This has been scratching my head for the last few months.
I think this has to do with Dolphin. When I have Dolphin running, the screen never goes into power save mode. But If I close it and wait ~15 minutes, the screen will go to sleep fine.
Reason why I’m asking, because I couldn’t find anything elsewhere either.
Sometimes, I leave it on for no reason. I’d just forget to close it. And with Dolphin running, it somehow stops the screens from going into sleep mode.
I don’t want to suspend the session. I want to turn off the screens after X minutes. So with a shake of the mouse, the screens turn back on.
Just a few minutes ago, my monitors went into safe mode. As it should.
I know it’s Dolphin, because it doesnt go to sleep when I have it open. If I leave the computer for ~20 minutes, the monitors never turn off. But without dolphin open, it does it fine.
I didn’t realize you had multiple monitors, since in your original post (as well as the thread title) you said “screen” and have since said “screens”. I tried on my PC (I only have one monitor) and it shut off as expected. Perhaps this is a multiple monitor issue as opposed to a Dolphin issue.
EDIT: Have you tried in both sessions, X and Wayland?
There is no solution, it seems. So report it to KDE or Arch.
Haven’t tested it myself, and it may not happen on my system since I have Dolphin installed, but I don’t have KDE.
It could well be a Dolphin + KDE issue.
You could test it yourself. Install a WM, like i3 or Openbox, log in, open Dolphin, and then leave it for a bit. Of course, with i3 or Openbox, you’d need to install the other packages that enable them to sleep. Check the Arch wiki for those.
Yeah, I know. But you don’t need to install KDE to install Dolphin. Also, when not using KDE, there are sometimes benefits to that, while also having drawbacks.
For instance, I get to use Dolphin (the best file manager known to man), and I don’t have to worry that every KDE-related update may have a bug that will bork my system.
On the flip side, right now I am forced to use a light theme for Dolphin because no matter which dark theme I use, the text is also dark, which means I can’t see anything but thumbnails and icons. This has been my issue for the last 3 weeks.