I've been a happy Kemper owner for several years (non powered head). This afternoon all of the coloured LEDs for the stomp slots have turned off. There is no light behind the input/A/B/C/D/X/MOD. There are active effects in all of those slots. It does not alter whether or not the effect is engaged. The green delay LEDs are both lit and the output LED is also working.
I find it hard to believe that this is a hardware problem that these have all simultaneously gone wrong. I have tried turning the unit on and off a couple of times and changing rigs etc. but with no luck.