How get back your carrier services if you changed your CSC code.

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herald1368

Senior Member
Apr 2, 2016
60
6
Cross flash in Note 20 5G series

How get back your carrier services if you changed your CSC code



Well with the help of these great XDA members I was able to restore my carrier services to my ATT 986U branded phone.

I made the mistake of messing with the CSC code without doing enough research. The mistake I made was using the procedure below on my 986U when it was meant for 986U1.

(I just pulled my SIM, entered *#272*MY_IMEI# and changed CSC from ATT to XAA. Rebooted phone without SIM and checked for update.)

Doing this made my phone lose all of its carrier services and I could not revert back. Luckily with the help of the XDA members they provided a tutorial on how to restore the ATT carrier services. It has been confirmed to work on Verizon and maybe other carriers. Follow the instructions below provided by @mlr_90.

1. First Flash your device with the U1 firmware found here using the patched Odin3_v3.13.3b: https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
2. Second make sure you flashe the AP,BP,CP and CSC found in the file. (Not the HOME_CSC)
3. Make sure to remove your sim card when you flash rom. Reinsert the sim card once phone is booted up and done with the initial setup. Once setup is done pop in your carrier sim card and you should get a message stating to reboot your phone. This will change your CSC code back to ATT/ATT/ATT from XAA/XAA/ATT.
4. Once your phone reboots confirm in the software information that your CSC is back to ATT/ATT/ATT
5. Now you can flash back to the U version firmware. Currenlty the latest is ATI6 found here https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
6. Flash using the U firmware using the instrucitons in step 2, but this time make sure your flash the HOME_CSC instead of the regular CSC.
7. Once this is completed flashing you should see your carrier logo during bootup and all the carrier services will be back on your phone.

Special thanks to
@mlr_90
@kangi26
@butchieboy
@warriorvibhu
@testrak

Can I flash Note 20 ultra 5G firmware on note 20 5G? is it possible by any means? with root or without root? Any one know this? Thanks
 

jeremyvbk

Member
Feb 10, 2014
43
11
Very interesting find is on ATT, if you do the *#272* code and change to XAA, I did not get a true 5G connection, just the LTE with the 5G upper layer Indicator showing 5G on the phone
 

bwhsvid

New member
Oct 15, 2020
1
0
Confused

I guess I’m confused on what u1 software version I am to use. I screwed mine up to XAA and trying to get back to att. Any help is much appreciated.
 

ubaid5832

New member
Dec 13, 2020
1
0
Hello friend !
I am syed from Qatar. I using samsung note 10+ SM-975U but unfortunately firstly its CSC based on At&T but I changed *272*imei# to CSC GCF.. Now I trying to calling or sending message but its not sending.. now I want to get back AT&T file..I flashed firmware 2 times but its don't working... Any body help to me????
 

bighleo114312

Senior Member
Dec 1, 2012
676
70
zacatecas
OnePlus 7 Pro
Very interesting find is on ATT, if you do the *#272* code and change to XAA, I did not get a true 5G connection, just the LTE with the 5G upper layer Indicator showing 5G on the phone
I dont understand,
How get back your carrier services if you changed your CSC code



Well with the help of these great XDA members I was able to restore my carrier services to my ATT 986U branded phone.

I made the mistake of messing with the CSC code without doing enough research. The mistake I made was using the procedure below on my 986U when it was meant for 986U1.

(I just pulled my SIM, entered *#272*MY_IMEI# and changed CSC from ATT to XAA. Rebooted phone without SIM and checked for update.)

Doing this made my phone lose all of its carrier services and I could not revert back. Luckily with the help of the XDA members they provided a tutorial on how to restore the ATT carrier services. It has been confirmed to work on Verizon and maybe other carriers. Follow the instructions below provided by @mlr_90.

1. First Flash your device with the U1 firmware found here using the patched Odin3_v3.13.3b: https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
2. Second make sure you flashe the AP,BP,CP and CSC found in the file. (Not the HOME_CSC)
3. Make sure to remove your sim card when you flash rom. Reinsert the sim card once phone is booted up and done with the initial setup. Once setup is done pop in your carrier sim card and you should get a message stating to reboot your phone. This will change your CSC code back to ATT/ATT/ATT from XAA/XAA/ATT.
4. Once your phone reboots confirm in the software information that your CSC is back to ATT/ATT/ATT
5. Now you can flash back to the U version firmware. Currenlty the latest is ATI6 found here https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
6. Flash using the U firmware using the instrucitons in step 2, but this time make sure your flash the HOME_CSC instead of the regular CSC.
7. Once this is completed flashing you should see your carrier logo during bootup and all the carrier services will be back on your phone.

