So you've tried the reset button and no joy? This is the pioneer changer, right? To be honest what you're descibing is generally the beginning of the end for the CD changer and usually means opening the unit to retrieve your CDs. Have you tried completely disconnecting the unit? Even if out of the blue it springs back to life it will more than likely be a consistant problem. The only user caused problems i've encountered is people putting thier CDs in the magazine upside down and people using CD-R which can be considerably thicker than normal CDs.
I will check the schematic for you.
If i'm right then the CD changer fuse should be a 30 amp fuse in location 69 in the trunk.