9 Replies Latest reply: May 13, 2008 2:43 PM by SteffenMoestrup
nixn Level 1 (15 points)
Hi I have an intel core duo 17" iMac. I had no problems with it for the year or so I've had it, but one day I came home and tried to wake it from sleep mode and it wouldn't respond so I manually powered it off. After rebooting up, Mac OS X just displays distortion lines and jumbled graphics - and eventually the whole screen just freezes. I've tried reinstalling OS X, which had no effect. This ALSO happens when I go into my bootcamp install of windows. So this can't be an OS software related thing I suppose.

HOWEVER, the screen is perfectly fine when I boot into the mac install cd or a livecd, which leads me to believe that this problem occurs when video acceleration is active.

I took a picture of what the screen looks like, sorry for the bad quality:


Message was edited by: nixn

iMac 17" Core Duo, Mac OS X (10.4.10)
  • nixn Level 1 (15 points)
    Okay. After playing around with it a little bit, and being confused on WHY it's perfectly fine in the Installer CD but is scrambled in Windows/OS X... I decided to try running OS X in safe mode. (holding shift at boot)

    This works FINE. Does this turn off acceleration for video? Would that lead this to be a hardware or software problem ?? Obviously I dont want to run in safe mode all the time.
  • den.thed Level 7 (25,992 points)
    Hi nixn

    While booted from the Install Disk, use the Disk Utility to repair your iMac's HD.

    Look at: [Using Disk Utility to Repair a Disk|http://kb.wisc.edu/helpdesk/page.php?id=3810]

  • nixn Level 1 (15 points)
    The hard drive checks out fine. I dont see this as a problem with the hard drive?
  • den.thed Level 7 (25,992 points)
    OK the OS X seems to be good!

    {quote} I had no problems with it for the year or so I've had it, but one day I came home and tried to wake it from sleep mode and it wouldn't respond so I manually powered it off.{quote}

    Now because of what you said about it not waking from sleep, next do an SMC reset!

    [How to reset the System Management Controller|http://docs.info.apple.com/article.html?artnum=303446]
  • nixn Level 1 (15 points)
    Okay, I reset the SMC and it didn't have any effect.
  • ezio.m@mac.com Level 1 (10 points)
    just to let you know I have the same problem in a Early 2006 iMac 20" Intel, but just after I installed Leopard.
    I didn't find any solution yet.. so I'm curious to know if/how you solved the issue.

    Best regards,
  • schmia Level 1 (0 points)

    I have very similar problems with my late 2006 iMac 20". It was running perfectly and I experienced only a single crash within its first 12 months of operation.
    First day I installed Leopard it started to crash randomly. Some graphical errors appear on the desktop or in a window (1 or 2 complete or incomplete rows of wrongly colored pixel) and a bit later (can be minutes or hours) it stops responding. SSH logins from another machine are still possible. Problems are bit more seldom when I disable Quartz Extreme in the Quartz Debug Utility from the development tools.

    Today I added an external disk and reinstalled Tiger on it. I experienced screen garbage like in Leopard and sudden GUI halts, too.

    My hardware says: iMac5,1, IM51.0090.B09, SMC Vers. 1.9f4, ATI Radeon X1600, 128 MB, ID 0x71c5, ROM 113-xxxxxx-139, EFI 01.00.139

    Did anybody else experienced this problems? What do you think should I do with this machine? As I already said, I was working perfectly before the Leopard update.

  • molmedo1 Level 1 (0 points)
    Hey Guys,

    This thread pretty much touched all the issues I'm having with my 1.83 iMac. Any ideas out there on a fix yet???

    Thanks in advance,

  • SteffenMoestrup Level 1 (0 points)
    did any of you ever find a solution to this problem??
    I have experienced the same on my iMac after installing Leopard. Now I have installed Tiger again and the problem is no longer there. I would prefer Leopaad though so would appreciate a solution...