IBook G4 won't start up, blue screen death! HELP!

Question

I have an iBook G4 (1.2ghz). It has a new hard drive (5 months old), 2 gigs of ram (5 months old), and a new battery (2 months old). I was checking some baseball scores today, and everything froze, as if the hard drive had died. I tried to reboot, and it got stuck at a blue screen. I tried to reboot 4-5 times, and once it worked! I tried running my backup software, and it froze, without backing up my files. Since then, I have:
zapped the pram,
tried to start from a CD
tried to start up in safe mode
nothing gets me past the blue screen of death. I can't even fathom why it won't start from a CD. Is my computer dead? is the hard drive dead? what is let to do?

Answer 1

for those who come across this - and have similar issues - i have an ibook g4 - 14". I used the shim method described by http://www.coreyarnold.org/ibook/ . While he used this method on a 12", I used it on a 14", and it seems to have worked. The computer has been up and running for nearly 4 hours and everything has been backed up. I used 2 3/4" rubber gripping pads purchased at true value for less than $2. The tools cost me $25 from ifixit.com. Beats a reball, and certainly beats a $300 logic board replacement (not including labor!).