I hate to discard my old Mac Pro, but I don't know what to do. The screen is either not coming on or I get black and white vertical lines. MY keyboard is not responding. I did test the keyboard on my macbook and it works. When I turn the Mac Pro on it takes a few seconds and then you hear the sound of it being boot up, but the screen comes out dark or vertical lines. Is there anything I can do to save my Mac?