[CONFIGURATION] DIsplay resolution not configurable

[joneall]

Since I updated my wife's computer, I can no longer select a display configuration. It's currently stuck on 1024x768 and refresh rate 76 Hz, quite unusable. If I click on either pull-down menu, there is only the one choice.

Running kernel version 5.4.0-59-generic with KDE plasma version 5.20.5. It works fine on my computer at the same level. My wife normally uses a config of 1200 to 1400 lines because of her AMD.

Thanks in advance for any suggestions.

[joneall]

Following up on a post elsewhere, I looked in .kde/share/apps but found nothing but one empty file xorg-session.log. Otoh, in .local/share/kscreen, there are some config files with the terminal characteristics in them. I edited them to 1080/1920 px and 60Hz on my own logon on the same machine, rebooted, and my login works fine now. So I copied the config file into my wife's .local/... and rebooted and her screen looks even worse.

I don't understand what is controlling the screen. Is it kscreen or sddm? Both are running.

How does the system know what screen size to use before anyone logs on?

My wife is not happy. So...

[joneall]

WHERE does plasma store screen defaults?

So I have found ~/.local/share/kscreen, which contains config files for the screen, including the dimensions and refresh rate. I deleted the directory on my and my wife's logins and rebooted. Afterwards, my login worked fine and I could modify the screen size in Screen Settings. But my wife's still was stuck on 1024x768.

I noticed that she was using the nvidia driver on her computer whereas I have nouveau on mine. So i deleted the nvidia driver. Now ... both our logons are stuck on 1024x768!

So my big question is the title of this post: Where in ... the world does plasma (or whatever) store the default screen values?

Meanwhile, I am quietly going mad looking for a solution. And my wife is not content...

[claydoh]

Nvidia drivers create an xorg.conf file, which normally is not required like it used to be back in The Day.
You might look to see if there is one (/etc/X11/xorg.conf).
You need to delete/move/rename (if it exists) that as it references driver stuff that has been removed, and is probably limiting resolution.

Check for the existence of the file /etc/modprobe.d/blacklist-nvidia-nouveau.conf, and delete that if it exists. This blacklists the nouveau driver from loading when the proprietary Nvidia drivers are installed. This would also be a cause for low resolutions as a lower level, basic 'vesa' driver may be in use.

running an apt autoremove might be useful to get rid of any possible stray nvidia packages.