Broken laptop liquid display on sony vaio

Hi all, The screen on my sony laptop is broke and i cant see anything on it, i've plugged a monitor into it and pressed fn 6 but nothng happens, i cant see the laptop screen as the liquid display is smashed so i cant see if its telling me to do anything else, i've tried another laptop and this switches to the monitoras soon as the keys are pressed but mine wont , any help will be greatfully recieved..
shaun.