I opened it up, and didn't see anything obvious. Called Orion, and they're replacing it with a refurb for $125, which for a $450-500 amp isn't a bad deal, so I'm gonna do that. Of course, mailing this hunk-of-heat-sink back to them isn't going to be cheap, but I don't have much of an option. Looks like i'm stuck with 30 hours of driving with two working speakers. At least I'll have a bit more trunk space with the subs out.

Matthew