I have the same problem with my build. I would recommend to first check your RAM. Grab a copy of Linux, they usually have a RAM tester on their ISO's. Burn it to a flash drive, boot up and check your RAM. Another thing that could be causing the problems could be a failing PSU. If you have another PSU laying around or in another PC. Try swapping and seeing if that solves your issue. It could also be a blue screen but they sometimes blackout if your graphics drivers are having problems. See if you can update those. (I know that's a repetitive response but I'm laying out your options.)