Special thanks to
@mlr_90
@kangi26
@butchieboy
@warriorvibhu
@testrak
Hi my friend, I dont know of this will help me with my problem. I have an unlocked 20 ultra with the u1 firmware. I was using a MetroPCS sim card and had 5g working good. Now I'm at cricket and I only have lte+. And in network I domt have options to change 5g/lte/..etc. and I was told there is 5g where I live. So what could I do to get the option to choose in a 5g mode? Thanks in advance
 

TabletGeek

Senior Member
Jan 4, 2012
64
23
It is great to have such helpful people here on XDA! Thank you @borijess for posting this and thank you to all the members who helped provide the information for this solution!

I now have a problem (perhaps a different cause?) and I hope someone can help me to resolve this. I just flashed my new SM-986U (locked to TMO) to the USC (unlocked) version of the stock ROM N986USQS1BTK3 (from SAMMOBILE). Odin indicated PASS! All threads completed successfully. However I did notice the phone indicated an error during resizing. From the SM-986U boot menu, I then wiped the cache partition and rebooted. After reboot, my phone requested a PIN. However, the PIN I had set previously did not work. I then performed a factory reset in order to attempt to recover my previously-working phone. Now I receive a message indicating an unauthorized attempt was made to flash other firmware. It appears that I can allow the phone to connect to the internet and authenticate myself in order to correct this.

The entire reason I began this process was because I received notice that T-Mobile will push Android 11 to my phone within approximately 5 minutes after rebooting. Due to not-yet-ready status of Scoped Storage in Android 11, I want to wait to receive that update until those issues have been resolved. I want to flash an unlocked stock ROM to my phone (and then perhaps flash the TMO CSC back) in order to hold updates at the current level, until issues with Android 11 have been resolved.

@borijess (or anyone else who could advise), were you originally attempting to flash the U1 version of the stock ROM in hopes of unlocking from ATT? If so, what was your final solution... did you end with reverting back to the carrier-locked U version or did you find a way to unlock your N986U? I am in the process of downloading the U1 ROM now, in case flashing that one will solve my problem. Because that will take 8 hours... meanwhile I continue to research.
 
Last edited:

Note20Bckup

Member
Dec 29, 2020
8
2
How get back your carrier services if you changed your CSC code



Well with the help of these great XDA members I was able to restore my carrier services to my ATT 986U branded phone.

I made the mistake of messing with the CSC code without doing enough research. The mistake I made was using the procedure below on my 986U when it was meant for 986U1.

(I just pulled my SIM, entered *#272*MY_IMEI# and changed CSC from ATT to XAA. Rebooted phone without SIM and checked for update.)

Doing this made my phone lose all of its carrier services and I could not revert back. Luckily with the help of the XDA members they provided a tutorial on how to restore the ATT carrier services. It has been confirmed to work on Verizon and maybe other carriers. Follow the instructions below provided by @mlr_90.

1. First Flash your device with the U1 firmware found here using the patched Odin3_v3.13.3b: https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
2. Second make sure you flashe the AP,BP,CP and CSC found in the file. (Not the HOME_CSC)
3. Make sure to remove your sim card when you flash rom. Reinsert the sim card once phone is booted up and done with the initial setup. Once setup is done pop in your carrier sim card and you should get a message stating to reboot your phone. This will change your CSC code back to ATT/ATT/ATT from XAA/XAA/ATT.
4. Once your phone reboots confirm in the software information that your CSC is back to ATT/ATT/ATT
5. Now you can flash back to the U version firmware. Currenlty the latest is ATI6 found here https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
6. Flash using the U firmware using the instrucitons in step 2, but this time make sure your flash the HOME_CSC instead of the regular CSC.
7. Once this is completed flashing you should see your carrier logo during bootup and all the carrier services will be back on your phone.

Special thanks to
@mlr_90
@kangi26
@butchieboy
@warriorvibhu
@testrak

Question: Will changing your CSC to XAA or TMB, if you have an ATT branded device, allow you to receive updates from Samsung /T-Mobile only?

The reason I ask is because I bought an A10 UI 2.5-N20U from AT&T, which was SM-N986U (sim locked). I then flashed it to an A11 UI 3.0 SM-986U1 (sim unlocked), which changed it from ATT/ATT/ATT to TMB/TMB/ATT, since I am using T-Mobile now. I want to receive software updates direct from SAMSUNG, so the CSC can read TMB/TMB/XAA? Is this correct if I change CSC?
The version I flashed was: N986U1UEU1CTL4.
 
Last edited:

borijess

Senior Member
Jul 30, 2010
9,329
1,504
It is great to have such helpful people here on XDA! Thank you @borijess for posting this and thank you to all the members who helped provide the information for this solution!

