9 Replies Latest reply: Dec 31, 2012 7:44 PM by japamac
Ken Gast Level 1 Level 1 (0 points)

I will follow up with the model as soon as possible.

I assume this is a video card problem, but if someone could verify, I would appreciate it.



  • Computer occaisionally boots up like normal, but upon going to sleep, the screen is a series of horizontal columns of green lines.  I can see a green block where the cursor should be, and can move it around the screen.
  • Other times, the computer turns on, but the screen remains black (white LED lights up on monitor)



I can remotely access it over the internet using a screen sharing service, and can operate the unit this way.


Going to hardware profiler shows nothing under graphics card.


I have zapped the PRAM and replaced the battery.  No avail.



Is this a logic board issue, or gfx card issue?


If this is a video card issue, can anyone suggest a replacement?  I know it needs to be Mac OEM, or Mac flashed(not an option for me to do myself, no more Winboxes).


It does not need any specific performance criteria, my parents use it for web browsing and email.

  • 1. Re: Video card or Logic board?
    BDAqua Level 10 Level 10 (116,475 points)

    Hi Ken, very likely he Video card, but need specific nfo on the Mac for video card recommendations.


    Foes it safe boot?


    One way to test is to Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, Test for problem in Safe Mode...


    PS. Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive


    Reboot, test again.


    If it only does it in Regular Boot, then it could be some hardware problem like Video card, (Quartz is turned off in Safe Mode), or Airport, or some USB or Firewire device, or 3rd party add-on, Check System Preferences>Accounts>Login Items window to see if it or something relevant is listed.


    Check the System Preferences>Other Row, for 3rd party Pref Panes.

  • 2. Re: Video card or Logic board?
    japamac Level 7 Level 7 (24,390 points)

    Sounds like a bad graphics card.


    G4 or G5, here are your choices for AGP graphics card replacements, OEM or flashed:



    Late 2005 G5 only PCIe choices:


  • 3. Re: Video card or Logic board?
    Jacumba Level 4 Level 4 (2,325 points)

    It could be the monitor itself and not the video card. Do you have another monitor you can try, or is this a iMac with the computer built right into the monitor?

  • 4. Re: Video card or Logic board?
    Ken Gast Level 1 Level 1 (0 points)

    It is a Power Mac, it has an Apple Cinema display connected with the Apple Display Connector.
    I know it is not the monitor, as when this occurs, I can remote into it with LogMeIn, and when going to System Profiler, there is no card listed under the Graphics item.

  • 5. Re: Video card or Logic board?
    Ken Gast Level 1 Level 1 (0 points)

    Finally was able to replicate the problem.

    Here's what I have found.

    • If the computer stays off for a week or so, it will not start up with video unless left running for several hours, then manually restarted.
    • If the computer starts up normally, putting it to sleep for about 45 min will cause the green blocks to appear.
    • When the computer is restarted right away after the green blocks, the video does not come up, but connecting with screen sharing shows this in system profiler:



    Picture 12.png


    Attempting to start into safe mode produces no different results, still no video.


    There are no 3rd party pref panes installed, and this occurs with no peripherals except keyboard and mouse connected.


    About this Mac:

      Model Name:          Power Mac G5

      Model Identifier:          PowerMac7,2

      Processor Name:          PowerPC 970  (2.2)

      Processor Speed:          1.6 GHz

      Number Of CPUs:          1

      L2 Cache (per CPU):          512 KB

      Memory:          2.25 GB

      Bus Speed:          800 MHz

      Boot ROM Version:          5.1.5f2

  • 6. Re: Video card or Logic board?
    Jacumba Level 4 Level 4 (2,325 points)

    Where your sure it's not the monitor. With the green screen is a indication of video card or driver. I'd first work with the driver, re-install or update the driver. Unless you have a video card to swap out. I've only seen a video card go bad once in 10 years but it could very well be the card, but nearly every time it's been the driver.

  • 7. Re: Video card or Logic board?
    Ken Gast Level 1 Level 1 (0 points)

    I am quite certain that the problem is not with the monitor, as when this occurs and I connect to it with screen sharing, no video card shows up as being detected. How would I go about reinstalling the driver?


    I will be resetting the PMU shortly to see if that does anything.

  • 8. Re: Video card or Logic board?
    Ken Gast Level 1 Level 1 (0 points)

    Reset the PMU, no dice.

  • 9. Re: Video card or Logic board?
    japamac Level 7 Level 7 (24,390 points)

    How would I go about reinstalling the driver?

    You can't. These aren't Windows boxes.


    Drivers are a part of OS X. Only an occasional retail Radeon card has stand alone drivers, but those are always included in later versions of an OS.


    If you need drivers, update OS X with a combo update; example 10.4.11 or 10.5.8.

    Mac OS X 10.4.11 Combo Update (PPC)

    Mac OS X 10.5.8 Combo Update


    However, drivers aren't your issue.

    Graphics card failures are not uncommon, Mac or PC, and present as you describe, among other ways.

    A card without a proper ROM or driver should still have a vendor ID report in Hardware/Graphics.

    This I have seen with all Mac or PC cards (prior to flashing) in OS X.