THanks for all the help! It did turn out to be a loose connection. I didn't have to open the top of the computer. It was on the part of the board by the hard drive, but on the bottom of the laptop that I had open for the DC in adapter. I'm attaching an image in case anyone else has the same problem.
My ibook G4 is having the same issue. Tried resetting PRAM- no good. Tried shift key and got kernel info across the screen w/the end message being: "we're just hanging out here" Is the HD dead? Sometimes it shows up in Disk Utility w/no size or specs, sometimes not at all. Any other ideas?
The toothpick thing didn't work for me, but I did the step by step repair and it worked fine. New adapter charges the battery just fine, but now my hard drive is acting weird. Booted up once in 20 tries. The Tiger disk sees something on the ATA sometimes, but no drive size or anything. Any ideas what I messed up?