Further update -- I tried the workaround you suggest; it doesn't work for me. The screen powers off and then immediately the backlight comes back on again. This is a problem that has also existed with earlier versions of KDE -- see e.g. https://bugs.kde.org/show_bug.cgi?id=174024
Further update -- I tried the workaround you suggest; it doesn't work for me. The screen powers off and then immediately the backlight comes back on again. This is a problem that has also existed with earlier versions of KDE -- see e.g. https:/ /bugs.kde. org/show_ bug.cgi? id=174024