If that doesn't work, you could just use xrandr to turn the screen on or off.
First, run $ xrandr | grep primary to find out the name of your laptop screen. (I'm assuming that your laptop screen is your primary display.) For me the output is $ xrandr | grep primary LVDS1 connected primary 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm so the name of my laptop screen is LVDS1. I can then turn it off with $ xrandr --output LVDS1 --off and on with $ xrandr --output LVDS1 --auto Then map these to convenient keyboard shortcuts.
signature.asc
Description: PGP signature
