Unwanted Display Blanking
For some time I noticed my systems blanking the monitor display exactly after 10 minutes of idle time. This includes all distros I have used recently.
I use the MATE desktop. After disabling the screen saver and power manager, the display still blanked at exactly 10 minutes. Temporarily testing with the Xfce desktop and the Fluxbox window manager provided the same exact 10 minute blanking.
I am not using an xorg.conf. No references to DPMS found in any local or default xorg.conf.d scripts.
Further digging revealed that the command
xset -dpms stopped the exact 10 minute cycle. The 10 minutes (600 seconds) is an X default setting.
I manually configured the MATE screen saver to 20 minutes and the power manager display sleep period to 30 minutes.
With the living room media player I disable screen savers and DPMS. When listening to music rather than watching videos, the TV is powered off manually and there is no need to tangle with those options.