My Galaxy Tab S2 8" running Marshmallow just died. It's two months old, has never been dropped or damaged. I had just charged it to 100% and began reading the newspaper download when the text disappeared as if a lght had been switched off. The screen was black, but the back and recent keys flickered on and off for a while. The large SAMSUNG sign began pulsing on the screen for a minute or so, then disappeared. No response to any of the keys. I cannot find anything in the manual to deal with the situation. What is likely to be the problem? And what do I do next?