Have you tried using another input port on the graphics card. I know I'm having issues with my monitor and my graphic card's HDMI port. It will go blank occasionally for a few seconds (HDCP handshake issue?) and then be fine. Even on the desktop I can see the monitor refreshing weirdly.
I just switched the port, guess I'll see what happens.
Could be the monitor. I would suggest lowering resolution significantly, and seeing if it still happens.
My last monitor would black screen randomly while playing a different game, and only that game. Changing my resolution in-game would cause it to black screen, but it would save the resolution changes. Once I restarted, it would be fine.
I paid several hundred dollars for the monitor and gpu trying to get games to be good looking, I don't really want to drop resolution. My monitor is a 1920x1080, I don't see why that would be it.