I now have a problem (perhaps a different cause?) and I hope someone can help me to resolve this. I just flashed my new SM-986U (locked to TMO) to the USC (unlocked) version of the stock ROM N986USQS1BTK3 (from SAMMOBILE). Odin indicated PASS! All threads completed successfully. However I did notice the phone indicated an error during resizing. From the SM-986U boot menu, I then wiped the cache partition and rebooted. After reboot, my phone requested a PIN. However, the PIN I had set previously did not work. I then performed a factory reset in order to attempt to recover my previously-working phone. Now I receive a message indicating an unauthorized attempt was made to flash other firmware. It appears that I can allow the phone to connect to the internet and authenticate myself in order to correct this.

The entire reason I began this process was because I received notice that T-Mobile will push Android 11 to my phone within approximately 5 minutes after rebooting. Due to not-yet-ready status of Scoped Storage in Android 11, I want to wait to receive that update until those issues have been resolved. I want to flash an unlocked stock ROM to my phone (and then perhaps flash the TMO CSC back) in order to hold updates at the current level, until issues with Android 11 have been resolved.

@borijess (or anyone else who could advise), were you originally attempting to flash the U1 version of the stock ROM in hopes of unlocking from ATT? If so, what was your final solution... did you end with reverting back to the carrier-locked U version or did you find a way to unlock your N986U? I am in the process of downloading the U1 ROM now, in case flashing that one will solve my problem. Because that will take 8 hours... meanwhile I continue to research.
I ended up flashing back to stock ATT firmware. 986U.
 

naim1234

Senior Member
Oct 3, 2013
58
3
I have a galaxy z fold 2 that I flashed at&t csc on using Odin.
Now If I wanted to go back to U1 without wiping, would I do the sim dialer method ? Would that get me back to XAA/XAA/XAA?
 

miwang

New member
Mar 12, 2014
2
0
I bought a T-Mobile Note 20 Ultra, had it unlocked, and then inserted a Sprint SIM, now it's on Spring FOREVER...phone brand seems to be locked to Sprint and I have flashed T-Mobile rom but it didn't work...
 

tx_dbs_tx

Senior Member
Jan 19, 2009
2,024
8,714
Texas, USA
I bought a T-Mobile Note 20 Ultra, had it unlocked, and then inserted a Sprint SIM, now it's on Spring FOREVER...phone brand seems to be locked to Sprint and I have flashed T-Mobile rom but it didn't work...
You will neeed to follow the instructions in the OP.
But I'll help you.
#1. Reboot to recovery and do a factory reset and wipe cache then power OFF your phone.
#2 Remove sim card.
#3 Download and install Odin v3.13.1_3B_PatcheD.
#4 Download Frija Firmware Downloader from here
#5 Launch Frija and enter SM-N986U1 for model and XAA for CSC and download the latest Unlocked firmware for the Note 20 Ultra. Unzip it in a folder where you want your firmware.
#6 Launch Odin v3.13.1_3B_PatcheD and flash all of the firmware pieces and make sure you use the regular CSC and not CSC_Home
#7 Wait for it to complete successfully and the phone will reboot.
#8 Do NOT put your sim card back in your phone until AFTER you finish the initial phone setup wizard. Once that is complete then install your sim card and wait for a popup telling you to reboot your phone to setup your new carrier configs. Once your phone reboots it will setup your carrier/network configs just let it do it's thing.

From this point your phone will work on your carrier and there's really no need to flash the regular "U" firmware and doing so might screw things up and break your network settings again so try the carrier "U" firmware but be warned it may bug out on you like it did for me.

Good luck!
 
  • Like
Reactions: miwang

miwang

New member
Mar 12, 2014
2
0
You will neeed to follow the instructions in the OP.
But I'll help you.
#1. Reboot to recovery and do a factory reset and wipe cache then power OFF your phone.
#2 Remove sim card.
#3 Download and install Odin v3.13.1_3B_PatcheD.
#4 Download Frija Firmware Downloader from here
#5 Launch Frija and enter SM-N986U1 for model and XAA for CSC and download the latest Unlocked firmware for the Note 20 Ultra. Unzip it in a folder where you want your firmware.
#6 Launch Odin v3.13.1_3B_PatcheD and flash all of the firmware pieces and make sure you use the regular CSC and not CSC_Home
#7 Wait for it to complete successfully and the phone will reboot.
#8 Do NOT put your sim card back in your phone until AFTER you finish the initial phone setup wizard. Once that is complete then install your sim card and wait for a popup telling you to reboot your phone to setup your new carrier configs. Once your phone reboots it will setup your carrier/network configs just let it do it's thing.

