Months ago I bought a used AMD card to replace my nvidia one. Weeks ago that card blew, so I bought a this time new AMD card which hasn't yet arrived. I provisionally reinstalled the old nvidia card but since the last working boot was with AMD all I get is an HDMI symbol on the monitor.
I can access the system from another one or from one of several Live/Rescue DVD's, how can I edit and what so that the nouveau driver will be used (for whatever card is in at the time)?
TIA
Chroot, blacklist the amdgpu kernel module, check if nouveau is blacklisted and if not, reboot. You're pretty much done. You can also follow this for proprietary nvidia drivers https://github.com/korvahannu/arch-nvidia-drivers-installation-guide