This is a problem that only happens on Fallout 4. Anywhere between 5 minutes to 4 hours my monitor will lose signal. I can't find a way to turn it back on aside from hard reset my computer. My GPU is a GTX 970 MSI. Its not an overheating issue using Afterburner so I am not sure whats going on. Is it unique to this game or what?

If not GPU, then could be PSU or motherboard slowly dying on you

It only happens in Fallout 4. I can play Final Fantasy XIV at max with 60 FPS for hours on end without an issue. Witcher 3 runs very well as well.

Do you got any BSOD, with an error name and number?

Nope. Screen goes black and I have to hard reset the computer. The event viewer tells me nothing as well. I can hear the game crashing it sounds like but I am not sure as the screen is black by the time I hear the sound. Its some kind of error.

What drivers are you using?

Just updated them with Geforce Experience so should be the latest ones.

OK, can you try those?

The game is still crashing.

Try disabling the Geforce Experience Software, it is a known cause of crashes with this game.

Same thing happened after shutting down Geforce Experience but I did have an odd thing occur. I tried to shut it down once and then the same problem occured where the monitor lost signal. The next time I shut it down without any issues.

I am also having this issue. Fallout 4 runs fine for some amount of time (anywhere up to a few hours) then it freezes and instantly goes black before presenting the "No HDMI signal" thing on my monitor. I am using an AMD Radeon R9 380 4Gb with the latest drivers. This also only happens in Fallout 4 for me and nothing else.

Edit: Since I am using an AMD card and getting this issue and you are getting it with an NVidia I am fairly certain that it is a problem with the game rather than our hardware. Hardware would make no sense for me anyway since my computer is only about 4 months old.