4 Replies Latest reply: Jun 23, 2012 9:54 AM by rccharles
finfandan Level 1 (0 points)

G5 imac wont restart

  • Kenichi Watanabe Level 7 (32,842 points)

    "Restart" normally means the Mac is already running, and you select Restart from the Apple menu.  Is that what you mean?  Is it "hanging" while trying to log off and restart?

     

    Or, do you mean it won't power up (from being off), or that it powers up but does not "boot"?

  • finfandan Level 1 (0 points)

    It powers up but wont boot. I've tried powering multiple times, even unpluging it completely. also I've put in the original disk at start up to reformat it if I had to but nothing.

  • rccharles Level 5 (7,574 points)

    Try holding down the option key then power on. This brings up the startup manager. Click on your hd. Click on right arrow key.

     

     

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    worth a try:

     

    Sometimes if volumes don't appear in Startup Manager (what you get when you hold down the Option key at startup), you need to reset the Mac's PRAM, NVRAM, and Open Firmware. Shut down the Mac, then power it up, and before the screen lights up, quickly hold down the Command, Option, P, and R keys, until the Mac has chimed twice more after the powerup chime. Then, before the screen lights up, hold down Command-Option-O-F until the Open Firmware screen appears. Then enter these lines, pressing Return after each one:

     

    reset-nvram

    set-defaults

    reset-all

     

    "The reset-all command should restart your Mac. If so, you have successfully reset the Open Firmware settings."

    http://support.apple.com/kb/TS1812?viewlocale=en_US

     

    How to eject a cd from the internal cd drive:

    eject cd

     

    List of devices:

    devalias

     

    List of variables:

    printenv

     

     

    ( nvram is the equivalent Mac OS X terminal command. )

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    Resetting your Mac's PRAM and NVRAM

    http://support.apple.com/kb/HT1379

     

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    reset the PMU

    http://mrjcd.com/junk/PMU.jpg