  14. Alex says:

    Its all good! Just trying to pay it forward by helping others. . Yes all you have to do is extract the tar file…

  15. avatarr says:

    I think the reason we were getting the “not authorized by at&t” error was because the tutorial that is linked in this blog post actually links to the t-mo ktweaker kernel, not the appropriate at&t kernel.
    ( is the wrong one.) This one is the right one:

    I finally stumbled upon the right one. I had to odin restore stock firmware, use CASUAL to re-install twrp. These are the steps I took:
    -Full wipe
    -Flash Wicked ROM
    -Flash correct kernel (linked above)

    I wasn’t sure if I also had to flash gapps but just to be safe, I didn’t. When I rebooted, it sat on the flashing Wicked boot screen for a while (what looks like an animated MRI of a spine). Finally it booted up and it worked great. Play store was already there, and I believe gmail was as well. I am not completely sure, however, since I used my Google account for app sync on a previous flash and I connected to it upon this boot and it installed the apps I had installed before. So far I’m liking the Wicked ROM. It’s much snappier than stock since it’s missing all the Samsung crap. I did try a Cyanogenmod 10.1 nightly for the S4 but it was having too many issues (incoming calls not showing up and unable to hang up outgoing calls). There are things about it that I miss (like lock screen widgets) but the Wicked ROM, at least for me, is a good compromise. Definitely stable.

    Thanks to galaxys4root for the video / tutorial. I wouldn’t be where I am now without it.

  16. Cristiano says:

    I`m sorry friends, but I have a conceptual question: how can I start the installation if the Volume Up, Center Home, and Power buttons doesn`t enable the CWM recovery, since bootloader is locked? I have a AT&T model, wich bootloader is locked, as we know.

    Where I can get a s4 custom rom, like the samsung original?

    Now, Max please: when you finished the process, you saw the 16 gbs?? Thank you! Appreciated,

    Cristiano, Rio, Brasil

  17. Joe says:

    Did not work on my att.
    i got the same message as the others.
    i almost got locked out, phone didnt want to boot into twrp.
    took out the battery for 10 sec and tryed again and went into recovery.
    restored back to my back up right before i did the proccess. just want to know why it is not working.
    fallowed the video to the T. let me know if there is a fix for this .


    • Alex says:

      Hi joe… i was able to successfully flash both omega and wanam lite without the warning it was when I tried to restart without flashing the kernel that I got that warning. Did you forget to flash the kernel right after you flashed the rom?

      • joe says:

        I rooted it with moto and tryed doing cwm wouldent work so then I went with goo manger.
        After that downloaded the wicked rom and the kernal that was on this site. made a back up with twrp.
        DId a data wipe. Installed the rom and then iinstalled the kernal. Rebooted and went to the att screen. Did everything that was on the video but I could be midsing something here. What do you meen by flashing both omegs and wanam? Not a noob. Just been a while since ive had an android. Last time ive done this was 2 years ago with the htc aria.

        Thsnk you for the responce

  18. Alex says:

    Hi cristiano… It is possible to flash with locked bootloaders. Follow max’s guide step by step and install twrp recovery. It’s fairly easy to do. …

  19. Alex says:

    I meant I flashed each rom once to try out. Not flashed both at the same time lol
    My steps were….
    -root with moto
    -install twrp through goo
    -go into recovery and factory reset/wipe
    – flashed rom
    -flashed kernel(kt)
    -rebooted to new rom with no issues.

    Are you sure you have the right kernel?

    • joe says:

      When you mean flashed the rom and then flashed the kernal youn mean you selected install like the video showen. I used the one up above. I downloaded the wicked v3 rom for t-mobile and the kernal at the top of the page. I select wipe data. then install wicked v3 rom and then when its done I go back home goto install again and select the TW kernal like I said and then I reboot and boom att bull crap lol. Im still not seeing what im doing wrong the video is pritty strait foward

  20. Alex says:

    Yes I did it just like the video. You sure you are using the touchwiz kernel correct? did you try any other rom or try redownloading the same rom? Maybe you got a bad download?

  21. John says:

    Followed the steps and my phone won’t even turn on now, I get Samsung – Custom screen and it just shuts off.

    I can hold Volume Down, Power, Center Home and get to install custom OS screen and that’s it.

    I did:
    -root with moto
    -install twrp through goo
    – go into recovery and factory reset/wipe
    – flashed rom (Foxhound)
    – flashed kernel(kt) – (AOSP version)

    What are my options?

  22. Alex says:

    I would restore backup or try to flash stock rom back and reroot.

