I have a new box I’ve recently built with a core i9 CPU, a Z390 motherboard, and a K4200. After figuring out how to get nomodeset to take effect, I was eventually able to get things working but only with 18.04. Neither a direct installation of 18.10, nor an upgrade of 18.04 to 18.10 (after installing 415.18 drivers) yielded success. I’m typing this from 18.04 running 415.18 and things seem to work fine, but not so with 18.10.
I can switch to a TTY (Ctrl Alt-F1) at boot up to get a shell prompt, but no graphics appear. What might I do to debug this from the TTY shell?