Pink square dots on Display (mid 2010 27" iMac)

Discussion in 'iMac' started by jstockamp, Aug 23, 2013.

  1. jstockamp macrumors newbie

    Joined:
    Apr 28, 2005
    #1
    Has anyone seen this before?

    [​IMG]

    Pink square dots randomly start appearing and flashing on the screen. Have restarted and reset the PRAM.

    Any ideas?
     
  2. Mr Rabbit macrumors 6502a

    Mr Rabbit

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    'merica
    #2
    Do they always occur in the menubar or do they appear elsewhere as well?

    Depending on this it could be anything from software corruption, video card fault, RAM fault, etc.

    With them appearing in your screenshot though you can at least rule out the LCD panel or video cables.
     
  3. Maxx Power macrumors 6502a

    Maxx Power

    Joined:
    Apr 29, 2003
    #3
    That is most definitely related to GPU failure (eventual). Is your iMac one of the GPU failure-prone models ? Some of the newer models are under "recall" for service on the GPU.

    See this page for a few examples of video card issues seen as artifacts (games or not):

    http://www.playtool.com/pages/artifacts/artifacts.html
     
  4. Mr Rabbit, Aug 23, 2013
    Last edited: Aug 23, 2013

    Mr Rabbit macrumors 6502a

    Mr Rabbit

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    #4
    The "recall" is a repair extension program (REP), not a recall. There is a difference. A recall implies that the component is definitely faulty and will be replaced regardless of symptoms. The extension program acknowledges that there may be faulty components in the computer and that based on this those components will be replaced regardless of warranty status for a set period of time if they end up showing a specific set of symptoms. i.e. If you failed to purchase AppleCare the video card may still be covered two years later if this specific failure occurs.

    If the iMac in question really is a mid-2010 27" then it doesn't fit the criteria for the recently announced REP, as it's specifically for a range of serial numbers for the "Mid 2011" 27 inch generation. You can see more info at iMac (27-inch): AMD Radeon 6970M Video Card Replacement Program
     
  5. Maxx Power, Aug 23, 2013
    Last edited: Aug 23, 2013

    Maxx Power macrumors 6502a

    Maxx Power

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    Apr 29, 2003
    #5
    No one is going into a great deal of technicality on the nomenclature. I did use quotation marks around the "recall", so it is not literal.

    There is no reason why a mid-2010 27" iMac can not have GPU failures when they also run fairly hot, in fact, I do think this has been raised a few times in the threads (here or elsewhere).

    FYI, the pattern looks a LOT like VRAM issues.
     
  6. Mr Rabbit macrumors 6502a

    Mr Rabbit

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    #6
    I understand but from my point of view, as an ex-Genius and ex-service technician for an AASP, misrepresenting such things only leads to spreading false information. People are accustomed to recalls meaning "something is wrong even if I don't see the problem and the company wants me to bring it in to fix it", which typically is the case for actual recalls. When REPs get mislabeled as recalls that mentality kicks in, resulting in lots of frustrated people getting turned away from Apple stores and AASPs, returning home and (as I see time & time again on here) complaining about how Apple refused to fix their computer even though theres a "recall". It makes it a bad experience for both the Genius/technician/Apple and the end user. This was VERY prevalent back in the MacBook Pro Nvidia REP days. That's the only reason I'm a bit pedantic with these issues, because I've had to handle those fires many times when misinformation was spread.

    I concur on all of this but A) the REP doesn't apply to mid-2010 iMacs, so even if the video card is the culprit it may not be covered if it's out of warranty, and B) there can be multiple "very likely" causes for this type of video distortion. The aluminum enclosure iMacs do run hot (though typically managed) and I've replaced more than a few video cards in them over the past few years, no argument there.

    Without knowing the specific build of the Mac OS and the status of the different components in the iMac I would refrain from jumping to conclusions. I agree that it's likely a video card but I've seen far too many technicians jump to that same conclusion only to later trace it back to RAM, software or even the logic board.

