Audi CD changer error

The factory fitted glovebox CD changer in my 2003 B6 S4 (with Navi Plus) has stopped working.
If you try to select a CD, the changer repeatedly tries to load
each disk in turn, one after the other. At the same time, the disc lights on the changer are trying to mimic the the bridge of the USS Enterprise (sp?)! Numbers 1, 3, & 5 light up together, then 2, 4, & 6 together. This repeats for quite a few cycles, and then they light up individually in sequence, one after the other - 1 > 2 > 3 > 4 > 5 > 6 - again repeating for a few cycles, before eventually stopping.
None of the buttons on the changer respond to pushes.
The Navi display screen top half reads "check magazine" whilst it is cycling through the discs, and then "error" after it has finished. The bottom half reads "no cd 1" "no cd 2" etc all the time.
I have pulled the radio fuse for a while, which also kills the CD changer, but the problem returns.
Any ideas anyone?
'06 Golf GTI 2.0T FSI, '03 Audi S4 v8, '99 Astra 1.8 Sport
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Site Timeline is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.