If it the same type of 5 CD changer as my Aiwa - Ie a large flat drawer with five spaces you could have the same problem as I had. The drawer moves in and out and is connected to the main body by a cable. Due to lots of flexing the cable became very damaged. Had it replaced with a much heavier duty one at a total cost of 20 UKP and it has worked fine since (2 years). I did need a sound systems expert to spot and repair it though.

Hope this helps

Cheers

Dave