2001 X5 with Nav TV Tape but CD has disapeared??

[steveddownunder]

My CD option has diappeared from my mode button - just TAPE & Radio now. The CD changer has power - the stacker seems to work. I believe I have DSP, there is a 3 wire plug in place and a 6 (I think) wire data cable going to the whatever (probably amplifier) under the dome. I am wondering how I can determine what is faulty. I also assume that when the item is unplugged the option disappears - but how soon does it reappear when you fix the problem - does the car need to go to 'sleep' or should the option come up on the head unit immediately - I need to know this before I try trouble shooting - it seems the data cable may be faulty, can I replace that with a coax cable - that does not seem to be there - maybe that is what is wrong? Steve.