CD won't play past 50secs

[magpie]

The CD changer in my w215 won't play past 50secs. Up until that point the sound is fine then as it approaches about 47 secs it starts stuttering and then stops on 50.

After this point it won't play any other tracks on that CD if I skip forward or back a track however I can change CD but it still does the same on the other CD's.

I did by a lens cleaning CD but you have to forward it to track 2 and my changer won't play anything but the 1st 50secs of the 1st track of any CD.

Suggestions gratefully received!

Thanks