Screen may go blank after a few minutes of inactivity. Setting these values will disable this behaviour.

Go to Saleculator command shell (Ctrl+Alt+F1).

nano /etc/X11/openbox/autostart

Add the below values at the bottom of the file.

xset s off
xset -dpms
xset s noblank

Now save and exit.
Reboot the system to take the changes effect.