How to turn off screen with shortcut in Linux?

Try using

xset dpms force off

to force the screen to turn off.

I made a file called /home/me/bin/blank and made it executable chmod +x blank with the following in it:

#!/bin/bash
sleep 1; xset dpms force off

Then I set a shortcut in Gnome3 application "keyboard" (gnome-control-center keyboard) to run that script when I push CTRL+ALT+Q.

Man I love linux.

slock locks the screen gracefully.