My 24" 3.06Ghz iMac will no longer fully boot. It constantly gives me the grey "Your machine needs to be restarted" half way through booting. At first I was able to boot into SuperUser mode and run an fsck which passed normally, but eventually after the constant rebooting fsk now reports:
Invalid node structure The volume Macintosh HD could not be verified completely
I have also tried booting to my Snow Leopard install DVD but that just brings up the grey "Your machine needs to be restarted" screen.
I assume now that my HD is toast (When using another Mac, I am unable to mount it in Target disk mode), but the inability to boot to the CD tells me there is something deeper at fault here. Is there any way that I can further diagnose the problem?