On my relatively new Asus tablet,(I got it on the first of April), the screen keeps flickering to Gray with different coloured bars across it. I've reset this tablet, so I know that it's not a virus. The screen seems to flick randomly, not just when I move it or connect it to my charger. It does flick when I put in my headphones and connect the keyboard. Why is this happening, what type of problem is this and how can I fix it?