I own the Kemper Amp for four years now but never had this problem before: Last night during a gig the display went dead (first time greenish look with strange sings, the other times blank white) and all the lights went off. The unit couldn't be shut down normally, only by pulling out the cord. I could change the presets via footpedal (Behringer FCB normally). After restarting the unit everytime things looked ok for around 10 minutes then the lights and display showed the same problem again.
Has anybody had the same problem and how can it be solved?