Security Error On My Samsung Galaxy S6

[newfieguy709]

Good afternoon folks, I am into a strange crisis here been at this now for like week and a half. I have a Samsung Galaxy S6 on a monthly Koodo plan which I have been using without a problem for approx 2 years one night I turned my phone off and went to bed wakes up next morning turns on my phone to use and I get this security error screen which says “This phone has been flashed with unauthorized software and is locked, call your mobile operator for additional support” then gives me a option to reboot. Right now I am paying for my monthly plan on my phone but I cannot use it I do not have any access to my plan to text or make a call all I can do now is connect to wifi in my house and use Facebook messenger. I really need help to get this problem fixed so I can use my phone on my monthly plan again’ any help would be appreciated

The exact model of my Samsung galaxy is SM-G920T
I noticed that my IMEI has changed from original to what it is supposed to be now too random # like 350000000000006

I have a strong feeling that my phone needs to be rooted which right now it is not because I checked with an app, I have no idea how to root my phone and flash it with the correct files

 

[B. Diddy]

Welcome to Android Central! Did you get this phone brand new or used? If it was used, the previous owner may have rooted it at some point and modified the firmware.

 

[newfieguy709]

Yes I purchased this one second hand but the guy assured me the phone was not lost or stolen or any money oweing which I did check before buying it from him and was good to go I've been using it for 2 years without a problem

 

[newfieguy709]

The phone was rooted and worked fine like I said for 2 years turned phone off one night because notifications was annoying me while trying to sleep wakes up next day turns on my phone to use and discovers the above problem as I mentioned

 

[B. Diddy]

Try reflashing the firmware using either Smart Switch (http://www.sammobile.com/forum/showthread.php?t=29914) or Odin (http://forums.androidcentral.com/am...w-flash-stock-rom-via-odin-new-interface.html).

 

[newfieguy709]

I have tried it but fails each time

 

[B. Diddy]

Both methods have failed?

 

[newfieguy709]

I'll retry it again and follow those instructions and report back

 

[newfieguy709]

just done exactly every step in the tutorial you have linked me too and it's not working, the problem with the tutorial is i should see and but i do not get this options at all

 

[B. Diddy]

What about Odin? I'm never quite sure how well Smart Switch works for this kind of thing.

 

[newfieguy709]

I have Odin downloaded and i have used it and downloaded the original firmware files for my model of my phone and serial i flashed it via odin to original firmware i downloaded from samsmobile it took a little while to flash the phone and once rebooted exact same error came up again and still cannot use the phone although after flashing with odin it stated the process passed and was successful but meanwhile still have same problem

 

[B. Diddy]

Sorry, not sure what to try next.:-\ Did you already try talking to your carrier? Not sure if they'll know what to do, but still worth checking.

 

[newfieguy709]

yes, I tried that as well all is good on their side of things so it's not them it's my phone, either hardware issue on motherboard or software, phoned the manufacturer as well samsung both canada and the u.s divisions, where the phone is a united states based phone t-mobile samsung Canada will not help and difrected me to the united states samung and they will not help becuase for authroized techincians working with samsung in the u.s need a address in the united states and be a resident the dont ship overseas as they put it to me if \i was to mail the phone to them