A black screen or a screen that fails to display could be a result of many things. Firstly, the laptop may have an automatic dimming setting which will cause screen to go black after a certain period of time. Try touching a key or the touchpad and see if the screen lights up again. Next, try and make sure that your laptop isn't dead and if it happens to be that then charge it and try again. If neither of the prior works, then the LCD Display is likely faulty, and will need to be replaced.