CD Changer 'Magazine is Emply" message

Something similar happened to me recently. I have a '99 SLK with a six-CD changer. I was in the middle of listening to one, then decided to change to another, and pressed the button on the control panel that would do it; I got the "magazine is empty" message.

I pulled over when I had the chance, removed the magazine from the changer and reinserted it, all while the engine was running, and the changer worked fine. That was about a week ago, and I haven't had the problem since. (I hope that what you describe isn't the next step in a process of malfunctions!)

The Alpine unit (older model) on my wife's '95 E320 did the same thing - it was unable to load CDs. One time I was able to correct the problem by removing the unit, taking off the metal cover, and watching it attempt to load the CDs (I reconnected it after removal). I saw that the loading arm was jamming. I was able to push one of the gears with a narrow screw driver, re-grease the mechanism, and it worked fine for about another year or so. Then it failed again but this time the gears were locked solid so I ended up having to replace the unit.

I suggest you have the changer serviced by electronic shop... All cd changer work the same way so they know what to do.