I just for the 1st time tried to use the 6 disc magazine, I loaded the discs into the mag with the face up as noted, then slid the mag back in, and pushed the cd button on the command, I got a msg stating magazine empty, when I put a c.d. into the face of the command unit on the dash it plays just fine. I have had the car for a long time, yet never tried the 6 disc magazine before. It has never been used, I can't imagine there is anything wrong with the unit, I am guess the problem lies with the user, me, Can anyone help? By the way 2003 SL500
The culprit is probably the optical fiber plug ,under the CD player.
Remove the CD player from its place to have access to the plug. Disconnect it and connect again. I put a PU foam shim under the plug to maintain it in position. So far ,after 6 months it's still good. There are lots of info in the archives.