Is it possible the tablet is not charging and you are dealing with a dead battery. when you plug it in to the charger does it show any lights or display on the screen . if not you may need a new charge cable or a complete charger. If its charging properly then try holding the power button down till you get some sort of response. if that doesn't work try holding the power button and the volume down button till you get the android logo then navigate down in the menu to boot normally and select that.