Success! Ghosts run away! It was necessary to reset RAM in TEST MODE. That wasn't that easy as after i put BC 9500 in TM all controls lit up but after pressing key 7 all of them just blinked and no 1 on display appeared. I tried several times and no effect. So I tried to execute 7 by remote controller - no effect but strangely something was switched (volume controls lit up) and than I pressed longer key 7 and than finally 1 appeared on the display. The BC was reset and so far no self switches on.
Thank you all very much for help and support!!!
Max
PS I will try to get BL 5000 but offer is poor even on ebay.de.