Powerbook stuck on white screen; HDD OK?

So I've got a PB G4 that all of a sudden won't boot past the white screen. Sometimes it's blank, sometimes it has the apple and spinning icon. From what I've read, it's likely that something is wrong with the motherboard? At some point I'm going to bring it into the Genius Bar to get the bad news, but before then, I've got files on there that I need for work.

Does it sound like the HDD is still functioning? I'm about to order a 2.5" enclosure; this should work with the PB HDD, right? (never done much with Mac components, installing/removing, etc., just PC's).

Thanks for the help!
Brian

It sounds like it's most likely the logic board, though it's not common on Powerbooks.
Have you tried running disk utility to see what it comes up with?

Thanks for the tip. I ran disk utility last night. It took a while, and the screen kept having some message about "reserved file does not have data" or something. At the end, it said that one volume was repaired and one volume was not able to be repaired. Anything to be done with a volume that can't be repaired? I also tried the disk permissions, but it said that there was no volume with OS X (I think that's what the error message was).

Thanks!