Directv HR-24 repeatedly locked up at "Receiver Self-Check"... Already ordered replacement, but any final tips?

My HR-24 appears to have bit it after 8+ years of service. It was frozen on my DVR list earlier, I reset it, and it's never come back and has been stuck on "Receiver Self Check" on every reset attempt. Anyway, they're sending a receiver, but I'd still love to recover some recordings. Most of the responses to this question have been "replace your receiver," but any other tips? Any successes with leaving it completely unplugged for awhile or holding down some magic button combination?