Ibook g4 flashing question mark/folder on startup

Hi

Having some real problems with my G4 ibook 1.33ghz. I startup, it chimes and then keep getting a flashing icon and folder/question mark at the beginning. I know this is a problem with finding the startup disk. So this is what I have done:

Reset PRAM - no luck

Booting from installation disks holding down C - Runs through gets past flashing folder/question mark. Installation disk whirls up as if installing, but then goes to black screen.

Starting up holding down X to get the startup disk set up - no luck

Target disk mode - connectted my ibook to my G5, run my ibook as a firewire drive holding down T on startup. Shows up with firewire icon moving qround ibook screen. But doesn't show up on my G5 desktop! I have restarted the G5, check utilities, etc. But nothing, it does show up the installation disk that is in the drive of ibook. So there is definately communication, but the harddrive doesn't show from the ibook!

Ok so I found this link on al the posts I have read: Tried through linux to trick the startup disk. No luck!

http://www.bombich.com/mactips/openfirmware.html

Is this a harddrive problem or a motherboard? To me it must be the harddrive, but as it doesn't show up in target disk mode I am unsure.

Any suggestions on what to do?

I have searched the web and have tried all possible answers. If its just the harddrive, I will buy a new one. But is this more than the harddrive?

Thanks for any help

Zac

Zac,
Can you hear activity coming from the hard drive? I know it's very hard to hear regardless. But go into a quiet room and see if you hear spinning from the hard drive. Regardless it sounds like your laptop is not recognizing the hard drive. Since Powerbooks do not boot period if the motherboard is faulty, I would say you need a new hard drive which is extremely easy to replace on those.