You're using Gnome, not Genome. :-D
Something to try would be this command in a terminal:
That will disable dpms which is what controls power management in X with respect to your monitor.
If you want to get your hands dirty, the best way to disable it would be to edit /etc/X11/XF86Config-4 (or XF86Config).
You'll be looking for a section like this (taken from mine in Slack 9.1):
# HorizSync is in kHz unless units are specified.
# HorizSync may be a comma separated list of discrete values, or a
# comma separated list of ranges of values.
# NOTE: THE VALUES HERE ARE EXAMPLES ONLY. REFER TO YOUR MONITOR'S
# USER MANUAL FOR THE CORRECT NUMBERS.
# DisplaySize 320 255
HorizSync 24.0 - 80.0
VertRefresh 50.0 - 75.0
Option "MonitorLayout" "TDMS"
Option "DDCMode" "on"
You'll notice the line that says Option "dpms"
You can comment that option out by simply entering a hash # in front of it, as you see is the prefix before the other "comments" within that section above.
You may also see some options as far as times for DPMS actions, like standby, shutoff, etc.
You can comment those out too. Save the file and restart your X session and it should take effect.
May be best to do that editing while in command line mode, as Gnome or another app may be saving the XF86Config file on exit, and you'd lose your changes. Then when it happens again, you'll be thinking "Why didn't it work???".