connect it to an external monitor. a CRT or LCD. If you get an image on the external monitor then you know its a problem with the internal scree and not the motherboard. the screen problem could be an "inverter" or a "backlight" or the screen itself or the cable connections to the screen or the motherboard. In any case none of these things can be fixed by YOU. I just broke a laptop when I tried to replace the backlight. It's best to take it to a shop (a good one) and have them fix it. Get an estimate first - it may cost less to get another laptop.