Unfortunately, I've started getting this issue just after getting a brand new PSU. It is a very strong PSU, 850w and gold certified. I have no idea what the problem is, but I have a feeling it could either be simply a loose HDMI cable or overheating/incorrect wiring with the graphics card. It does this randomly, and usually in the middle of a game. When this happens, the graphics card usually feels very hot to touch when I take off the side panel. For now, I leave the side panel off which may actually be causing the problem. I don't know if this is the proper section to post under but whatever.
Specs:
RX 590 8GB VRam
24 GB RAM
i5 7500 CPU
ASRock H110M-DGS Mobo
EVGA SuperNOVA 850 G2, 80+ GOLD 850W
Specs:
RX 590 8GB VRam
24 GB RAM
i5 7500 CPU
ASRock H110M-DGS Mobo
EVGA SuperNOVA 850 G2, 80+ GOLD 850W