5 Replies Latest reply: Feb 13, 2009 7:52 PM by Woodland Potter
Charles Underwood1 Level 1 Level 1 (5 points)
I powered off my iMac as it seemed to be stuck in a strange state.

I now have a problem restarting my iMac. Just getting the spinning gearwheel.

Have now started from the Installation Disc and the first thing it says is "Mac OS X cannot be installed on this computer".

I have run Disc Utility and Repair Disk reports that the hard disc is OK. When I try and restart again then the same thing occurs - just the spinning gearwheel.

If I take a look at the Installer Log then it says "Installation checks failed". There is no other information. I wonder what these checks are and if that might be a clue.

Any ideas anyone ?



iMac G4, Mac OS X (10.5)
  • Stukie Level 1 Level 1 (0 points)
    This happened to me once, turned out that Apple sent me the incorrect disk for my Macbook. I happened to wipe two hard drives simultaneously one night. My IMAC reloaded fine, not so much for the Book. Both my units were Refurb units and that's how the disk swap most likely occured. I would call Apple and get the correct disk, FYI they won't overnight a disk no matter what. I ultimately ended up having to go to the Store and have them reload my HD.
  • Charles Underwood1 Level 1 Level 1 (5 points)
    Thanks Stukie...

    Are there any other tools that I can use to try to fix the original problem i.e. the reason why the iMac won`t boot. Disc Utility reports that all is well and I have left it running for 24 hours now but just the grey screen and the spinning gear wheel. There must be some other corruption I guess.

    Any other ideas anyone ?


  • howwow Level 4 Level 4 (3,500 points)
    Hi Charles,

    _Try Zapping the PRam First_
    1. Start up your mac and hold down CommandShift+PR keys at the same time
    2. You will hear a softer startup chime
    3. Let it "restart" with the soft chime 3 times, then let go all keys

    See whether this will let your Mac boot up as normal

    If this doesn't work, then try the following:

    _Reset the SMC of your iMac_

    1.Read this to determine your iMac model:

    If yours is not the Intel Aluminum iMac, then do a search at the Apple/Support page and type "Reset SMC" to find the correct model and instructions

    Good luck and cheers
  • Charles Underwood1 Level 1 Level 1 (5 points)
    Many thanks - have zapped the pram and completely powered down as suggested but unfortunately there is no change.

  • Woodland Potter Level 1 Level 1 (20 points)

    So sorry about your iMac behaving like this.

    One day, I started my father's powerbook G4 and it did the same thing. Grey screen and endlessly running gear. Nothing seemed to work to get it to boot. We did a hardware test and repaired the disk using the install disk and Disk Utility. Even let Disk Warrior have a go at the thing and still nothing. Friend suggested that the hard drive had gone bad. Dad was going to take it in to Apple. Next time I came over, I asked Dad what he found out when he took it in and he said he didn't. He said he fixed it, himself, by simply re-installing the operating system. And it has worked great since.

    Hope this helps and you get your iMac back up and running fine.