Dirt-like screen issue O_O

I have the same problem. I finally took in in to the Apple Store, they are going to replace the glass and screen.

I'll be keeping my fingers crossed that it will not re-occur.

Believe me, your not alone. I had the same condensation like problem starting in the right hand corner of my screen and it would slowly get bigger towards the middle. Some days worse than others. I had the apple store replace the whole screen and glass and check for a good seal. They also ran a system diag. test and everything passed with flying colors. So I thought my problems were solved,,,,WRONG!! Its happening all over again,not as bad as before yet, but enough is enough. As far as temperature is concerned, like the person who mentioned their iMac was by their window, that would make sense if it is a real cold window by a warm screen but, I'm in a closet size sound room that gets hot quick and if it is going to condensate it should do it in the first 5 to 15 minutes not 2 hours later like it does. It is like the hotter it gets the worse the condensation gets. There should be no cold air left by that time to make it condensate other than the wimpy cooling fans. I just want to let everyone out there know that if you get your iMac serviced for this issue it might not be fixed. Sorry for the bad news, good luck friends.

I purchased my 24" Aluminum 2.8Ghz iMac in October of 2007. I have this very same screen burn in issue, and have had it fixed 4 times now.

Just today, the issue started up again. I am officially fed up with making trips to the Apple Store to fix this same issue over and over again. At this point I have no confidence that the issue will ever be fixed, and as soon as my AppleCare expires, I'll be stuck with a lousy product.

I will never purchase another iMac, nor will I allow any of my family to purchase one, and I will do my level best to strongly urge anyone else that I come across not to purchase one.

I traded down to this iMac from my Power Mac G5. That was the best computer I have ever owned, and I sorely regret selling it to get this iMac.

This started happening on my Alum iMac 24" bought July of 2008. I took it in about a week and a half ago. The first store I brought it to, the "Genius" immediately ruled it as burn-in and indicated it was my fault. Even though I tried to reason with him that burn-in looks more like images or text left on the screen, he wouldn't budge. I then took it to another store where the "Lead Genius" took one look and immediately authorized a LCD change. A few days after I got my iMac back with the new LCD, it started happening again. The first time it happened, I would see the "dirt" towards the top of the screen, now it's occuring on the left-hand side. I turned it off for a few minutes and turned it back and and noticed it did clear up a bit, but after a few more minutes of it being on, it got worse. I brought it back to the store and and authorized another LCD replacement for it. I told them I have a feeling it might be heat related, that iStat Pro showed temps inside the iMac at 120-130 degrees but it seems that it went one ear and out the other. We'll see how this new LCD works when I get my iMac back..