This is in response to this post snd this bug report where user that was used to using TV as monitor in Lx 3 is now unable to do so in Lx 4. In this case user has visual difficulties seeing regular laptop screen so that is a major handicap to resolving the issue.
In my case I have Intel computers with Intel graphics. I tried this on an ASUS X550CA notebook. The notebook has 12GB RAM.
Booted the x86_64 ISO to ‘Live’ environment. Then plugged TV with HDMI cable. No display on TV. xrandr shows the TV as connected but does not show a default res for the TV. The file created in ~/.local/share/kscreen/ shows an entry for the Vizio TV but it shows it as:
and there is no resolution section in the file. However I think it is very important to note at this point that if I switch to a VT (Virtual Terminal) that is visible on the TV. So this is not hardware that does not work. The computer and TV are communicating. To me this definitely seems like a problem within Plasma desktop.
So I changed the “enabled”: false to “enabled”: true and restarted notebook from Virtual Terminal with ‘sudo systemctl restart sddm’ still no display on TV. Repeated this a number of times.
So that did not work.