iMac gets grey screen on boot up

[musicpyrite]

Yesterday was just browsing the internet, listening to music, and chatting, and all of a sudden, my iMac completely froze up. I had to do a hard reboot by holding down the power button for 5 seconds.

When I tried to start it up again, the hard drive started to make this low chinking noise, and it spend about ~20 on the grey screen with the Apple logo and the spinning circular thing below it. Finally the the Apple logo went away, and was replaced by a folder the the smiling mac icon (like on the dock) and it stayed that way for about 0.5 hours.

I managed to boot off the hardware test DVD (it took another 20 minutes for it even to get to the test program) I ran it, it didn't pick up anything.

So then I go into the Disk Utility, and repair permissions (which took another 20 minutest) and i though it was interesting that it repaired the permissions on a file called:

/system/library/filesystems/hfs.hfs

I repaired permissions a second time, and it again repaired the hfs.hfs file.

I tried resetting holding down the option+apple+p+r and it wouldn't even get to the grey screen it just started to reboot again and again. Booting while holding the shift key didn't make any difference either.

So what do you think is wrong? I'm pretty sure I know what's wrong, I just want some other people's advice.

G4 iMac, 1GHz, 256 RAM, 15"

EDIT: tried booting it up in FireWire Target Disk mode with my dad's G3 400MHz iMac, no luck A message poped up saying you have inserted a volume Mac OS X cannot read, would you like to initialize it?

 

[musicpyrite]

Anyone?

I think I'm gonna just try and do a re-install, and hope I can scavenge some stuff.

 

[yellow]

If it takes forever on the spinny wheel thing (not the beachball), then it's struggling with the fsck preen that it does at boot. This calls for (at least) Single User Mode and "/sbin/fsck -f", so you can see what it complains about. Failing that, you should really be running Disk Warrior or TechToolPro on that boot drive, because that's where the problem most likely is..

I should add that a "low chinking noise" is not a good thing. It could be a head crashing in the disk, which means it's on it's way to being unrecoverable.

 

[musicpyrite]

"/sbin/fsck -f" didn't work because when I hold the apple+s keys on startup, there is a brief moment when the screen shows up with a question mark, and a folder. From then, it just continues to get the grey apple icon, and just stays that way.

As far as repairing it, I do have TechTool Pro I'll see what I can do with that.