    I forgot to mention in my original post... You might try running Apple Hardware Test (AHT), it's a built in diagnostic that is actually pretty decent in uncovering hardware faults. If you've reinstalled the OS then it may not be built in but should still be on your gray system restore discs. This KB article explains the process - Using Apple Hardware Test - HT1509
     
  7. kenetic macrumors regular

    Joined:
    Dec 29, 2006
    #7
    Lug that big sucker to Apple store and have them test it out. I had mine test it out and it's a hardware issue. GPU needs to be replace. Since mine was out of warranty, they ask for $400 to replace the part.

    I said "thanks" and took my machine home. Didn't pay a dime for the troubleshooting.

    Good service, but lousy hardware.
     
  8. Maxx Power macrumors 6502a

    Maxx Power

    Joined:
    Apr 29, 2003
    #8
    Fair enough, for what it is worth.


    There could definitely be other causes. I suggested, based on experience, the most probable and common one. I suppose if the OP's computer is using an integrated GPU with shared main memory, I would have said the RAM might be an issue as well.

    Your other suggestion to do the AHT is a good idea. Just as well, if the OP has Bootcamp/Alternative OS installed, it would be a good idea to check if the problem manifests itself (usually as other forms of artifacts, since differing OSs' use the GPU-acceleration differently). Then it would be more conclusive along with the AHT.
     
  9. richol macrumors newbie

    Joined:
    May 20, 2014
    #9
    Pink squares

    Did you get this problem fixed yet...I answered this last night but apparently it didn't go through...mine has recently been fixed and running for over a week now with no problems
     
  10. ScottBedford macrumors newbie

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    Jul 3, 2014
    #10
    How did you fix yours?
     
  11. scaredpoet macrumors 604

    scaredpoet

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    Apr 6, 2007
    #11
    Fair enough... but in the interest of fairness, I should also be a tad pedantic and point out that in many of these cases with bad GPUs, PARTICULARLY the Nvidia 8600 series GPUs in those MacBook Pros that you mention, it's acknowledged and proven that not a few, nor a batch, nor a certain selection of the line are fauly, but rather, each and every GPU in the series has the same design flaw and has the propensity to fail. It's not a matter of if, but when, and the "when" depended greatly on individual usage profiles, and what people did with their laptops.

    Further, the standard resolution to such REPs was to simply replace the logic board with the failed GPU with another logic board bearing the exact same, flawed model of GPU, which only meant that eventually the same failure mode will present itself, in time.

    So, you're right, they aren't recalls. Even though by rights a PROPER recall *should* have been performed, and those individuals huffing that Apple wouldn't take in their not-yet-failed-but-still-flawed GPUs most certainly had a valid reason for their furstration.
     
  12. richol macrumors newbie

    Joined:
    May 20, 2014
    #12
    To make a long story short...I had a tech at Staples look into it after exhausting all other suggestions... he did a number of things to the IMac but what really did the trick was as follows. He found out that these computers have a problem when going to sleep and then waking up again...I am not sure how he did it but he somehow made a change which doesn't allow the computer to go to sleep...it just goes to screen saver and that protects the screen....I never shut this computer off! Since he made that change ... back in May2014 ... I have not had the problem again with the random square dots flashing on the screen...it has been over 2 months now and still no problem! Do you know any techs that would be able to disable your sleep mode? He said it wouldn't hurt the computer to be running all the time as long as you had a screen saver set up...it also would not hurt to shut it off at night if that is your preference....it is just the sleep mode on this model of the 27" IMac that gives you the problems. Hope this helps !
     
  13. ScottBedford macrumors newbie

    Joined:
    Jul 3, 2014
    #13
    Ah I see. I'll try that, however sometimes mine does it immediately after booting without having gone to sleep. But anything is worth a try. Thanks mate!
     
