Laptop won't turn on

Hello. I need help with understanding or how to get my laptop to work again. I have been always having problem with my laptop screen. While using it it will flash horizontal white lines across and at many times it will totally blink white pages where I would have to hit or adjust the screen to have it stop blinking. And a few weeks back I was streaming a video on the internet and it froze and won't turn back on. You turn it on, you can hear the laptop and stuff but the screen is black, it seems to be in sleep mode or something. It doesn't get pass that point. What may be the problem before I have an expert look at it?