Well, like it says 
I am putting together a system from spare parts and I am trying to get this combination to display something. The RX 580 is fully functional, because I put it into another system running Windows 10 and it has no issues. The motherboard works because I put in a different GPU (same slot) and it has no issues booting up.
On the XFX/Asus combo I have reset the system BIOS, tried each video output from the GPU. There is only one PCI-E slot on the mobo so it is functional. In this combo, the power light on the GPU is blue and the fans spin.
Happy to provide other information if it will help. I've built a few systems before and this one has me stumped.
I am putting together a system from spare parts and I am trying to get this combination to display something. The RX 580 is fully functional, because I put it into another system running Windows 10 and it has no issues. The motherboard works because I put in a different GPU (same slot) and it has no issues booting up.
On the XFX/Asus combo I have reset the system BIOS, tried each video output from the GPU. There is only one PCI-E slot on the mobo so it is functional. In this combo, the power light on the GPU is blue and the fans spin.
Happy to provide other information if it will help. I've built a few systems before and this one has me stumped.