  14. richol macrumors newbie

    Joined:
    May 20, 2014
    #14
    I was quite surprised that this cured my problem...originally I thought it was a Mavericks problem as it started happening shortly after I installed the new software...prior to this fix I fully intended to back off and re-install Mountain Lion but now I am running fine. To be fair he did try wiping out and re-installing my hard drive from my time machine backup and then he re-installed Mavericks...I took the computer home and it seemed OK for about a week...then back came the squares...thats when he corrected the sleep problem. As you were saying...previously my computer would also act up even after a re-boot...now it is OK no matter what I do to it.
    Now I have a strange situation with Safari...whenever I try to enter it directly from an email...it just sits....even if I try to click on history and re-enter there...seems the only way to get it to open up is to go to file and open a new window...then the Home screen will come up...still trying to figure that one out!
     
  15. Mr Rabbit macrumors 6502a

    Mr Rabbit

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    #15
    I get what you're saying. FWIW, the design flaw you point out was exacerbated by typical usage behavior that Apple doesn't approve of. The whole "it's an Apple portable not an Apple laptop" thing because Apple insists that users use their portables on tables (hard flat surfaces) rather than laps, couches, etc. The aluminum housings were basically used as heat sinks, dissipating heat throughout the underbody of the Mac, which when used on a lap/soft surface loses a lot of it's efficiency.

    Hence why my mother's 17" 2.4Ghz MacBook Pro has yet, from purchase in late 2007 to this day, to display any of the REP symptoms. Outside of traveling once or twice a year it never moves from her desk. Same reason none of the six 15" 2.4/2.2 MacBook Pros used behind the Genius Bar at my old store ever showed the REP symptoms, they were never moved from their flat little platforms.

    They have the same flawed design, sure, but under Apple recommended operating scenarios (use it on a flat hard surface) failure wasn't nearly as prevalent.

    Oh, and they went through either two or three revisions of logic boards during the REP time frame. If you were one of the early failures then you likely got a rev 1 board. A year or two later though and you'd either have a rev 2 or rev 3 board. This, as far as I can recall, is similar to all of their (and most manufacturers) REPs.
     
  16. ScottBedford macrumors newbie

    Joined:
    Jul 3, 2014
    #16
    So I tried that suggestion but it didn't work.

    I have however since fixed the problem. For those interested, it's a bit involved. It's about 'reflowing' the gpu which literally involves baking it in an oven to melt all the solder bits inside of it and let them re-harden with no physical defects such as cracks or any separations.

    You need to pull your screen out of your iMac, take the graphics card out and remove the heat sink and thermal paste, then place the graphics card in the oven for 10mins at 200 degrees Celsius. Let it cool for 30 mins then reattach the heat sink with new thermal paste, and reassemble the iMac.

    My iMac was unusable before with constant lock ups. I was hard resetting several times daily after waking it from sleep.

    It's now working flawlessly and has been for about 4 days. No lock ups. No artifacting. And the repair only cost $2 for thermal paste, about 1hr 30mins of my time.... And some balls to pull your expensive iMac apart!
     
  17. mrg1 macrumors newbie

    Joined:
    Jan 5, 2013
    #17
    Cold

    Just started seeing the same thing on my mid-2010 iMac 2.93GHz i7, ATI Radeon HD 5750 graphics card. For me it starts in the morning when I wake it from sleep, so it seems to me its a problem when cold, not hot. Usually it goes away in a few minutes after warming up, but occasionally I see it during the day, so it seems like failure is coming.

    As an electrical engineer who has done mini-reflows like discussed above, I am impressed that anyone would try that. I have taken this beast apart twice to put in an SSD and replace it after it went bad, so I know how delicate that procedure is. Not sure I want to risk the reflow option, might just take it in to get it fixed if it won't take too long. I also found a place online that will do it for $288, but you have to ship it to them :

    http://www.galaxyhp.com/27-inch-iMac--ALL-ModelsbrbVideo-Card-REPAIRb_p_510.html

    Seems like with shipping it might be cheaper ( and less worry ) to take it to my local Apple store in PDX.
     

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