does it do that when you attempt to boot from the Restore disks that came with the machine?
Can you ZAP the PRAM? Command + Option + P + R at the first chime and hold down for a further 2 chimes.
If there is any sort of warranty on this machine, I would call Apple and tell them all about it.
I doubt changing out things, RAM and Hard Drive, will have a deal of difference as the problem seems to be in the Firmware that controls how to boot.
I am having an odd pproblem with a MacBook Pro. When I boot, 95% of the time, the Apple sound will loop continuously and the Notebook will not boot. In every 10 tries, I will have a chance to get the machine to boot up into the OS, and after a little while the Display will start to flash randomly and the machine will freeze. only a force shutdown seems to bring you out the freeze, but then you can't always get back into the OS because of the looping Apple Startup sound.
It gets stuck at the exact same moment, right after the apple sound is finished, but loops.. So What I'm trying to say is that it doesn't get stuck at random moments, only just as the apple sound is finished playing, then it plays over, and over and over...
It's difficult running software to target the problem as there is almost no way of getting in, or booting from a Disk.
I have changed the RAM completely and still no difference.
Any advise would be appreciate just to narrow down this problem.
2.4GHz Core 2 Duo, 2GB RAM, 256MB VRAM, 160 GB 5400rpm