From this point your phone will work on your carrier and there's really no need to flash the regular "U" firmware and doing so might screw things up and break your network settings again so try the carrier "U" firmware but be warned it may bug out on you like it did for me.

Good luck!
SOOOOOOO much appreciate it! You saved my axx!
I actually flashed the wrong ROM that day and just kept using it, and when I tried to flash it back to TMB, it got stuck on Odin, and with the tools you mentioned, it went through!
If I may bother to ask, will this ROM be good to update from system settings or each time I need to manually flash the latest firmware? And do you happen to know which ROM will unlock the esim feature?
Thanks again!!!!!!
 

tx_dbs_tx

Senior Member
Jan 19, 2009
2,024
8,714
Texas, USA
Follow THIS thread. I'm actually going to flash back the the T-Mobile carrier firmware.

If you're currently on the unlocked U1 firmware and want to switch to the carrier U firmware, factory reset your phone then power the phone off and remove the SIM card. Leave the SIM card out when flashing from U to U1 or U1 to U firmware or else the flash will fail. Download the latest TMB firmware using Frijay's windows application then unzip it and flash it using Odin3 v3.13.1_3B_PatcheD. Flash all parts of the firmware package including Userdata and the regular csc, not the home csc. Wait for the phone to boot and as soon as you can power off the phone and put your SIM card back in and power it back on. When the phone reboots you will get a popup for the new carrier SIM asking you to reboot the phone. Reboot and finish initial setup. Done.
 
Last edited:

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    How get back your carrier services if you changed your CSC code



    Well with the help of these great XDA members I was able to restore my carrier services to my ATT 986U branded phone.

    I made the mistake of messing with the CSC code without doing enough research. The mistake I made was using the procedure below on my 986U when it was meant for 986U1.

    (I just pulled my SIM, entered *#272*MY_IMEI# and changed CSC from ATT to XAA. Rebooted phone without SIM and checked for update.)

    Doing this made my phone lose all of its carrier services and I could not revert back. Luckily with the help of the XDA members they provided a tutorial on how to restore the ATT carrier services. It has been confirmed to work on Verizon and maybe other carriers. Follow the instructions below provided by @mlr_90.

    1. First Flash your device with the U1 firmware found here using the patched Odin3_v3.13.3b: https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
    2. Second make sure you flashe the AP,BP,CP and CSC found in the file. (Not the HOME_CSC)
    3. Make sure to remove your sim card when you flash rom. Reinsert the sim card once phone is booted up and done with the initial setup. Once setup is done pop in your carrier sim card and you should get a message stating to reboot your phone. This will change your CSC code back to ATT/ATT/ATT from XAA/XAA/ATT.
    4. Once your phone reboots confirm in the software information that your CSC is back to ATT/ATT/ATT
    5. Now you can flash back to the U version firmware. Currenlty the latest is ATI6 found here https://forum.xda-developers.com/galaxy-note-20-ultra/how-to/ota-ota-firmware-n986u-t4143833
    6. Flash using the U firmware using the instrucitons in step 2, but this time make sure your flash the HOME_CSC instead of the regular CSC.
    7. Once this is completed flashing you should see your carrier logo during bootup and all the carrier services will be back on your phone.

    Special thanks to
    @mlr_90
    @kangi26
    @butchieboy
    @warriorvibhu
    @testrak
    1
    I bought a T-Mobile Note 20 Ultra, had it unlocked, and then inserted a Sprint SIM, now it's on Spring FOREVER...phone brand seems to be locked to Sprint and I have flashed T-Mobile rom but it didn't work...
    You will neeed to follow the instructions in the OP.
    But I'll help you.
    #1. Reboot to recovery and do a factory reset and wipe cache then power OFF your phone.
    #2 Remove sim card.
    #3 Download and install Odin v3.13.1_3B_PatcheD.
    #4 Download Frija Firmware Downloader from here
    #5 Launch Frija and enter SM-N986U1 for model and XAA for CSC and download the latest Unlocked firmware for the Note 20 Ultra. Unzip it in a folder where you want your firmware.
    #6 Launch Odin v3.13.1_3B_PatcheD and flash all of the firmware pieces and make sure you use the regular CSC and not CSC_Home
    #7 Wait for it to complete successfully and the phone will reboot.
    #8 Do NOT put your sim card back in your phone until AFTER you finish the initial phone setup wizard. Once that is complete then install your sim card and wait for a popup telling you to reboot your phone to setup your new carrier configs. Once your phone reboots it will setup your carrier/network configs just let it do it's thing.

    From this point your phone will work on your carrier and there's really no need to flash the regular "U" firmware and doing so might screw things up and break your network settings again so try the carrier "U" firmware but be warned it may bug out on you like it did for me.

    Good luck!
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