iMac display pixilation

[ccrobin1]

Imac 27-inch Mid 2010
2.93Ghz Intel Core I7
16GB 1333Mhz DDR3
ATI Radon HD 5750 1024 MB
OSX 10.10.3

At radon times after waking from sleep the display will have a pink/magenta square pixillations randomly on the screen that move whe the cursor is moved. The only way to correct it is to restart the machine and it will be fine until it happens again. I cannot recreat the issue, it will just randomly occur.


See attached image..

thanks

 

[illusionx]

Looks like graphic card issue to me.

 

[ccrobin1]

Thanks,,, any ideas of replacing the graphics,, without breaking the bank?

 

[illusionx]

No idea.
Did it just start happening? If not, since when?

 

[ccrobin1]

Started randomly with Mavericks and continued in Yosemite. I do not know if it is OS upgrade related,, or just started happening. As I have said it is random and I cannot recreate it. I am still trying to find clues as to what causes it to happen. All I know is a reboot clears it until the next time.

thanks