Good news! I got partly success with this issue. Now volume upand down is workiing in KDE, but still NOT screen brightness.
What did I do? I first created a new user and then could see, volume is working. After that I moved some directories from my old user away. First ~/.local - no success. then ~/.kde - no success last ~/.config - success. Now I knew, some config is making trouble. So moved the most suspicous away: Anything with "keyb" in its name, or "kbd" - no success. Then all files below ~/.config - success Now moved one after another back. And at last, I found it is kdeglobalshortcutsrc Strange, this was the one I moved away at first, but got no success. Short before long: My efforts resulted in half success, as brightness can stoill not be controlled and in XFCE still volume control not working (so I guess, same issue with some config). After all the work, I believe, that some configs still got settings from my former notebook which was a Lenovo T520. As I put the harddrive into this one (DELL Latiude 5400), some config files are not overwritten since creation. You can say: delete ~/.config and ~/.local and set everything new. Yes, I could do this, but this is a lot(!) of work and I want to avoid it. So still hints are welcome and I suppose, we will all learn of it, don't we? Have fun! Best Hans
