mowaller

Q: My imac freezes on start-up if and when it reaches the grey screen with the Apple logo. After a few seconds the fan kicks in. I've tried 'safe boot' and resetting the SMU and PRAM, but no success.

My imac freezes on start-up if and when it reaches the grey screen with the Apple logo. After a few seconds the fan kicks in. I've tried 'safe boot' and resetting the SMU and PRAM, but no success.

imac G5, Mac OS X (10.4)

Posted on Apr 16, 2012 11:12 PM

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Q: My imac freezes on start-up if and when it reaches the grey screen with the Apple logo. After a few seconds the fan kicks in. I've ... more

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  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Apr 17, 2012 12:57 AM in response to mowaller
    Level 8 (39,326 points)
    Mac OS X
    Apr 17, 2012 12:57 AM in response to mowaller

    Just to confirm, your iMac is a "G5" (not Intel), and THIS is the procedure you used to reset the SMU

     

    http://support.apple.com/kb/HT1767

     

    and not the procedure for Intel iMacs.

     

    If you have the iMac connected to an old (or overcrowded) power strip, try connecting it directly to a wall outlet by itself.  Make sure no other cables (other than the power cord) are connected.

  • by mowaller,

    mowaller mowaller Apr 17, 2012 9:02 AM in response to Kenichi Watanabe
    Level 1 (0 points)
    Apr 17, 2012 9:02 AM in response to Kenichi Watanabe

    Thanks for your reply. Yes that was the procedure to set the SMU. What seems to be happening is the the fan kicks in as soon as the screen freezes. I have tried your suggestion for connecting to the wall socket as well.

  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Apr 17, 2012 10:12 AM in response to mowaller
    Level 8 (39,326 points)
    Mac OS X
    Apr 17, 2012 10:12 AM in response to mowaller

    If you press and hold the Option key during startup, do you get to the Startup Manager screen?

     

    If you insert your Mac OS X installation disc, and start up with the C key held down, are you able to start up from the optical driver and get to the Installer screen?

  • by mowaller,

    mowaller mowaller Apr 17, 2012 10:18 AM in response to mowaller
    Level 1 (0 points)
    Apr 17, 2012 10:18 AM in response to mowaller

    THanks will try that if I can locate the disk.

  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Apr 17, 2012 10:42 AM in response to mowaller
    Level 8 (39,326 points)
    Mac OS X
    Apr 17, 2012 10:42 AM in response to mowaller

    Actually, those were TWO separate things to try.  One is starting up with Option key held down, to get to Startup Manager.  Startup Manager is in ROM, so if that works, the iMac is getting passed its initial hardware startup test.

     

    If you are able to start up from your Mac OS X installation disc, then the iMac is generally working, but the problem might be with your iMac's hard drive (or possibly a problem with the installed system).

  • by mowaller,

    mowaller mowaller Apr 17, 2012 11:23 AM in response to Kenichi Watanabe
    Level 1 (0 points)
    Apr 17, 2012 11:23 AM in response to Kenichi Watanabe

    Thanks for that. Now the fan kicks in as soona the Blue screen with arrow pointing right and refresh icon appears. The fan is making an abnormally loud noise.

  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Apr 17, 2012 12:57 PM in response to mowaller
    Level 8 (39,326 points)
    Mac OS X
    Apr 17, 2012 12:57 PM in response to mowaller

    On that Startup Manager screen, if all you see are the arrow and refresh icon, there may be something wrong with your hard drive.  You should normally see the system installed on the internal drive as a startup choice, along with any other available system (such as a Mac OS X installation disc in the optical drive).

     

    Not sure about why the fan is being loud.  Odd fan behaviors is usually related the SMU.