Black screen

[ghi]

My laptop screen is black.
I have had this before, but can't remember what to do to bring the screen back to normal

 

[silverliquicity]

when you power on the laptop, does the screen flicker or does it stay off as if the laptop isnt powered on. Does it beep and do all the correct lights come on?

 

[alvine]

press function (fn) key and one of the f1 thru f12 keys to doggle your display between internal and external.

 

[ghi]

when you power on the laptop, does the screen flicker or does it stay off as if the laptop isnt powered on. Does it beep and do all the correct lights come on?

Scren stays black when turn on. Does not flicker.
However I can ear the computer running and it does the beeps.
Lights come on on the keyboard

 

[ghi]

press function (fn) key and one of the f1 thru f12 keys to doggle your display between internal and external.

Hi,
Tried the function keys to no avail.