My iMac 21.5" Mid-2011 (i5 2.7 GHz) has started exhibiting a strange behavior where small colored squares, about 1/8", appear all over the screen. They then proceed to dance around the screen as I continue to work on the computer. I've attached a screen shot. From searching the forums it appears others have this problem, but I am unable to find any threads that actually contain a fix. Any help would be very much appreciated!
iMac 21.5 Mid 20112.8GHz i7 with AMD Radeon HD 6770M 512MB
Same issue. It's becoming unusable.
Could this possibly be a much bigger issue with Mid-2011 iMacs and El Capitan?
Same Problem here with iMac Mid 2011 Core i7 and El Capitan. Any fix?
Nothing yet...
Just picked up my iMac after the repair. So far no signs of the little squares and no freezing. I'll report back in a week or so.
iMac is still running great over a week later. I'm calling this one solved!
Small squares all over screen
