Sometimes after xubunutu screen is in hibernate mode the screen does not wake up. Open terminal ALT+CTRL+F1 (tty) Run: sleep 5 && xrandr -d :0 --output 'eDP-1' --primary --auto Then switch fast back to the graphic mode (ALT+CTRL+F7) wait a few seconds for the screen to wake up. 'eDP-1' is the name of your screen You can see connected screens running xrandr -d :0
Points regarding computing that I always forget - so I write them here to find them easily and maybe other could benefit too.