Keyboard (on s laptop) fails to work in X/KDE on F8. How to resume it?

[Strong]

I have such problem: sometimes, occasionally my keyboard (on s laptop)
fails to work in X/KDE on F8. If I close the session (w/ mouse)- all is
fine again, but I would I would not to lose unsaved data each time. So,
while believing it will be fixed one, I would to know if there a way
how I can "reset" my keyboard yet while running session? Thanks in
advice.