beaulm
Level 1 (5 points)

Q: Can't start PowerMac G5

I realize that a PPC machine--however powerful--is probably not worth saving at this point, but I figured I'd give one last ditch effort by posting here.

 

When my computer starts up, the loading apple screen appears then it flickers blue for a second then goes completely black. This is the same for the OS X install disc as it is for my current installation.

 

When this behavior first started I could still get in using Safe Boot, where I tried a number of things to diagnose/fix the issue, but then when I tried disabling various kernel extensions I wrecked safe mode (now I get the prohibited sign of the circle with a line through it).

 

Some of the things I tried include:

  • Repairing the permissions from safe mode
  • Repairing the disk using target disk mode
  • Clearing caches, running maintenance scripts/cron jobs, rebuilding the LaunchServices db...
  • Running DiskWarrior from target disk mode
  • Running everything in Applejack
  • Zapping the PRAM and NVRAM
  • Resetting the SMU
  • Removing all non-essential hardware (disc drive, airport card, sound card, all-but-one set of RAM--of which I tried all sets independently)
  • Replacing the backup battery in the logicboard
  • Checking the hard drive for errors
  • Combing the log files
  • Googleing my problem

 

My first thought was that this was a hardware issue because it started with intermittent shutdowns, followed by me having the reset the SMU and/or the PRAM. The fact that I was at least able to get into the system using safe mode until I made software changes, leads me to believe that it could be a software issue. Perhaps it's a little of both. The only thing I can think of now is that the firmware got reset to its original (and unusable) factory settings, and that I need to re-update it somehow... but I'm not sure how to do that through Open Firmware or Target Disk mode.

 

I'm hoping an expert here will have a good idea or have experienced something like this before.

 

Finally, in case it helps, this is what it get in Verbose mode (right before "still waiting for root device"):

 

Extension "com.apple.driver.applepmu" has immediate dependencies on both com.apple.kernel

and com.apple.kpi components: use only one style.


Waiting on <dict ID="0"><key>IOProviderClass</key><string ID="1">IOResources</string><key>IOResourceMatch</key><string ID="2">boot-uuid-media</string></dict>

Powermac G5 PPC, Mac OS X (10.5)

Posted on Feb 24, 2015 10:28 AM

by BDAqua,Solvedanswer
BDAqua BDAqua
Level 10 (123,830 points)
A:

Does it boot into Open  Firmware with CMD+Option+o+f ?

 

http://docs.info.apple.com/article.html?artnum=42642

 

reset-nvram (press Enter)

set-defaults (press Enter)

reset-all (press Enter)

 

Have you done a PRAM reset, CMD+Option+p+r...

 

http://support.apple.com/kb/ht1379

 

In fact, do 3 in a row, takes a bit of time.

Posted on Feb 24, 2015 10:35 AM

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beaulm

Q: Can't start PowerMac G5

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  • by BDAqua,Solvedanswer

    BDAqua BDAqua Feb 24, 2015 10:35 AM in response to beaulm
    Level 10 (123,830 points)
    Feb 24, 2015 10:35 AM in response to beaulm

    Does it boot into Open  Firmware with CMD+Option+o+f ?

     

    http://docs.info.apple.com/article.html?artnum=42642

     

    reset-nvram (press Enter)

    set-defaults (press Enter)

    reset-all (press Enter)

     

    Have you done a PRAM reset, CMD+Option+p+r...

     

    http://support.apple.com/kb/ht1379

     

    In fact, do 3 in a row, takes a bit of time.

  • by beaulm,

    beaulm beaulm Feb 24, 2015 11:24 PM in response to BDAqua
    Level 1 (5 points)
    Feb 24, 2015 11:24 PM in response to BDAqua

    That totally worked--thank you so much! I'm super grateful for your quick and accurate help. For anyone else experiencing this problem, it was the Open Firmware step that did the trick.

     

    Any clue on what I might do to fix my install that I screwed up by temporarily booting with some of the (likely essential) kexts removed? I've put them all back now, but it still shows the prohibited sign when starting up. I successfully installed OS X on a different partition, so the machine is usable again, but without all my hardware drivers it's less useful and for such an old machine those drivers might be hard to find these days. Anyway, I'm much obliged and can't tell you how much I appreciate your assistance.

  • by beaulm,

    beaulm beaulm Feb 25, 2015 8:37 AM in response to beaulm
    Level 1 (5 points)
    Feb 25, 2015 8:37 AM in response to beaulm

    After installing OS X on another partition I was able to repair the permissions on my original install, remove the /System/Library/Extensions/BootCache.kext (per this guide), and restart into safe mode, then get things working from there. I'm not sure why I wasn't able to repair the permission from target disk mode.

  • by BDAqua,

    BDAqua BDAqua Feb 25, 2015 9:51 AM in response to beaulm
    Level 10 (123,830 points)
    Feb 25, 2015 9:51 AM in response to beaulm

    Great news, good work!

     

    On Permission fixes, one note, it'll use the parameters from the drive it's running from, which in this case was a different OSX version.