iBook G4 won't start

Hello!

I've got a tricky iBook. I've got it for parts, but let's give it a try!

It hasn't got an optical drive, hard drive nor battery.

I put in a hard drive from my trustworthy Onyx TiBook.

Connected the power adapter, and pushed the power button.

No start up chime, display is black, but the HDD is started buzzing.

Pushed the power button again, but it didn't respond. Nothing had happened.

Okay, firewire cable in, connected the iBook to an intel iMac.

Target disk mode, maybe the display went wrong.

Nothing. It doesn't appear on the iMac.

So I tried the resets I know. Nothing.

Push the CapsLock button, the green LED ligts.

I tried to push the left side, if it is the famous chip problem. No.

So, is it a logic board problem?

Any solution is appreciated

Thanks!!!

Dave

Oh, I forgot it to mention, the microphone connector has broken off the logic board.