How to flash a AT&T Galaxy S9 SM-G960U with a T-Mobile Stock Rom?

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17mm

Senior Member
Apr 9, 2013
75
12
so i have the at&t version g960u, if i flash u1 firmware will i then have "oem unlock" option in developer options?
 

17mm

Senior Member
Apr 9, 2013
75
12
i flashed U1 firmware just fine, it finished with no problems and showed my phone as U1 in settings, i tried to flash to TMO and it went back to just at&t, tried sprint and verizon too all said success but phone says erasing as it boots and boots with at&t logo, whats going on?, i like the U1 unbranded look but its clocked at 2.5Ghz wheras just the U is clocked at 2.8, 300Mhz may not be much but i would rather have that option plus unbranded at&t junk. what should i do?
 

jcsww

Senior Member
i flashed U1 firmware just fine, it finished with no problems and showed my phone as U1 in settings, i tried to flash to TMO and it went back to just at&t, tried sprint and verizon too all said success but phone says erasing as it boots and boots with at&t logo, whats going on?, i like the U1 unbranded look but its clocked at 2.5Ghz wheras just the U is clocked at 2.8, 300Mhz may not be much but i would rather have that option plus unbranded at&t junk. what should i do?

Do you have the SIM of the carrier firmware you are flashing to in the device when flashing from U1 to U? Are you using the HOME_CSC, because that prevents conversion?
 

Youdoofus

Retired Forum Moderator
Feb 21, 2011
3,507
1,022
Sioux Falls, SD
Samsung Galaxy S9
i flashed U1 firmware just fine, it finished with no problems and showed my phone as U1 in settings, i tried to flash to TMO and it went back to just at&t, tried sprint and verizon too all said success but phone says erasing as it boots and boots with at&t logo, whats going on?, i like the U1 unbranded look but its clocked at 2.5Ghz wheras just the U is clocked at 2.8, 300Mhz may not be much but i would rather have that option plus unbranded at&t junk. what should i do?

it sounds like youre flashing the CSC file instead of the HOME_CSC. These phones are all literally identical for the USA market and can easily have the U1 firmware flashed on it to remove all carrier crap. Thats exactly what i did with mine. Are you using patched Odin? I assume so, because otherwise youd be reporting failures with that.
 

17mm

Senior Member
Apr 9, 2013
75
12
Do you have the SIM of the carrier firmware you are flashing to in the device when flashing from U1 to U? Are you using the HOME_CSC, because that prevents conversion?

i dont have a sim card, using HOME_CSC to flash the new U firmware, like i said the U1 firmware flashes just fine its when i try other U firmwares that it says erasing as it boots after flash then boots as at&t again with no changes.
 

jcsww

Senior Member
i dont have a sim card, using HOME_CSC to flash the new U firmware, like i said the U1 firmware flashes just fine its when i try other U firmwares that it says erasing as it boots after flash then boots as at&t again with no changes.

The HOME_CSC prevents conversion by preserving data that needs to be wiped. It might flash successfully, but it isn't erasing and writing over what it needs to because the HOME_CSC is being used. Using the SIM card of the carrier firmware you are flashing to helps because it specifies what needs to be configured on setup. Otherwise, it will just assume you are going to be using the same carrier the device was originally configured for.
 

Youdoofus

Retired Forum Moderator
Feb 21, 2011
3,507
1,022
Sioux Falls, SD
Samsung Galaxy S9
The HOME_CSC prevents conversion by preserving data that needs to be wiped. It might flash successfully, but it isn't erasing and writing over what it needs to because the HOME_CSC is being used. Using the SIM card of the carrier firmware you are flashing to helps because it specifies what needs to be configured on setup. Otherwise, it will just assume you are going to be using the same carrier the device was originally configured for.

i have a Cricket S9 that i flashed the U1 firmware on and the bootanimation logo went away even tho i didnt take my sim out during the process. The at&t logo remaining on boot is weird to me, but ive only debranded 2 S9's
 

rwpirani

New member
Jan 3, 2013
1
0
Pineville, Kentucky
Hello,
On this April 13,2018 post by By jrockz3000 : “How to flash a AT&T Galaxy S9 SM-G960U with a T-Mobile Stock Rom?”
The 4/14/18 post It gives instructions: To Flash the SM-G960U to a SM-G960U1.
My S9 SM-G960U snapdragon AT&T unlocked phone with the locked bootloader. Being my provider is Straight talk, it won’t let me hotspot nor wifi call. So,I was hoping to flash to a SM-G960U1, and get rid of AT&T.
My question is:
Will this process work on my bootloader locked phone?
If it will, the U1 firmware, link in the post, appears to be different than the U1 at sammobile. So I downloaded both.
Thank you for your time and assistance.
 

AsianCajun

Member
Oct 1, 2012
40
22
Reviving this thread. I was having issues with my AT&T SM-G960U device because my carrier was though T-Mobile. My process was the same. Flash with a U1 rom then the T-Mobile rom. Just updated roms because my phone was already on andoid 10 (Q). I started with a U1 rom Here. Which ended up in a recovery loop. I was still able to get into download mode. I then flashed the latest T-Mobile rom here.
 
