In my case, I think I have this resolved.
First I insured that my desktop computer settings were NEVER off but I might change that some future date when I trust win8.1-64 stability.
Then I made sure that my screen saver was set to some traditional scheme, nothing new that might be experimental to some.
Where I think I gained the most stability was ... of course ... dismissing one of those poorly designed apps (which does NOT imply exe and other REAL applications we have come to know since win3.1). In my case, I found that the new untrusted App "Photos" had commandeered some files (GIF) and the remainder were "owned" by a VERY stable viewer.
It was this awkward and often time consuming switch back-forth between viewers that actually cut off the signal to the monitor and put it to sleep! In the beginning, right after new computer setup, I finally learned to first see if the monitor power light was ON, for the impression was easily mistaken for an OS foul up.
The fix: choosing the more stable viewer for ALL files in the folder from which screen saver files are chosen and converting ALL those files to be opened by it = no more problems, no more flickers, smooth sailing ahead