I recently got a PowerBook 3400 that would chime, then chirp and make some pretty crazy siren type sounds. The sound would go away and the screen would light up if I disconnected the hard drive. I assumed not enough power was getting to the HDD, so recapped the DC-board and MLB (just three caps) but it made no difference. I installed another hard drive and it booted just fine. I then gave the original drive a good whack on a desk and reinstalled it. It then booted just fine. So something must have been stuck inside the old drive.
Video of the original symptom here.
Video of the original symptom here.