Have you underclocked the GPU and memory for testing?
Reseated the card? (make sure the card is fully inserted if you havn't checked - seen this several times myself where my card was almost but not fully).
I would say the power supply is good since the 290 would take more power.
For black screens, try a lower refresh rate if using something above 60hz, if at 10bit try 8bit, RGB 4:4:4 full RGB to YCbCr 4:2:2 pixel format (if monitor supports). Just so many things can cause this but #1 most likely is a degraded DP cable. Yes it may work on one GPU and not the other - depending how sensitive and how much inspec it has to be between the video cards. Anyways reducing the bandwidth could help rule out the cable.
Bro, all my crashed happened with a Corsair CX750M, I have been using the computer without issues with a Corsair RX850M. I'm 100% positive your PSU will not work with your graphic card.
That's interesting since the 5700XT peak comes in at almost 100 watts less than the R9 290 Vapor-X I had before.
I'll monitor the power usage more closely and see if I can spot it doing anything weird, but I don't have a spare PSU of over 700 watts (and don't fancy having a unneeded 800 watt PSU sitting around doing nothing if it didn't fix it!)
I had that degraded cable issue with a dual-link DVI cable. Worked sometimes, other times black screen. Replaced with DP cable and that resolved it.
The card has actually now gone two whole days without a blue screen crash. Afraid that might be too little, too late though. It's fate is sealed.
Sorry, wasn't clear. I previously had cable issues as noko had suggested. I was agreeing that it can resolve a black screen problem.
My problem was a BSOD from videos on websites. I'm hoping it's resolved now by replacing the card with something that comes in a green box.
Since a new PSU would be around £100, I instead took a risk and bought a 2070 Super. As expected, it works fine and no more blue screen crashes. I'll return the 5700xt and enjoy the extra features I get for my £100 instead of just having an extra PSU that I couldn't use for anything.
If the 5700xt is peaking it's power usage well beyond what it's meant to, then it doesn't bode well for it's longevity. Best to return it now than months later when I'd have to prove the issue was there from new. I still think the issue is drivers, but they seem to be improving at glacial speed.
Thanks for the help though, good luck with yours. Hope it lasts you years.