This is from an old post, it would not let me post anything else on it so here i go. I already tried the apple + option + p + r keys. The computer just makes the start up noise again and again. Nothing happens at all. :( Any ideas? The powerbook G4 will not start up correctly. A grey screen appears and flashing in the middle of the screen is a folder, then the MAC face, and then a question mark. Also, there is a constant whirring noise within the laptop where disks are inserted yet there is no disk within the computer. How do I make the noise stop and how can i make my laptop reboot?

Hey, My knowledge of macs isn't all too great but from what i know, the flashy ? with the face means that the macs firmware cannot locate the OS. If there is no hard disk inserted like you might have suggested then this would indeed be the problem. I recommend giving it a hard drive and installing a decent OS, but then-again, maybe i mis-understood what you meant.

Sounds like the hard drive has failed. The PowerBook G4s are NOT that easy to disassemble, but I suppose you could try fixing the problem. First: Have you tried booting it from a CD/DVD, such as a Mac OS X install disc, the Apple Hardware Test disc, or one of the other discs which you should have? To boot from a disc, insert it and hold down the 'C' key. Then reboot the computer, and keep on holding the C key. Keep on holding until it recognizes the disc and starts booting successfully. What model of PowerBook G4 is it? Titanium? Aluminum? Display size? CPU speed?