  23. STEVE says:


  24. Alex says:

    Hi Steve…. you can use any ATT kernel. I myself am using KT Kernel. I’m sure you may have an issue first with the camera trying to update its firmware. If you flash KT kernel first you will not be able to update camera firmware and everytime you load the camera you will see that message. You should first flash rom and then flash a stock loki kernel like MDOB kernel then start the phone and make sure you open the camera app first. It will update and download firmware and then you can go back to recovery and flash KT Kernel. Let me know if you need help….

  25. Tim says:

    When I activate USB debugging my computer no longer recognizes my device. I’m attempting to root the device. I have unlocked the SIM and have been using it on T-Mobile for about a week now. It is the ATT SGH-1337. Please help…

  26. Cristhian says:

    Installed Omega v5 on Canadian S4 (i337) and installed KTweaker JB TW for ATT and the phone just reboots and reboots. The issue with Omega v5 is that wifi doens’t work and the phone gets stuck on Galaxy S4 screen after reboot or power down. Suggestions?

    • Cristhian says:

      Would the Adam Kernel help in this situation? It’s almost stock XXMUEA right?

    • Cristhian says:

      Never-mind the ROM won’t work properly because I need to have the latest International S4 Firmware installed in order to get all things to work on the ROM. That’s why it’s acting up.

  27. Pak says:

    On the page on how to install custom ROM, it says putting i9505 on i1337 will brick the phone, Which one am I supposed to trust now? I am one step away from installing the ROM, literally. My mom desperately need chinese on her S4, and the only way is to install 9505.

  28. Mohammad Salam says:

    Hi, can i follow this instructions and install any tmobile rom to this at&t phone and get lte? Thanks.

  29. iphone h8r says:

    How can I do the opposite?? Installing AT&T rom on T-Mobile version. Tried several times but failed


    • Pak says:

      I don’t know much, but I bet you need a different kernel then the one noted in the instruction. But I don’t know.
      No one replied mine yet so far…

  30. mike says:

    should i change in build prop anything that has jflte to jflteatt? i have the sgh-i337. would that mess up updates etc etc?

    • Max Lee says:

      You don’t have to but you can, it won’t really mess up anything, most custom ROMs have updates disabled anyways.

  31. mike says:

    So I change it also put the correct model (i337) and got my 4glte icon back ^_^

  32. Nadir says:

    Flashed the Google Play ROM on an AT&T i337 and everything is working except for MMS. I checked the APN settings and they’re the exact same as noted above. LTE / WiFi / everything else works fine. It’s just MMS. Any ideas?

  33. john says:

    Once aws bands are enabled on my att galaxy s4 and I make
    a factory reset. Do they stay permanently or should I redo the process?

  34. j papa says:

    Hey so I flashed the t-mobile aws band qcn file on my sgh-i337 without being rooted. I could access recovery and tried witusing odin and kies with still the same results. Any help would be greatly appreciated

  35. Rafael says:

    I tryed the process. Intalling a i9505 rom on a T-mobile m919, when I put to install the rom via Odin it fails and the S4 screen shows:
    and the room doesn’t install
    how can I solve this and install the brazillian rom on a T-mobile S4?

  36. scotty says:

    How about running a carriers rom but different modem like on tmobile but at&t modem or kernal?

    • Max Lee says:

      You cannot install another modem on another model of S4. E.g. You can only install Tmobile modem on Tmobile S4.

  37. arthur says:

    Hello..I am trying to unlock a Best Buy Blue S4 Sprint network phone to work with Simple Mobile. .. Any help or ideas from anyone. . I could really use the advice.. thanks

  38. bryan says:

    Old post but FYI I installed this:

    Google Edition Galaxy S4 for i9505
    Enjoy pure android 4.2.2-4.3-4.4 and 4.4.2 Odexed & deodexed Full rooted & busybox

    With TRWP on my Canadian Bell sgh-1337m phone, now using on Wind Mobile after fixing radio to use AWS bands and it works great including s-view for my cover which is what I was after.

  39. Joseph says:

    In the video you said that this is possible for Sprint and Verizon Galaxy S4s (Meaning to flash Tmobile Rom over them and having it working as Tmobile phone + wifi calling). Did you do this? Will it work if I do that to Verizon phones?


    • Max Lee says:

      Yes it should work. Tmobile ROMs probably won’t work for Sprint/Verizon without a patch but should work fine for GSM carriers. Also, not sure on Sprint as its usually locked for U.S. GSM networks, may work outside U.S. tho.

  40. phillip says:

    Will this work on an AT&T GS4 with a locked boot loader? My GS4 came with 4.4.2 installed, and a locked boot loader. The only ROMs I’ve been able to install thus far have an option in the Aroma installer for AT&T Safestrap users. I think it doesn’t write the kernel in these cases.

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