I am having issues where the mid-2011 iMac will crash when switching desktops, flash pixellated images at random locations on the screen, etc. I cannot do a screen capture on this since it will only capture what the screen should look like, and will not show the issue. I have uploaded two pictures of the display.
Any help appreciated.
iMac, macOS High Sierra (10.13.2), null
Is your graphic card a AMD Radeon HD 6970M? That year iMac had bad cards in some of them and had a recall on them instigated. The recall time frame has long lapsed but I'm guessing you have a bad card. You can verify that by taking your iMac to the nearest Genius bar and getting a free diagnostic.
My card went out a few years ago just within the time frame and I got it replaced free.
Is your graphic card a AMD Radeon HD 6970M? That year iMac had bad cards in some of them and had a recall on them instigated. The recall time frame has long lapsed but I'm guessing you have a bad card. You can verify that by taking your iMac to the nearest Genius bar and getting a free diagnostic.
My card went out a few years ago just within the time frame and I got it replaced free.
You're right abut the card no. Mine was a 2011 27" iMac. The screen looked quite similar to what you're experiencing.
You an try booting into Safe Mode, Mac OS X: Starting up in Safe Mode, and see if the problem persists. If it doesn't it could be caused by 3rd party software.
stmccann wrote:
Thanks for the info. I did try the Safe Mode a while back and it didn't appear to help the problem. I am now accessing different user accounts and am not having the same issues with those accounts. Any ideas?
Yup, the GPU has failed. So your choices are repair or replace.
Thanks for the info. I did try the Safe Mode a while back and it didn't appear to help the problem. I am now accessing different user accounts and am not having the same issues with those accounts. Any ideas?
Appreciate it. My card is a 6770M, I believe that was what was put in the 21 inch iMacs, and I'm pretty sure the 6970M is the one that was in the 27 inch iMacs.
What are the symptoms of a potential graphics card failure?
