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Severe Screen Artefacts post Mountain Lion Upgrade

838 Views 13 Replies Latest reply: Sep 28, 2013 2:47 AM by El Deanio RSS
El Deanio Calculating status...
Currently Being Moderated
Jan 8, 2013 4:36 PM

I recently upgraded to Mountain Lion direct from Snow Leopard.  Ever since I have been getting weird vertical lines drwn on my iMac screen.


They don't appear all the time.  They appear in windows when I move the window around the screen. They sometimes appear on the desktop behind the window - but not always.  They appear in in Safari windows too.  If I scroll up and down the line stay in the same releative position. That is, I can't lose them by scrolling them off screen.  They are still there in the same shape and position when I scroll back down again.


They don't seem to affect Google Chrome.  They plague Safari and Firefox.  I have a demo version of iDefrag.  The iDefrag data window has vertical lines at random where none should be present.


Here are some screen shots - tain%20Lion/Screen%20Shot%202012-12-11%20at%2010.39.54.png


Moving a window about - tain%20Lion/Screen%20Shot%202013-01-08%20at%2023.22.49.png


Sometimes the lines spill over onto the desktop behind - tain%20Lion/ScreenFault.pdf


About my iMac tain%20Lion/Screen%20Shot%202013-01-08%20at%2023.09.35.png


iStat Pro Report tain%20Lion/Screen%20Shot%202013-01-08%20at%2023.21.40.png


Safari tain%20Lion/Screen%20Shot%202013-01-07%20at%2017.24.31.png


Safari scrolled up a bit - no change if scrolled off screen then back again tain%20Lion/Screen%20Shot%202013-01-07%20at%2017.24.10.png


This happens irrespective of what User Account I am logged in to.

iMac, OS X Mountain Lion (10.8.2), iMac 24"
  • animist08 Calculating status...

    A similar thing happened to my old HP Notebook but not nearly as severe, it was only 1 pixel wide. It would also disappear only to come back. But I eventually found out that it was related to a problem with the cable connector that connects the motherboard to the screen. It's only a remote possibility this is your problem because your lines are more like 5 plus pixels or even greater for today's Hi-res screens. But if it is the connector; when the lines are present wiggle the screen back&forth a little and see if the lines flash in and out. Hope you can get it fixed.

  • Paul_31 Level 6 Level 6 (12,220 points)
    Currently Being Moderated
    Mar 18, 2013 5:52 AM (in response to El Deanio)

    Sounds like a re-install of Mountain Lion would be worth a shot (did you keep a copy of the installer?).

    Checking the hard disk over is worth doing as well using the Recovery HD. Restart holding down Command+r and at the screen with four choices select Disk Utility, select Macintosh HD and click on 'repair disk'. If any changes are made click repair disk again until you get a clear pass. Quit out of Disk Utility and it'll take you back to the screen where you can re-install MLion, which will mean another 4gb+ download unless you already have the installer.

    As always, make sure you have reliable backup of all your data before re-installing (Time Machine or a clone, ideally). Doubt you'll need it, but things do sometimes go awry.

  • Paul_31 Level 6 Level 6 (12,220 points)
    Currently Being Moderated
    Mar 18, 2013 7:17 AM (in response to El Deanio)

    Fingers crossed it sticks. Glad to help.

  • Paul_31 Level 6 Level 6 (12,220 points)
    Currently Being Moderated
    Mar 18, 2013 8:51 AM (in response to El Deanio)

    Rollox indeed . Good idea to repost, hopefully others will chime in.

    Starting to look like a hardware problem unfortunately - hope I'm wrong.


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