I need help with fixing with my GPU. It is a Ryzen R9 390 Sapphire. The problem is that it isn't getting electricity and I can tell that by pressing the S button and it not displaying any sort of image. Currently I'm running my computer on a motherboard so I can still work on it. I have taken my GPU out and put it back again, I've taken the cables out and putting them back in again, it can't be a PSU issue because it worked for a long time before. One problem before it stopped working completely was the black screen issue.
Problem: GPU doesn't get electricity and it had had a black screen issue before
Things I've tried: Re-Installing previous drivers, cleaned out dust, taking the GPU out and putting it back in same for cables