3 Replies Latest reply: Feb 20, 2013 1:39 PM by DaveC
DaveC Level 1 (10 points)



2005 iMac (PPC) on 10.5.8. When viewing a picture in Preview or iPhoto get this strange column-like hatching effect on screen. Also, occasionally the whole display freaks out and looks like a dog's (cat's?) regurgitated breakfast, until a restart which seems to right things for a while. Afraid the graphics card is heading south, can anyone confirm please? Is it fixable or am I looking at a hole in my wallet? Many thanks for any any advice :-)




Picture 1.png

20" iMac G5 (PowerPC), Mac OS X (10.5.8), 2GB RAM
  • mende1 Level 10 (92,186 points)

    It looks like a graphic card problem.


    Old iMacs have got the graphic card soldered into the logic board so, if you are lucky and you find a place where you can get the logic board for your old iMac replaced (I doubt it, as it's a PowerPC-based Mac), it will be very expensive. If you don't mind, you should get a new PC or Mac instead of repairing this iMac

  • rccharles Level 5 (7,581 points)

    You may 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.



    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:



    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.





  • DaveC Level 1 (10 points)

    Thanks Robert, I'll give it a try although I'm now getting black-outs on the screen which require a hard restart to escape from.