If you were trying to run the installer DVD from the internal DVD drive, do you have an external DVD you can try ?

I assume you ran Disk Utility from the installer CD before beginning installation ...

I doubt if later MBs will fit properly, since the ports are prone to change in position and number from one model to the next. Also, the heat sinks for later CPUs might be radically different. It might be more affordable to just buy a used iMac; they're getting pretty cheap.

iMac 5,1 here ... replaced the HD and PSU so I know what you mean ...

Does the iMac boot OK in Target Disk mode ?

If so, you can try running the installer on another Mac and install to the iMac with a FireWire cable (if you have one ...).

Lastly, can you boot from a Lubuntu or Puppy Linux Live CD ? If so, maybe there's a problem with the installer disk (not necessarily the only thing wrong, though).

I should try the target mode (need the cable). Installer froze on me before I could format the new drive.

The internal DVD could certainly be part of the issue so any way to bypass it would help diagnose that. It is noisy (but they frequently are). What kills me is this mac does different things on different start ups. It would boot to Safe mode, now it won't. Won't boot to recovery mode. Sometimes it goes to a double cursor -- one frozen and one moving, sometime the second one is a beachball... etc.

Maybe I get the same model and keep this one for parts. The case is crazy clean and the display seems flawless.

In my search for options, I found lots of case mods like wood veneers (and matching wooden or bamboo keyboards), maybe I will do one of those on the grey iMac.

Thanks again for all the suggestions and info

During start-up and holding them down until the Mac chimes three times.

I also suspect the DVD drive. Do you have a friend with an external USB one? I have an external from LG that I got for about $30.00 that works great. I use it mostly w an old '08 MacBook Pro that has a misbehaving internal DVD drive.

and Snow Leopard is installing on the new 1Tb HD right now! 27 minutes to go.

Thanks much! I would swear I tried the PRAM zap 3 or 4 times when this whole thing started but I may not have done it right. Some guides say chimes twice, you said three times. I went for three and that worked. Btw, my keys to zap it were Cmd + Opt + P + R.

Not completely out of the woods yet but looking very good.

Dunno why three times just seems to really blow the cobwebs out for some reason.

Sorry about my confusion over key combo.

Cmd + Opt + P + R

I am so excited for you Glad you got that iMac going again!

did so in a white screen. It rebooted, played the music and stayed in a white screen. When booted again it froze in a blue screen. So it looks like a GPU or logic board issue. I think GPU would explain why it can show a logo screen (firmware) but never makes it to a desktop.

For about 4 days I was thinking about my next move on this -- sell it as is, buy another white Mac 24" (about $120 on ebay), try swapping the boards out. I was walking one of my dogs in an alley we seldom go into and there in the trash was an aluminum iMac! OEM cord, screen no cracked or anything. Carried it home, plugged it in and it booted to a flashing question mark folder so I'm thinking they just pulled the drive and threw it out.

So I have the drive that came out of my white Mac and I tear down the new machine. After a couple of screws I knew the machine had never been opened. There was blue stuff on some of the screws and everything was tight. Got the case open and it is full of dust in there. Original drive was in place so I swapped in my old drive and closed it up.

Booted right to a desktop I haven't seen in 2 years! PhotoShop, Illustrator, everything right there. It is a 20" but I am so glad to have a spare Mac again!

It's like some kind of computer karma kicked in and gave me another Mac.

Sounds like the Mac Gods are looking out for you. Sounds like a pretty decent upgrade as well!