Thanks, will try this sound-store-1 or other ways and see....it should be something like that :).
I have the doc on the BC9000 including the additional doc for the 14 bit version cd mech as well as the 16 bit version as well as the conversion of the decoder board if a CDM4 is installed instead of a CDM2 (well, this is what i can make of it) so for sure both versions exist.
Now in any case, the CD is already fixed but...while repairing the faulty CDM2 with a spindle motor of a CDM4 i found out that the actual cd mechanism (the 'turntable' and laser unit) actually has a label CDM2 on it, which imlies that CDM2 and 4 laser/pickups are the same but the servo/decoders are different.
Anyway, it works...only the 'option' thing to solve :).