I have a laptop with lubuntu 13.04
When given the shut down command, it exits the graphical interface, shows the lubuntu logo and then the screen goes black, but the computer never actually goes off until I press and hold the power button.
Is it possible to fix?
Try shutdown -h or shutdown -P, for halt or poweroff. It should turn off the machine completely. Apparently the -P option is safer (meaning it is more likely to cause the poweroff in different Linux distros), as it is more explicit and much less dependent on the implementation.
From the man page of shutdown:
-h Requests that the system be either halted or powered off after it has been brought down, with the choice as to which left up to the system.
-P Requests that the system be powered off after it has been brought down.
