Edsam

Q: how can i jump start my G5 mac ro tower?

When i push the power button to start my mac pro is whirls for a second and stops. I think i was once told that is i hold down a cowple of keys and then push the power button it would start. Will this work? If l yes then what are the keys i need to hold down. Thanks in advance. Ed

iMac, iOS 5.1.1

Posted on Jan 13, 2015 12:08 PM

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Q: how can i jump start my G5 mac ro tower?

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  • by rccharles,

    rccharles rccharles Jan 13, 2015 1:46 PM in response to Edsam
    Level 6 (8,486 points)
    Classic Mac OS
    Jan 13, 2015 1:46 PM in response to Edsam

    You may be thinking of the PMU reset button.  See last article on first page here:

    Power Mac G5 Blank screen and no chime on start up

     

    also...

    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

     

    Should the fail...

    Try taking the battery out for 10 minutes.  Put battery back in.  Cross fingers. Power the machine back on.