Sweet98 Hero

Q: iMac G5 Boot Up Problem

I have an iMac G5 running OS X Lepoard. When I boot up the computer it has lines going accross the screen ( my youtube video of it happening http://youtu.be/Hb-BiNcN7kA) and It will not boot up all the way but I can get it in safe mode. I tride reseting the PRAM and I did a HDD check in single user mode and still it won't work.

iMac, Mac OS X (10.5.8), G5

Posted on Jul 5, 2012 5:59 PM

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Q: iMac G5 Boot Up Problem

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  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Jul 5, 2012 10:22 PM in response to Sweet98 Hero
    Level 8 (39,326 points)
    Mac OS X
    Jul 5, 2012 10:22 PM in response to Sweet98 Hero

    Unfortunately, it might be a hardware problem, such as graphics hardware, power supply, logic board...

     

    Here are some things you can try, in case the cause is less serious.

     

    Reset PRAM, if you have not already

     

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

     

    Also reset SMU (power management).  This is the procedure for iMac G5.

     

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

     

    When you connect it back to power, I saw in the video that you were using a direct connection to a wall outlet, by itself.  That's good, to rule out a faulty (or over-crowded) power strip.  Be sure to disconnect ALL peripheral devices; start it up with only the power cord connected, then add just a standard keyboard and mouse.  If that makes a difference (and it starts up properly), run it that way for a while to see if it continues.

     

    Check the vents along the bottom (and elsewhere) for accumulation of dust, blocking airflow.  That could cause overheating, which may result in video issues.  If this is the older type of iMac G5 that is easy to open up, you can also check it internally for dust.

     

    If the PRAM battery has never been changed, it could be weak or dead.  That can cause odd startup issues, but usually not like the issues you have.  The PRAM battery for an iMac G5 looks like this.

     

    http://eshop.macsales.com/item/NewerTech/CR2032/

     

    The fact that it works better in Safe Mode makes me think it is related to the graphics hardware.  In Safe Mode, the graphics hardware is not being used to full capacity, so it might work more reliably (if it's becoming faulty).  For similar reasons, it could be the power supply, which may be less "stressed" in Safe Mode

  • by rccharles,

    rccharles rccharles Jul 7, 2012 8:56 AM in response to Sweet98 Hero
    Level 6 (8,506 points)
    Classic Mac OS
    Jul 7, 2012 8:56 AM in response to Sweet98 Hero

    You have a problem with the video chip.

     

    Here is how to tell...

      Shutdown your machine.  Hold down the shift key.  Poweron.  Bootup will be longer.

        Wait awhile while you harddrive is being checked.

      An article on how to boot into safe mode.

        http://support.apple.com/kb/ht1455

     

    Runs OK in safe mode...

    Running in Safe mode leaves out some video drivers.  Which results in your machine not using advanced video hardware. As luck would have it, you can run the safe mode video drivers in normal mode.

     

    Here is how:

    https://discussions.apple.com/message/16057567#16057567

     

    Look through the above thread.  See the second page.  You don't have to read through the first page.  Just go to the part where I try a solution that works.

     

    Summary of G5 problems. Includes instructions on a hardware fix for the brave at heart:

    See -Rotten Apple- articles in both of these threads.

    https://discussions.apple.com/thread/4023152?tstart=0

    https://discussions.apple.com/message/18700825#18700825

     

    Robert