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  • 7
    I've done it!

    Any chance anybody has success doing this? It seems like a "Must Have" feature to switch carrier roms on the G960U between carriers, including Boot Screen/Logo, Firmware, Bloatware, etc.

    All the goodies.

    Any help?

    Thank you,

    I've completed this task tonight thanks to some great help from a user that stepped me through it on a TMO Forum.

    First an FYI, I first was able to flash my AT&T S9 version from SM-960U to a Stock SM-960U1. It worked great. After that, I was able to flash the TMO Rom and it's also working perfect. I'm not sure if it's required or not to flash the phone to a U1 first or if the TMO Rom can just be flashed. After I flashed the TMO firmware, I had no issues downloading and installing the latest TMO update. (My device is unlocked as well)

    It's best to use Samsung switch first to backup your texts, pics, etc. first if you want to restore them to the device after completing the flash. The below instructions will start the phone up as if it was new out if the box.

    Here is what I was provided with and the steps I followed.

    To Flash the SM-G960U to a SM-G960U1

    1. Allow\Enable USB Debugging in Developers settings.

    2. Download the U1 Firmware here: https://androidfilehost.com/?w=files&flid=257063
    (this is the U1 from Samsung, it's compressed but once extracted it will be around 4GB's of data.)

    3. Download the ADB tools: https://devfiles.co/download/PDYvOWBg/platform-tools-latest-windows.zip. Create a folder on your desktop and name it ADB (for easy reference)

    4. Download Odin: https://drive.google.com/file/d/10dSyPTuccP8Km9MnDrvbRdS-CAcgFZB3/view

    5. From windows, run command prompt, in the command prompt type the following: cd C:\Users\XXX\Desktop\ADB
    (XXX is your username)

    6. Connect your phone to a USB port on your computer, your phone should prompt you to allow the connection to\from your computer. Allow the connection. Might be best to choose to "Always Allow"

    7. Return to the command prompt and type in: adb devices You should see your device listed.

    8. In the same command window, type in: adb reboot bootloader This will auto reboot your device into the "Download" mode.

    9. Open and run Odin, add the corresponding tar files to the respective area's, in the "options tab" in Odin, make sure that only "Auto Reboot" and "F. Reset Time" is checked.

    Click "Start" and the process will take a few minutes to complete.

    Allow the device a few minutes to auto reboot and start up.

    After you get through all the post boot setup screens, open a phone dial pad and type in, *#2263#. then make sure that all LTE bands are enabled.

    Here you can find the SM-G960U T-Mobile Files: https://www.droiddosh.com/2018/04/samsung-galaxy-s9-sm-g960u-firmware-tmobile-usa-G960USQU1ARBG.html
    1
    B"H

    Ok, thank you.

    1. So stock G960U (Original Carrier) -> Flash to U1 -
    2. Then, Go from G960U1 -> Stock G960U (Any Carrier)

    Few questions:
    1. Which CSC file are you using to flash -- CSC_HOME?
    2. In moving from U1 -> U, do you need the final carrier SIM inside the phone?

    I've tried this with a Verizon phone I'd like to convert to XFinity (CCT). I flashed the G960U VZW to G960U1 XXA. That worked fine. Then I flashed the G960U CCT rom, and the phone just boots up Verizon. When I check the CSC, it says "VZW/VZW/VZW", even though I flashed the CCT rom.

    I don't have an XFinity sim card, so perhap that is the problem.

    Any help would be great.

    You most likely will need a Xfinity Sim Card. I was able to convert my Xfinity Mobile S9 to AT&T by going to U1 firmware then inserting my AT&T sim card then flashing the AT&T U firmware.
    1
    Question

    Does anyone know if you have to have the phone unlocked before changing over carriers? for example if i had a Galaxy S9 from Sprint and wanted to change the firmware to T-Mobile would it work or would it still be locked to Sprint? Thanks for your Help!
    1
    Can anyone help please ODIN file is not available.

    You can find it here.
    1
    Thanks, I have a question, I am try to flash T-Mobile ROM on xifinity S9 that has android 8 on it. should I proceed with the same process. or get the latest T-Mobile ROM. Please help

    You need to factory wipe and flash to the U1 non-carrier specific firmware first after enabling USB Debugging in the Developer Options once you factory reset. Pop your T-Mobile SIM in and put the device into download mode. Make sure you find the U1 version that has the same or a newer bootloader than your device currently has. You can not flash a previous version of the bootloader. Do not use the file called, HOME_CSC when flashing any of the firmware unless you want the potential for issues. Once you flash the U1, skip through the setup, don't activate WiFi or sign in with your Google account and head straight to enable USB Debugging once again in Developer Options. Back into download mode and flash the TMB firmware, again making sure you don't flash the HOME_CSC (there is another CSC that does need to be flashed) and everything should be good.