I use an old laptop (IBM TP T23) as a small server, but the problem is that it tends to get quite varm when the lid is closed. It's running Ubuntu 6.06 LTS, so I Fn + F3 doesn't work, and neither does this solution
. But I came across this thread: Ubuntu Forums - Force Monitor Turn On When You Open the Lid
That explains a problem that's a bit diffirent, but this works for my problem too.
First install vbetool:
sudo apt-get install vbetool
Now, whenever I want to turn off the screen on the laptop (which is usually whenever it has been restarted), all I have to do is to run this command:
sudo vbetool dpms off
Best of all, it works over ssh :o)