My nextbook has been charging for over 24 hours now and it shows the red button and when I try to turn it on it only goes the the first screen then shuts off. Last night I checked it and it went from 40% to 32% to 29% as it was charging and the screen kept lighting up with the battery telling it was charging which it never did before. I can't even get on the main screen to see what percent it is on. Why is the nextbook not fully charging?