How can I fix the cd player in my RCA RS-1285 home audio system?

This unit is a 5-disc changer which has simultaneous play & load. It will "read" a disc for about 5 seconds, then switch to each of the other discs and do the same thing, then it will show "No Disc" on the display, but there is no sound coming out. (The radio and the tape player do produce sound though, so I know it CAN). I got this from a friend who was throwing it away, thought I would try to fix it. The cd changer wouldn't close all the way, but I got that to work,( it opens and closes like magic now), and when I press a button for one of the discs, it does access the right disc.