Anthony, I have just recently fixed a similar issue that was NOT showing up on my GTX 960 GPU - even under the heaviest load it's ever underwent on Firestrike benchmarks and the like - but it would randomly black screen and the sound would still play from the speakers and I could hear my computing responds to mouse/keyboard clicks.
I first replaced my PSU, no change whatsoever, so I ran an old GT 640 inside of the PC for a month straight with no issues, once I was convinced it was my GPU I bought a GTX 1660 TI and the problem hasn't occurred since taking out the GTX 960.
A good way to see if you are experiencing something similar - I find blank displays are usually linked to DWM.exe crashing due to one reason or another, it can be anything from bad drivers to a bad PSU to a bad GPU (like my case)
Type Event Viewer in Windows search, open it up, on the left side click on "Windows Logs" then in the middle window click "Application" then on the right hand bar "Filter Current Log" open this up and filter by "Error and Critical" only.
What you're looking for is an error that matches the time your PC crashes (look at timestamp on the error and the current PC time, should only be a few minutes prior if the crash just occurred.)
Mine was a KERNELBASE.dll error which I'm guessing is something tied to the GPU that was failing - yours may throw a different error - hopefully a nvidia.dll file error that can be easily fixed, otherwise you may have a similar hardware issue to mine.
EDIT: Would also like to note that the PC almost NEVER crashed under idle, it even ran for 2 days straight with no errors from the faulty GTX 960 before it started throwing up errors everywhere again, so the issue is extremely sporadic and I don't think it's something that can necessarily be reproduced unless it's specifically tied to one thing in your PC which I don't believe it is.
EDIT: Also, would like to point out that I was having major issues with DirectX before I got the GTX 1660 TI and even using DDU didn't solve it, I used DDU last night and did a fresh install of my NVIDIA drivers for the GTX 1660 TI and it fixed all my DirectX errors too.