6-CD changer fading out

I recently purchased a 2000 SES with 56,000 miles and the car is fantastic, except for the stock Ford/Clarion 6-CD changer in the trunk. The changer plays CDs just fine for awhile (~15 minutes), then gets a bit of hiss, which eventually (~ another 15 minutes) becomes so loud that the music is just barely audible.

Has anyone else had this problem or know of a fix? I've been told that this is a fairly common problem with these changers, but no one seems to know what to do about it short of pulling the unit and replacing it with aftermarket equipment. I not inclined to spend $250 though, if I can avoid it.

Cheers!