I am getting random graphic glitches/artifacts/distortion horizontal lines around windows (see screenshot). The recent recall program sounds like the issue I'm getting but I don't have a RADEON graphics card.
iMac (27-inch, Late 2012)
3.4 GHz Intel Core i7
32 GB RAM
NVIDIA GeForce GTX 680MX 2048 MB graphics card
iMac, OS X Yosemite (10.10.4)
My guess is your GPU is failing, if the machine is still covered by AppleCare then call them immediately. If you did not purchase AppleCare then be prepared for an out of pocket expense.
Also, you are vague about a recall program, you need to be specific as there have been hundreds of iMacs models over the years. We have no idea what you are referring to unless you are specific.
I'm having the same problem, started 1-2 months ago.
I work on Photoshop a lot, when that happens Photoshop usually either has the error as you mentioned or is just showing a black screen. A restart of the app helps. I also got this glitch on other Apps such as Spotify (screenshot attached).
iMac Late 2012, GTX 675
iMac (Late 2012) Display Graphic Glitches/Distortion
