14 Replies Latest reply: Jan 15, 2013 10:01 AM by John Galt
adison132 Level 1 Level 1 (0 points)


My powerbook cant boot. It freezes on fizzy apple logo.

(safe mode isn't working too). It looks like this:


Also it wont boot from install cd or

hardware test cd:


I tryed everything to fix it.

-reseted pram/nvram

-removed airport

-reseted pmu

-used fsck in single user


I hope that is only a software problem.

PowerBook, Mac OS X (10.4.6), PowerBook G4 12"
  • BGreg Level 6 Level 6 (17,495 points)

    See his Apple note on solving problems with booting. Can you hook it up in target disk mode via Firewire to another mac to run a disk repair? 

  • adison132 Level 1 Level 1 (0 points)

    Unfortunately i don't have another mac to connect them via firewire. But i performed disk check

    from single user mode and it said that disk is ok.

  • Knucklesmac Level 4 Level 4 (2,225 points)


    Have you tried booting from the System Restore Disk supplied with the PowerBook? Or a Mac OS X disk?

  • adison132 Level 1 Level 1 (0 points)

    Like I said before I can't boot from any cd like Hardware test or Mac OS X disc, it just ends up with freeze.

  • BGreg Level 6 Level 6 (17,495 points)

    Do you have an external firewire CD reader you can hook up? I'd sure like to run the Apple Hardware Test.  How about a bootable backup? If you have one, can you boot holding the alt/option key down when the bootable backup is attached via firewire?

  • adison132 Level 1 Level 1 (0 points)

    Basically I just want to erase everything and install system again (I don't have any important data on my disk). But I can't even boot to the Mac OS X Install CD.

  • John Galt Level 8 Level 8 (43,105 points)

    I realize you cannot boot from any Mac OS X disc, but please try booting from your Apple Hardware Test CD / DVD, or whatever disc that shipped with your PowerBook that has the words "Apple Hardware Test" or "AHT version xxx" printed on it.


    To do this, start your PowerBook and insert the disc as soon as the drive's mechanism accepts it, then hold an Option key to invoke Startup Manager:




    Using the cursor (arrow) keys, select the optical disc and press Return to boot from it.


    Does this work at all?


    If not, the next suggestion is to boot in Verbose Mode: hold ⌘ v while starting your Mac. The point beyond which it cannot progress will be shown as text. Transcribe it or attach a readable photo in a reply.


    Try removing and replacing your RAM if that is an option for you.


    This looks like a hardware problem for which a repair may not be economically justifiable. The contents of your hard disk may be retrievable using FireWire Target Disk Mode or by its physical removal and installation in an external drive enclosure.


    To eject the optical disc restart your PowerBook while keeping the trackpad button depressed.

  • adison132 Level 1 Level 1 (0 points)

    I'm pretty sure that my CD drive is ok.Also I forgot to tell that when i'm trying to boot

    Hardware test i got an "invalid memory access". I'm starting to think that my powerbook

    has got broken bootloader or something.

  • adison132 Level 1 Level 1 (0 points)

    When i select hardware test in startup manager:

    (I'm also a bit concerned about these weird green dots)


    Screens from verbose mode:


    after this screen goes all fuzzy


  • Knucklesmac Level 4 Level 4 (2,225 points)

    That last image would indicate some fault with the monitor or the graphics controller.

    This could indicate a hardware failure very similar to that I've seen on G4 12" iBook models.

  • adison132 Level 1 Level 1 (0 points)

    So is there any possibility to repair it? Im still corious why i can't boot hardware test.

  • John Galt Level 8 Level 8 (43,105 points)

    Everything looks OK right up to the moment the GPU fails.




    AHT requires a minimum amount of operable hardware to run. You indicated earlier that AHT said "invalid memory access" or words to that effect. No further diagnosis will be possible.

  • adison132 Level 1 Level 1 (0 points)

    Is it possible to confirm that GPU fails? What should i do next to repair my powerbook?

  • John Galt Level 8 Level 8 (43,105 points)

    A corrupted display tells you everything you need to know. It only confirms what you already observed in your original post.


    If you are so inclined you could shop for a replacement logic board from a reputable parts dealer. PowerBook Medic and iFixit come to mind. The supply is limited but prices are quite reasonable, and it will be guranteed. Be sure to specify the exact model required. Disassembly, removal, and replacement are tedious chores for the technically adept only.


    You could try eBay, as long as the board is guaranteed.


    Buyers on eBay essentially have the last word on returns these days. Sellers have no choice but to accept returns, as long as it is within the allotted time.