I also changed from multiple to single rail, problem still there
Next steps I took are the following, the problem did not go away;
1.Installed my old PSU HX620
2. Installed again my stock cooler
After doing above, I though this might not be a hardware issue so I re installed my windows, did not install any motherboard utilities just the drivers, clean install of latest Radeon software (19.5.2) but still i encountered the errors at two instances;
1. while installing AutoCAD
2. while using powerpoint (inserting a picture)
for the GPU i did the following;
1. adjusted the boost switch, this reduces the boost clock to 1545 from 1560
2.in wattman profile i reduced maximum clock to 1390 and increased power limit to 50%
I am currently downloading a game to check if error will happen while gaming
The RX590 requires a minimum PSU wattage of 600 watts plus you also have a Rzyen with a TDP Wattage of 95 with the AIO CPU Cooler. But your high quality PSU should be sufficient to run your computer without any power issues.
Have you tried to using AMD Wattman to configure the RX590 Power as per this AMD Thread: https://community.amd.com/message/2915523?commentID=2915523#comment-2915523?q=rx590%20wattman
If you set the Power Limit to 50 in Wattman and set the GPU Fan curve to be aggressive and you continue to crash, I would suggest Stress testing the GPU card to see what data is showing when it crashes such as temperature, voltages, etc.
I personally like using OCCT since it stress tests the CPU, GPU, and PSU. But there are others that you may prefer or believe are better.