Flash Verizon OEM software on AT&T S21 Ultra?

[mlbyanks11]

Hi all - Just wondering is this something that is possible? I have an AT&T s21 ultra with a Verizon Sim card in it. It is an AT&T branded device but like I said unlocked and has a Verizon sim card in it.

How do I go about flashing the OEM software onto it? I tried via Odin but it fails. Got the firmware from sammobile.com as per shown link below. Some guidance is appreciated. Please and thank you.

https://www.sammobile.com/samsung/g.../SM-G998U/VZW/download/G998USQU2AUB5/1496295/

 

[bxrider117]

re: Flash Verizon OEM software on AT&T S21 Ultra?

It can be done but the link that you loaded looks to be an older version of the Verizon software. Are you in the At&t version of this same software? To make it work you can not downgrade to an older software version. You need to be upgrading to similar or newer version.

 

[mlbyanks11]

re: Flash Verizon OEM software on AT&T S21 Ultra?

so where do I find it then? I figured that. any ideas?

 

[ironass]

re: Flash Verizon OEM software on AT&T S21 Ultra?

so where do I find it then? I figured that. any ideas?

These are the 5 updates so far for the G998U regional model on Verizon...

https://samfrew.com/model/SM-G998U/region/VZW/

 

[mlbyanks11]

re: Flash Verizon OEM software on AT&T S21 Ultra?

These are the 5 updates so far for the G998U regional model on Verizon...

https://samfrew.com/model/SM-G998U/region/VZW/

Thank you so much for that.

 

[mlbyanks11]

re: Flash Verizon OEM software on AT&T S21 Ultra?

So I flashed the firmware onto my s21 ultra and it did not work. still has AT&T branded software. followed instructions directly through odin.

 

[mlbyanks11]

re: Flash Verizon OEM software on AT&T S21 Ultra?

can anyone assist please?

 

[mlbyanks11]

re: Flash Verizon OEM software on AT&T S21 Ultra?

Where am i going wrong can someone please assist on this? I flashed the VZW OEM firmware to my phone and it still came up as AT&T once completed. Anyone?

 

[ironass]

Where am i going wrong can someone please assist on this? I flashed the VZW OEM firmware to my phone and it still came up as AT&T once completed. Anyone?

My only thought is that the AT&T and Verizon carrier models used to be famous for their own carrier mega locked down bootloaders that prevented flashing firmwares and rooting. See #1.6, here...

https://androidforums.com/threads/42-galaxy-s5-models-dummies-guide.892162/

This xda developers thread appears to confirm my initial thoughts that the AT&T carrier locked devices, (G998U, G996U and G991U), have an unlockable bootloader that prevents installing other firmwares. See...

https://forum.xda-developers.com/t/beware-new-at-t-s21-ultras.4258151/

It would not surprise me if the Verizon carrier, "U", models also were running their own carrier locked bootloaders as well. This would not affect the U.S.A. non carrier, "U1", variants.