It's not as dire as the subject sounds. The tuner and player still work fine, but when I select aux, I get decreased volume (on that input) and static. I compared against my wife's player, to be sure.
I think I may have had an aux device feeding from the car power improperly grounded briefly one evening. I suspect therefore that I killed a capacitor or (less likely?) a fuse.
Sadly my spare player is still off visiting Europe, so I'm not going to send this one back just now... nor do I really want to do sSMT soldering to fix it, but I'm curious how I lost.