The CD4 decoder board was available as an option for 4002, but it was pretty rare. I guess there's a place for the switch on all 4002 chassi? If you can find the type number on your player, it should confirm if you have an original 4002. Even if you don't need the CD4 function - it's hard and/or expensive to find a cartridge that can do that nowadays, let alone CD4 records that haven't been destroyed - it doubles as an excellent quality RIAA preamp. Should be even better once you upgrade the caps on the board:
http://forum.beoworld.org/forums/thread/66387.aspx
...but I've yet to do this on my 6000.
I have a theory on the fuse problem, but it might be far fetched. The solenoid works pretty much like the one in car starter motors, it takes a lot of current to pull and then the circuit drops to a low current "hold" state while the tone arm is down to keep the current requirements sensible. I don't have the schematics here with me now, but I seem to recall that the solenoid had a contact (just like a relay) which controlled the hold current. Maybe you have a bad contact or loose wire/solder joint somewhere, and the solenoid is being pulled with the higher current all the time and that blows the fuse.