This is one of my pet hates. I use the on off button when I don't want the monitor on. I have disabled kde power management and did that as soon as I installed kde5. This started happening a couple of days ago. Probably an update some where. I haven't timed how long it takes to do this but I can't see any settings anywhere to control it. I hadn't noticed that 5 doesn't seem to include a screen saver option but it behaves much like one except the screen goes close to black. It must be scanning otherwise my monitor would go into sleep mode of it's own accord. Anyone know of a way of preventing this. Not even sure it's down to kde. I tried xset -dpms and that has no effect. John -