24" Aluminum iMac Won't Start

I have a 24" Aluminum iMac that just won't boot up. When I turn it on it makes the deep noise it always does, and then it stays at the grey screen without ever showing the dark grey apple.

I tried to boot from my leopard disk by holding down 'C' key at bootup and this doesn't work either.

The only thing I have plugged in is an apple keyboard and mouse and power cord.

Are there any other things I can do short of taking it to an apple store?

Thanks for any help.

Try resetting the PRAM and NVRAM. See the following Apple KB article: Link

Afterward, try rebooting from your Leopard disk again. If you can successfully boot with the Leopard DVD, run the Apple Hardware Test.

Regards.

I reset the PRAM and NVRAM from the link you posted.

I tried again to boot from the CD. It didn't work.

I just tried bootimg in safe mode with the shift key held down and it got a little farther this time. its sitting on the grey screen with the grey apple right now reading the leopard DVD for quite some time now...

Is there anything I can do at this screen?

This sounds very similar to what happened to my iMac just a couple of weeks ago. Tried everything there was to try. Nothing worked. Eventually called Applecare, who came and took it away. Faulty HDD. Asked for my old HDD back to recover data. Returned old HDD back to Apple. They installed new HDD. Quickly bought 1TB external and setup Time Machine

If you have another Mac, try Target Disk Mode. See if you can retrieve you files first.