I finally reassembled the iMac today to make sure the display was working. Good news first, it seems to be working fine. Bad news, during the eighteen months or so since I last booted it up something got frazzled in the HDD and it isn't seeing the disk.

I'm thinking I'll take it back apart and try reseating the IDE connector another day just to be sure and then give installing a fresh copy of Sorbet Leopard a shot. Since I'm not planning on reusing the G4 for anything it's not a huge deal, but it would be neat to record a quick bit of video of the computer running under PPC power before I switch it over permanently.