Just converted over from Mandriva to SUSE - install of 12.1 64-bit KDE was very easy!!

When I am watching a movie or streaming video, the screen will blank out after about 10 to 15 minutes. I have disabled the screen saver (set a long time to enable screen saver), so it is not that. I am thinking it a power saving feature that needs to be turned off. I am sure that this is a common problem, but was not able to find the solution with a search (probably not using the right terminology). How do I proceed?? I gather in Mandriva I needed to edit the /etc/X11/xorg.conf file, but switched over before trying that.

Thanks -- Roger