I'm having a problem that makes my laptop screen go black whenever I type, how can I solve this?

  Press and hold the Fn key and then hit the F key that has this screen icon once.
the screen should come back.
If it does not do not worry tap the F key again as usually this combination has more than two functions. 
This combination is used to transfer display to external device such as a monitor or a projector., or to extend the desktop etc. 
Remember Fn+ F key and with Dell it is usually F8 or the F4 key.

Maybe you need to update your need to update the graphics card driver or there is some hardwear problem.