venue 8 black screen after android logo

I have a venue 8 model 3840 and when i turn it on I see the android words on the screen but instead of taking me to the main screen with the icons it goes to a black screen that has a white line at the bottom that flashes. It was working perfectly fine and it started doing this. I called customer service spoke to someone that transferred me to another department but I waited 17 minutes in line and no one answered me. I need help!!!