i have a compaq presario 1200 laptop running on windows 2000. i have been having a problem with it. every so often when i start up the comp. the screen doesn't display anything (the back light is still on but it is just black). then like after a week it will work again. if i plug the laptop into another monitor then it works but then the laptop screen turns off completely (the back light turns off and its black). can anybody help me?