Laptop Screen

[DevilsChild]

Hey, my laptop (Toshiba 1100 Satellite) has a broken screen, and ive been using a normal desktop screen with it for a while, but about one week ago when i plug the VGA cable into the back of the laptop and press Fn + F4 or whatever. the desktop screen goes blank and nothing comes up. I know it has tried to switch the image because i can barely see the image on my laptop and it goes completly black when i press Fn+F4.

Ive tried two screens so far and nothing... I know these screens work because im using them on my desktop computer as we speak.

Please Help lol
thanks

 

[Nitestick]

i have no idea what has happened to stop the desktop screens from working but if you search this forum there is a person that has posted tear down guides for toshiba laptops including how to replace screens.