So my tablet won't turn on. I've charged it for endless hours. I thought maybe it was my charger that might have been the problem, so I bought 3 chargers so far. I've tried to charge it with those but it won't turn on still. I even tried to hold down the power button and the volume button (the '+' side) for a few seconds and it still won't work. I then tried to hold the power button and volume button (the '-' side) but it still wont work. I attempted it a few times and it won't work. What do I do?