Bad subject line, perhaps? Problem is, on battery, kde is configured to dim display, and switch off after 2 min.

But when someone hits a key of mouse, the display is not increasing brightness. This used to work correctly on my lenovo laptop, but for the past couple of months no longer. I can manually turn the display brightness up with Fn-F6. The display is completely off, and for a long time I thought kde was just hung, but now I see the display is just turned down all the way.