Samsung Galaxy SM-T337A (Samsung Galaxy Tab 4) failed root resulting in device being bricked. Any help?

[TJS_Omega86]

A family member of mine bricked his Samsung Galaxy Tab 4 bricked his Samsung Galaxy Tab 4 trying to Root it, and now whenever it is powered on it gives the message " System Software not authorized by At&t has been found on your tablet. Please turn off your tablet and go to the nearest At&t store for help." Of course At&t will not help with this issue, so I am headed down what I am sure is a long path to try to recover this thing. Un-rooting Android devices is not my specialty, so I was wondering if anyone here at Tom's Hardware may have an idea of what course of action to take with this and maybe some links to software I will need. Any help is appreciated! Thank you in advance!

BUMP

 

[hang-the-9]

Have you tried a factory rest using the buttons? If yes, then do a web search for a stock ROM for the tablet model, you will need to flash that to the device using a computer.