I just got an opened box Rx 5700xt Red Devil from Microcenter. After I put it in, the fans spinned for 3s and stopped, no light at all, then pc constantly crashed cause overheating. I used a 8pin to two 6+2 pins with corsair mx 1000 Psu. Could it be because of the conflicting old driver (was using nvidia gpu before)? Or is the card just dead on arrival?
The only thing I can help with is to let you know that this particular gpu (which I have as well) will save power by only having the fans spin under load. I've verified this with Powercolor, but apart from that, best of luck finding a solution, I'm struggling as well with mine.