Help At&t samsung s6 flashing

[Staph Gavnar]

hi, i was trying to install TWRP on my At&t Samsung galaxy s6 SM-G920A after i rebooted the phone i had a notification which says "system software not authorized by AT&T has been found on your phone. Please turn off your phone and go to the nearest AT&T store for help". so i now tried to use Odin 3 to flash my phone and now faced with this:

ODIN MODE
PRODUCT NAME : SM-G920V
CURRENT BINARY : Custom
SYSTEM STATUS : Custom
REACTIVATION LOCK : OFF
Secure Download : Enabled
RP SWREV: B:4 K:3 S:3

Now i have tried to using SM-G920v to flash using Odin 3 and i had error:

sw rev. check fail. device: 4, binary:3

and i tried using SM-G920A still error

guys please i need your help
Thanks.

 

[Jfalls63]

If you are sure you have a 920A, AT&T locks the bootloader so you cannot install a custom recovery.
AT&T is stingy with their firmware and usually only release the first version that the phone originally sold with. Most of the time, downgrade is not possible. Sometimes you get lucky and there will be a leaked version.
Look here
https://forum.xda-developers.com/att-galaxy-s6/general/sm-g920a-nougat-7-0-1-stock-att-odin-t3811566

 

[Staph Gavnar]

initially before all that happened the android version was lollipop 5.1.1 ...thanks i will try and get back to you. so glad u responded

 

[Staph Gavnar]

Hi i tried the the site to get the firmware but it still fails

 

[joshi]

I have tried everything but there is no possibility to flash it! I received the same error! I'm sorry for you

 

[Jfalls63]

These are four part firmware files. You have to put each portion in it's slot in Odin.
BL
AP
CP
CSC
You need to use each slot, not just AP.

 

[Staph Gavnar]

i did that and same result ... what am i doing wrong ? thanks for your reply though.

 

[Jfalls63]

Are you absolutely positive of the model number?
In your first post, you have SM-G900V listed as Product Name, which is a Verizon branded S6.