Please help, my screeen all of a sudden dims after 5 seconds, and then sleeps after another 5. This happens REGARDLESS of whether the battery is full or not, whether powersaving is on or not, and auto adjust screen brightness is on or not. I have tried rebooting, removing sim, fully draining battery, even hard rebooting, causing me to lose all my saved data. I am at wits end, my tablet is 3 months old, I need to know how to fix this. Please help.