PowerPC :: 20" IMac G5 (1.8ghz Single Core) - Not Booting From DVD?

I have put a brand new hard drive in the machine. I took off the plastic bezel to the power cord, to make sure it's plugging in all the way. I turned the computer on while watching the LED's on the logic board. All 3 stayed on, and the 4th never came on.

I have unplugged it, left it unplugged for a few minutes, plugged the cord back in while holding the power, then turned it on (forgot what that was supposed to accomplish). No change.

I have reset the PVRAM (or whatever) 3 times in a row by holding command-option-p-r until I heard 3 chimes after the initial boot. No change.

I can get into open firmware, but have no idea what I could even try in there (other than ejecting the DVD).

I hold down "C" while booting, it chimes, it goes to a blank grey background, then proceeds on to the white screen with the apple. It sits there for a few seconds, then starts spinning the circle for a while, then shuts down. I hear the optical drive spin up, but it does nothing.