I have one of the earliest KPA's. Worked without any problem.
After 2 years and 1 month the LEDs died for no reason.
It was no big deal.
Achim (the one working in the repair department) repaired it really fast.
I got mine back within one week (shipping days within Germany included!).
I am pretty sure these LEDs will sooner or later die again.
My advice: Wait till you have too many dead LEDs to ignore, then send it in
An always prepare yourself that some may die again after repair (other users have reported this)
Now I am no longer in warranty. let's see what happens and what they will charge for a repair in the future.
In the meantime..rock on.