I have a 520 from 12/2001 with a on-board navigation system which worked perfectly till few days ago.
The CD in the nav is pushed out from the player and the message displayed on the screen is only "No CD ....". I tried several CDs, even original ones, but no luck so far.
The red led on the nav unit in the back blinks continuosly and no sound of the cd being read is audible. So I was thinking of a mechanical problem with the reader.
However perhaps someone has some clue?

The sad part is that it seems that the replacement of the unit costs 1800 eur (only the spare part without labour) as it includes the cd player (only for the nav) and the full nav system unit.

If someone knows a bit more about the meaning of the red led or something about resetting the unit, I might have some further elements ..

Thanks