How can I fix the CD changer on my 1997 Ford Explorer?

I have the 6 CD changer in the center console. I removed the magazine & changed 1 of the 6 CDs. After re-installing the magazine I attempted to click up to CD #6 but after CD # 3 the dash indicator flashed no CD. Now it will not advance to any other CD & will not eject the magazine.
Please help!

Wes
June 2010