Greyish Smudge marks behind the glass screen.

Same here. Two Months and big spots. iMac 27"

The problem? maybe airflow.

Edit: Use the warranty for this problem is really stpid...lost time...and then appear (think differently)

I've encountered the same problem. Greyish smudge appeared on the upper left corner of the screen a few days ago. I have a 21.5" iMac that I've bought 9 months ago. It took some time for me to understand that it was a screen problem, not "dirt", and I am now disappointed to see that it is not a rare problem throughout iMac users.

I've been using PCs for over a decade and decided to switch to a mac a year ago. I wanted to buy a high-quality, durable computer. Everything was perfect till yesterday, when I saw the smudges on my screen. Searched various forums for a possible (and permanent) solution but there's none. There are people who changed their screens several times but it seems that the problem re-appears within a period of time. So what should I have to do now? Should I change the screen too, and try to clean the screen if the problem persists, and never buy an Apple product again? Should I wait for the Apple to accept that this is actually a design problem and hope they'll call back my device? Or should I try to change my computer with another one? I love Macs, but not the ones with annoying smudged screens. Thought they were perfect. Now I'm feeling desperate not because of my wasted money, but because of the Apple's broken trust image.

Thought I would chime in as well and hope that Apple hears. I have also started to encounter this problem. Initially I thought it was just a dirty screen but I know see that it is behind the glass. Not sure if it is the inside glass thats dirty or the LCD. While looking at the screen, my smudges are on the top and bottom right hand side.

I have thge 27" iMac Model No. A1312 2.93QC/4x2GB/1TB/5750/SD

So far: Strange smudges on inner pane of iMac and broken Superdrive. Lovely!!!!

I phoned Apple up the other day. They said take it to the shop but it's not easy for me, so they said I could call them out but they would have to take it away and I need it at the moment. I have a year left on the warranty so I'm gonna see how it goes, it's only just noticeable on mine tbh, you can only see it on a white screen. I wanna see if it gets worse or not, then I will take it in or call them out.

I have noticed this recently on my 7 month old 2011 27" iMac. So am I guessing it's something to contact Apple about? Also does everyone lug their iMac into the local store, or get it picked up? Not sure I could manage to carry it into store as have a knackered shoulder at the mo.

If you're outside of 50 miles, I think, you can request they come to your home to do the fix. I have done it 3 times now. One time they insisted I bring it to an Apple authorized tech shop being they wanted it done in a "controlled environment". I agreed thinking that was a load of crap and when I lugged it into the shop they looked at me like I had two heads when I mentioned the "controlled environment".

Anyway after 3 new LCD screens, the last one wasn't done well with the glass having dust on the inside. I called to have someone come out once again. I mentioned that I was tired of this and how disappointed I was in the product and that soon enough I'd be calling on them again for yet another LCD and glass replacement. The next thing I know she mentioned something to the effect of maybe doing something about the situation. I was on the phone a long while and transferred and such but it was worth it because I now have a new 2011 iMac replacing the 2009 iMac. So far so good with the screen but I'm not counting on it. But here's the thing. My other iMac had the fans going more than this one. The new iMac is quieter except for one fan has a low sometimes irritating pitch. But I don't want the screen taken off to fix it. I think I can deal with it as long as the screen stays in good shape.

I have exactly the same problem on a top of the range iMac that is only three months old. Was in the apple store in hong kong today. And they said "we have never heard of this issue before" told me to wipe and restore the machine. I have used apple computers since 1996 for video editing and thought the iMac would be a good option for this, but now wishing I had gone with a tower as this must be down to heat issues as have only just started using it properly (long render times) and here we go heat marks inside the screen. Have no faith in apple computers any more as the build quality seems to get worse with every year. Maybe apple should stick to making phones and mp3 players.

Would like my money back but that won't happen, so thinking that this is going to be an issue with the machine for a long time. My 8100 from the 90s still runs, as do the laptops from 92. Like PCs I guess the iMac now has to be replaced every 18 months. Will be taking it in with postings from the forum to try and get this resolved. On the whole I have been very lucky, this is my first issue with an apple product, guessing it is now becoming the norm as the build quality gets worse.

Thanks for the advice.

hi all (again).

exactly after 1 further year i had to change the screen (27") for the second time

thanks I had the apple care plan, but at this rhytim next year I will change it for the 3rd, and last, time.

always same clouds, more diffused this time (I suspect last year they did not glued properly the new screen).

that's for apple quality..... at least at service they said nothing this time, just changed and go.

Fabio

Same issue, Late 2009 27" iMac with these smudges in the top left corner of my screen. Out of warranty and not sure what to do, clearly a design fault and hope Apple start a replacement program.

Add one more to the list: 27" iMac with the same gray artifcacts all over the screen. Some vertical, some weird and wavy. They began appearing shortly after the local Apple Store replaced a defective hard drive and have been getting worse ever since.

I've contacted them for advice and will follow up if there's a resolution.

Got an answer, but not a pleasant one.

Our business account rep recommended bringing it in. Their Genius said that it was obviously a defective display, but it was unrelated to the hard drive replacement they just did. And, since we didn't buy Apple Care, it would be $606 plus tax to replace the LCD. He also recommended just buying a second monitor and using that instead.

The message is clear: The iMac is not suitable for professional applications. It's a disposable, consumer-oriented machine that's going to fail in a couple years. We won't be buying any more for my department, and I'm going to recommend to the company at large and anyone who will listen to me: do not buy an iMac.

I agree with you pajama

I was planning on buying a load for post production but when I pushed the four month old one I had i.e. doing commercial work the screen started playing up, a yellow band at the bottom and grey smudge marks in the top left corner. They are just not up to pro work. And am going back to the old tower. Wish I had never bought it. I would be better off with a pc and adobe.

What a con... Steve jobbs the saint, no just a con man with a pretty face.

Add me to the list. This is my second screen. It only took a month or so for this smudges to come back after replacement. It is almost certainly heat related. I have been using SMC fan control to keep the temperatures down while gaming since the issue showed up a second time. For some reason, by default the iMac allows itself to hit close to maximum allowed thermals before cranking the fans up. It then only runs the fans just fast enough to maintain below 97C or so on the processor. When it is in this state, the back of the machine is almost too hot to touch. It is really disappointing this is happening. Since installing SMC fan control and running the fans around 50% of max, the back never gets above warm even while gaming.

I have finally decided to build a proper gaming PC, then get the screen replaced a second time and retire my late 2010 iMac to non-gaming duties only.

Apple really needs to take this into consideration especially since there are heavy rumors that the Pro line is going away. This will push power users and Mac gamers to the iMac platform exclusively where there is definately a thermal issue in regards to screen damage.

It seems the thermal dissapation capabilities are there, but the firmware is not taking advatage of them by allowing the machine to get so hot.

Yikes, thanks for the pic and fan advice.

Sorry if this has already been asked/addressed here, but has anyone been experiencing this screen smudge issue who does *not* use their iMac for CPU/GPU intensive tasks (like gaming, video editing, etc)?

I do, it takes longer (8-10 month), as I put a short timing for screeen saver.

but Still I changed twice in 2 years

😠

even in sleep (screen saver), it heat quite a lot....