Darkened right panel on TV screen

So the Digihome 42/728 42” TV that I own has developed a fault, where it often shows this black darkened area on the right side of the screen. I’ve tested all the cables, channels etc and reset the tv and tried picture settings but the issue still remains. It’s out of warranty so If I need to open it up and check something, please let me know what I need to do thanks!