The CD changer may suffer from an internal mechanical problem. Replacement of the faulty unit is generally required to correct this issue.Google+
Car Problem Reports
Mercedes-Benz CLK430 CD Changers May Suffer From Internal Mechanical Problems
Mercedes-Benz CLK430 Problem
Average Mileage: 93,333 mi (68,000 mi - 131,000 mi)
Visitor, 1999 Mercedes-Benz CLK430, 77,000 mi
CD player shows "No Magazine"
Visitor, 2003 Mercedes-Benz CLK430, 84,000 mi
WHEN TURN CAR ON CD CHANGER NOT FOUND
my 6 player cd states no mag as well. is that so because of a bad alternator?
Visitor, 2003 Mercedes-Benz CLK430, 90,000 mi
player skips cd's, indicates missing cd when it's not
Visitor, 2001 Mercedes-Benz CLK430, 131,000 mi
cd player stop working