Disable screen power save, screen blanking, screensaver, screen saver, dpms
Unless I have a very specific reason to use a screensaver or screen power blanking then I disable this crap.
Edit /boot/cmdline.txt and add the following string to the beginning of the cmdline string (should all be on one line).
consoleblank=0 disable_splash=1 logo.nologo
Also remove any splash and quiet options.
You also need to disable some crap from inside X11, too. The xset -dpms shown below seems to be critical. These commands will disable it once for the current session. You need to find out where this stuff is configured to make this persistent across boots.
# this shows the current settings. xset q # Is 'xset s 0 0' redundant? # In theory only 'xset s off' and 'xset -dpms' should be necessary. xset s 0 0 xset s off xset -dpms