Grey Screen

[p1kef1sh]

I have a 24" iMac G5 intel. I tried to upgrade to Snow Leopard from Leopard and firstly I got an error message saying that I needed to clean the install disk. I did that and in fact changed the disk for another at the store. Since then I have done five clean installs and even managed to get the computer running until it had to close from a software update. Restarting I get to the grey screen with the Apple logo and the spinning wheel. After 5 minutes it shuts down and restarts, then the event is repeated. I have tried clearing the PRAM etc, but now I can't even boot to the Install disk. I'd be grateful for any guidance please.

[spinnerlys]

Do you have a PPC iMac (G5) or an x86 iMac (Intel), because Snow Leopard can only be installed on x86 Macs.

Have you tried this guide yet?

Mac doesn't boot (http://guides.macrumors.com/Mac_doesn%27t_boot)

[Hellhammer]

http://guides.macrumors.com/Mac_doesn%27t_boot

Your logic board might be dying :(

[OGDaniel]

Last summer the same thing happened to me with my 24" Intel iMac purchased in October 2007. The Geniuses' diagnosis was a dead hard drive. Just completely dead. Lost all will to live.

Hope you have Apple Care. I do and I thank God.

[p1kef1sh]

Thank you. I have tried most of the things mentioned in Hellhammer's post. I shall try them again.

[bbazzahh]

Boot up to startup manager holding down Option. If you cant see "Mac HDD" (Whaterver your hdd is named) then obviously the Hard Drive is gone

Spinning wheel and apple symbol normally needs to an error on the hard drive. If you are unable to boot to the installation disc then more than likely it is the hard drive.

If you somehow manage to boot to the installation disc, run a verify disc and check what the error messages are.

By all means check;
http://support.apple.com/kb/TS2990
http://support.apple.com/kb/TS2570

[p1kef1sh]

Boot up to startup manager holding down Option. If you cant see "Mac HDD" (Whaterver your hdd is named) then obviously the Hard Drive is gone

Spinning wheel and apple symbol normally needs to an error on the hard drive. If you are unable to boot to the installation disc then more than likely it is the hard drive.

If you somehow manage to boot to the installation disc, run a verify disc and check what the error messages are.

By all means check;
http://support.apple.com/kb/TS2990
http://support.apple.com/kb/TS2570

Thank you Thank you Thank you. I did as you suggested and managed to boot from the install disk. Once everything was loaded (after one false start) it worked! I managed to do a software update and a restart too. I am now too nervous to try upgrading to Snow Leopard for a few days! Many thanks again.