help My monitor is randomly going black?

[Arron]

I've had my PC since about June and I have a few problems with it, along with youtube deciding to systematically stutter in predictable patterns, my computer screen is now randomly going black at times. I know my monitor isn't turning off because it's not displaying the "hdmi" message, but it's also almost like it's just not displaying anything at all, like not "displaying black" but acting as if it IS turning off even though it shows no other signs of turning off and it only happens for a couple seconds. It doesn't happen often (it's happened twice now, once yesterday and once today). The only things that I have changed in the past few days that would cause this are fixing my ram to run at the advertized 3200mhz (it was running at 2133mhz before because I didn't have OC tuner turned on in Bios), I got a UPS system and started using it with my computer, and I switched where my headphones were plugged in to from the front of the PC to the back of my mother board. I'm still really new to computers as this is my first Desktop that I've ever built so sorry if I seem inept at this kind of thing, I just need help.