Inspiron 8500 No video

My laptop suddenly stopped working. The display showed a lot of colors and shut off. I had previous heat problems so I thought they had resurfaced so I waited the appropiate time and turned it back on . I got the post screen and then it went off again. Now when I turn it on I don’t get any video.I start in diagnostic mode fn + power and I get off – flashing – on. Do I need another video card