Ghosting through images and video

[yelnoctrebor]

I have a 27" iMac from around 2012 that I've always been quite happy with. Over the last year or so I've noticed while watching videos in HD on YouTube that the resolution didn't seem quite right, like there was something I was seeing through the image. I finally realized that if I had a folder open under the browser I was viewing it in that it was the contents of the folder that were appearing like a ghost through the video.

Tonight was my kids' prom and I'm editing photos and have noticed that same thing happening to the images. I can see a ghost of other open windows through the images.

This isn't so bad its distracting, but I keep thinking its a problem that will be corrected during an update. Now that I've noticed it I can't seem to un-notice it. Well, it's been a long time and multiple updates and nothing has changed.

I was going to try to post a screenshot of the situation, but it is easiest to see when dragging the photo around. Easy to see during video because the image is always moving so you can see the stationary "ghost" behind it.

Has anyone else experienced this? Is there a solution?

[ferrarr]

I believe, Apple had a recall for that issue, but it ended a while ago? Are you in the U.S., or another country, which may have longer warranty/repair claims? Do a web search for 27 iMac video card recall.