CD Changer hangs idrive

[nubeemer]

Recently purchased a 2004 E60 (CKD) with M-ASK business radio (no dvd or navi) with 6 cd changer in the glove box.CD changer didn't seem to be working, unscrewed it out of the glove box and found it unplugged - both fibre optics and power supply (as they are held together by a plastic plug) disconnected. Note that with this unplugged state, the idrive, radio etc. works fine (except for the bluetooth, which I believe has been bypassed by the previous owner)Upon plugging in the fibre optics and power supply to the CD changer, I am able to play CDs loaded into the CD changer but shortlived joy - thereafter, the idrive kept hanging (i.e. black screen) and music stops. It will return after some arbitrary amount of time, then go off again. So I keep the CD changer unplugged.Question:I understand the fibre optic forms the MOST ring. The removal of the cd changer would break the ring and prevent any communications running along this ring (hence why the bluetooth bypass is cheaper solution than replacing the telemetry control module - see other threads in this forum), which should therefore cause the idrive to hang. Why does the idrive only hang when the cd changer is plugged in BUT does not hang when you expect to after unplugging the cd changer?Any comment or advice is much appreciated.Regards,Jo