Am I doing something wrong? I can't change my CSC

[shadowwisp1]

Hey guys, while I am not new to this, it has been several years.

I recently got a used unlocked Comcast/Xifinity S21. I have a T-mobile SIM card.

I tried flashing the rom to stock U1 which worked great but my signal is poor. While connected to Wi-Fi, the mobile networks/Network Operators in settings shows "T-mobile Wi-Fi Calling". But while I am not connected to Wi-Fi, the Network Operators shows Xfinity Mobile.

Under software information, it shows: CCT/CCT/CCT

How I can fix this? I made sure to not click the HOME_CSC when using ODIN, and I even did this twice. Should I just try the U firmware instead? Or was this because I left the USERDATA section blank in ODIN? (I used XAA, and then TMB a second time under Frija to download the files though).

Thank you for your help

 

[quadrun1]

Facing the same issue with my unlocked S21 from Xfinity Mobile - now using it on VZW but I can't get Wi-Fi calling to work at all... the toggle for it isn't even there! Haven't found a way to change the CSC.

It doesn't matter the SIM, even an AT&T SIM card displays as "Xfinity Mobile" on this phone!

 

[quadrun1]

Update: I was able to use SamKEY to change the CSC to VZW!

Instructions:

You need to buy one credit from a reseller on eBay and download the program on samkey.org

Then turn on Developer Options in Android, and from there, turn on USB Debugging.

Connect your phone to your PC, then run the SamKEY program.

Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!

During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.

As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?

I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.

 

[shadowwisp1]

Update: I was able to use SamKEY to change the CSC to VZW!

Instructions:

You need to buy one credit from a reseller on eBay and download the program on samkey.org

Then turn on Developer Options in Android, and from there, turn on USB Debugging.

Connect your phone to your PC, then run the SamKEY program.

Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!

During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.

As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?

I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.

Hey thanks for this!

I'm ready to change it but I get a warning using SamKey. Just wanted to see if you got the same warning or not:

"You phone has Special Carrier settings!

ITS NOT RECCOMENDED TO CHANGE CSC ON THIS MODEL.

Because Security area (SEC) may get "Relocked" and NO WAY TO UNLOCK IT again!!!

Are you sure YOU WANT TO CONTINUE CHANGE CSC?"



As you would imagine, just wanted to double check with you and see if you got this same warning or not.

Thanks! If not, I'll try doing a freshwipe and firmware and seeing if I get the same warning.

 

[shadowwisp1]

Update: I was able to use SamKEY to change the CSC to VZW!

Instructions:

You need to buy one credit from a reseller on eBay and download the program on samkey.org

Then turn on Developer Options in Android, and from there, turn on USB Debugging.

Connect your phone to your PC, then run the SamKEY program.

Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!

During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.

As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?

I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.

ignore my last post. I did a fresh wipe and tried again and didn't get that error. The CSC has now changed to TMB and already my signal has shot up. Thank you again so much!

 

[Dr-akbar]

ignore my last post. I did a fresh wipe and tried again and didn't get that error. The CSC has now changed to TMB and already my signal has shot up. Thank you again so much!

What if I didn't fresh install and continue changing the CSC with this warning? What would happen?