does my ibook g4 have a firmwair password?

Hey all I have two I book g4s that i bought from a school in Maine. They where MLTI laptops witch mean they where locked down for use in a school. When I turn one on the screen would flicker and shut off I tried fixing it and I made it worse can't boot ha ha ha so I started using a diffrent one a few days later when I turned it on it came up with the ? finder icon so I thought I will boot in to linux or some kind of live disk or maybe singal user mode and copy a file I NEED that was on the desktop but when i try to hold C to boot from cd or S for singal user mode i just get a grey screen insted of the ? finder I also can't get in to target disk mode I do hear the apple chime but don't see the apple logo what can I do? btw both I books have the same file in the same place I had a backup but I can't find it