I was trying to figure out almost the same issue her for a Ubuntu 12.04 client which should run 24/7 without any blank or black screen. Maybe my way to fix things can help you, too:
First of all, I changed a line in /etc/default/grub, in order to switch off power management at all.
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=force"
After a reboot, the terminal command
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=off"
informed me that ACPI has been disabled.
dmesg | grep -i ACPI
Then I created a new file xset_off.sh in my home directory. Its content is
(Don't forget to make this file executable with
exec xset -dpms s 0 0 s noblank s noexpose s off
chmod +x ~/xset_off.sh
In order to have this script run everytime when your X window environment is launched, you can either add it to your autostart objects in the GUI desktop. Or you create a new file ~/.config/autostart/xset_off.sh.desktop.
Mine has the following content (autogenerated by the GUI desktop):
The next time when you have booted your system, a simple check of the xset parameters with should inform you that both Screen Saver and DPMS have successfully been switched off.
Comment=Screen Saver Off