My PowerBook G4, model A1138, won't start up. It chimes as if it were to start, but then it clicks over and over, and the screen remains black. There are no graphics or messages on the screen, but the start light comes on.

Before it broke, I was getting Kernal Panic messages pretty frequently, until it finally would not re-start.

The battery seems to work and it charges; meaning it's green or it turns red if I unplug it for a while.

I'm using the original power adapter, I'm the first and only owner. I tried starting it with and without the power adapter. I tried to start it in Target mode, but it didn't respond. It continued making the clicking "rotating" sound as if it were trying to start but can't.

I'm about to replace the hard drive, but would like to make sure that, that is the problem before investing the money. I took it to the Apple store but they wouldn't look at it because it's over 5 years old. However, the clerk suggested it was a bad hard drive even though he didn't look at it. He said if it were a bad logic board it wouldn't make any sound or even try to start at all.

I would appreciate any suggestions anyone might have. My PoweBook G4 has been great and I would like to keep it as a back up. Please help!