I don't know what I'm looking at exactly in that picture... but unless he's cramming blunt objects in there or something, it's more likely that something shorted out or wiggled free. If that IS an Alpine, and it looks like the one I got years ago, then he had to have gotten an adapter for sure... maybe those can go out?
I haven't cleaned mine since I got it and it plays, it just skips now and then and then and then

. I heard you have to be careful when picking out the cleaner, though... any advice?
Oh yea, and you're playing the right kind of CD's right?