Asking Advice on Possible Bad Graphics Card (GPU)

Discussion in 'iMac' started by dcayce, Jan 24, 2015.

  1. dcayce macrumors newbie

    Joined:
    May 9, 2009
    #1
    I've been dealing with some large scale issues on my 27" iMac and I'm looking for feedback on whether I'm on the right track for a solution. It began last year, and I had the problem resolved for a while after taking it to an Apple Store while it was still under the 3 year Apple Care coverage. That has since expired. The problems are now back, worse than before, to the point that I can barely keep the system going long enough to post this. The symptoms have been:
    • Thousands of small, multi-colored, pixellated squares scattered across my monitor, randomly appearing.
    • These squares are often blinking as large groups, while other areas of the squares will remain static.
    • Vertical and horizontal lines, sometimes broad, other times only a pixel or two in width.
    • Large irregular geometric shaped areas of solid black, white or color, sometimes static, other times blinking.
    • Occasionally on restart my desktop icons and icon bar will render as solid gray areas, forcing another restart.
    • Frequent screen lock-ups, especially when doing anything requiring the screen to redraw. This happens most in Logic, where the playhead is moving and the graphic of the sound wave is being rendered. Just a complete freeze, then either a blank white screen with an auto restart, or I have to do a forced shutdown, then restart.
    It's happening so much now, I can't do anything more resource intensive than type this in TextEdit, hoping I can launch my browser and post it on some forums.

    Mine is a 2011 series iMac, 27", and I know there was a problem with the GPUs during that time, where Apple did a recall and offered free GPU replacements. My serial number is outside the range for those qualifying for the replacement program, but I'm nearly 100% sure my GPU is the problem.

    What I'd like is a few opinions, based on the symptoms outlined here, on whether my diagnosis right, and what a good GPU replacement would be. I went into mine today, pulled the GPU and re-seated it, blew out a lot of dust accumulation, hoping these things would help, but they didn't. So I've been in there, and know the process. I just need advice on those two things.

    Thanks for any and all help.

    Cayce

    Processor 2.93 GHz Intel Core i7
    Memory 8 GB 1333 MHz DDR3
    Graphics ATI Radeon HD 5750 1024 MB
    Software OS X 10.8.5 (12F45)
     
  2. Dopeyman macrumors 6502a

    Joined:
    Sep 5, 2005
    Location:
    Los Angeles!
    #2
    I believe you have a 2010 iMac, not a 2011 iMac... Apple's program is only for 2011 iMacs...
     

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