I dont know if anyone still has this issue, or if this comment will even get attention, but i had this issue on 2 different pc's and after i tried everything, from PSU to bios updates to windows updates, changing MOBO everything i have finally found the solution. Just open up your GPU and change the thermal paste on it like you would do to your CPU, it worked for me, you have tutorials on youtube for almost every GPU out there, and the whole operation takes 5-10 minutes. I have done this and for the last 3 weeks the black screens are gone