I'm a bit stumped with this one. I recently picked up a 390 to upgrade from my 760, swapped it in and got everything working fine in Windows.
When I first booted into my Antergos/Arch install, I was able to log in, then started getting a lovely graphical glitch show after a minute or two in both XFCE and the tty consoles. Since I didn't do any driver configuration before installing it (I'm an idiot for that, I know) I figured it was because I didn't have any AMD drivers.
After hooking up my Intel graphics, booting, then plugging in a second monitor into the 390, I was able to see clearly again to get to work with troubleshooting. I installed the open source AMD drivers, then uninstalled the open-source NVIDIA drivers I was using.
One reboot later, everything was alright. That is until I switched on the second monitor in XFCE, having both run off the 390. A few seconds later, I received another rendition of my lovely glitch show.
Every time I boot now, I'm greeted with a black screen and can't even get a console up.
tl;dr - Switched from green to red, switched graphics drivers, can't see a damn thing in Antergos/Arch
Any ideas on where I should go from here?