The MP3 player of my Corolla in not working!!!?

Hi.

I have a 2003 Corolla in India. The main problem is with the MP3 player. The player is dash board mounted and is a 6 CD changer, however, the same is not playing the CD's and MP3 although I have checked with new scratch free cd's as well.

The same is playing one or two mps and not all of them. Anyone can please help me with this. I am not sure if I have done something wrong with the settings. Need urgent help.

Regards,
Chirag