Greyish Smudge marks behind the glass screen.

Hi everyone,

I also have this same problem. The marks are in the top left corner of the screen and appear to be 'growing'. I do live in a humid city, but I use air-conditioning and fans all the time.

Has anyone else in Australia had any success with replacement or fixing of their screen? Were there any costs involved?

Thanks everyone!

I'm having the same issues with my 27" refurbished iMac (late 2009). and after reading this thread, I'm not in a good mood. I just noticed the greyish spots a few weeks ago and it appears to be growing worse. As a freelance graphic designer, I'm stuck with two bad choices. 1) Put up with distracting grey 'smudges' or 2) Go without my iMac for a week while Apple fixes it (if they agree to do so at all)

Not happy...

I am expecting a call from Apple Support today to arrange collection and repair.
My concern is that this repair will not be a 'permanent' fix and that this will keep on recuring.
While the guy on the phone was very helpful, and did say that it would be fixed, he did not acnowledge the fact that it was a large problem for them when I mentioned the huge number of internet posts about the same problem.
I am not prepeared to accept that it is an environmental problem - are we all now supposed to work in a sterile 'clean room' - dont be daft!. These things, especially at this price level (if I amy use their own words) should 'JUST WORK'. I will update this when I have more news. So much for switching to Mac though - I did and now I cannot actually do what I wanted and get rid of this PC..

I find it hard to believe that this issue hasn't shown up on Apple's radar. Exchanging displays is costly and somebody at Apple must have noticed. Evidence suggests this problem has been affecting iMacs since at least 2006, yet there has never been an official statement by Apple (except for Apple China, which apparently ruled that whole country to dusty for iMacs). I suspect that it was decided that dealing with this on a case by case basis is cheaper than whatever it takes to permanently fix the issue.

It is hard to tell how many units are affected vs. the total number of units sold. But this thread keeps becoming more populated, and it is only one of many all over the web. I also suspect that a lot of people affected by this simply don't notice it due to their wallpaper.

Overall, this is a very frustrating experience. Even if you are "lucky" and Apple agrees to fix the issue on warranty, there is no telling what will happen when you show up a 2nd or 3rd time, not to mention the inconvenience of going through the whole procedure over and over again. On top of that, you may even end up with a refurbished display with some dead pixels, yellow tinge or both.

Affirmative, I have also noticed a few subtle grey smudges/strains in the top-right corner of my 27-inch iMac (i7 Mid-2010). They can only really be seen on a white or light-coloured background.

It was bought in and is based in Beijing which has notoriously dry winters so it does not seem humidity-related.

The darkened area is quite smooth (like a water stain) and does not really resemble dust (unless it is super-fine). On top of that, nobody smokes in the household and I keep my desk very tidy and vacuum regularly. It is also not near to any direct sunlight and has not really been used for many CPU/GPU intensive tasks.

I am in touch with Apple support in China to see what can be done, will try to give an update.

Apple does offer display replacement in waranty and apple care period, but this is not a solution, since i know few people that had few replacements within one year. It is a global and not enviroment caused problem and Apple should recognize it and work on final solution. Main problem is in vents which are pushing dust in layers of plastic diffusors since there is no good protection from dust, regular LCDs are protected since there is no vents. Solution is simple but demands construction change and separating LCD compartment from vents and better LCD isolation.

I bought my iMac 21.5" in Beijing in June 2010. Same smudge marks over upper left corner after 5 month of usage.

I think we have to attract public attention to this issue, write a collective letter or something. Is there any group on Facebook or elsewhere?

When I bought this iMac I was sure that Apple computers are almost flawless. Not so sure about it now after my 2 friends reported the same iMac screen problem and unwillingness of Apple to deal with it.

Mine is being collected between 11 am & 4pm today. Lets see what happens.
I agree that this is very obviously a design flaw or a manufacturing problem. I work in an office with no sunlight (all electric light), it is air conditioned and the air is filtered. Not exactly a sterile room, but it is a a very clean environment.To eliminate dust to the size level we are talking about here will be impossible in a working environment, let alone a home. To have a machine do this due to dust or water vapour in this day and age, that is such a high spec item is not correct in any way - and to use it as an excuse is truly stupid - and extremely worrying in a business sense.
As I said, I am now in no hurry to replace the other windows pc machines we use with a Mac.

Same problem here - Finnish bought iMac 27", manufactured 2010, three to five months into operation - developed grey dusty blotches on screen that are NOT either on the exterior protective glass, nor on the outside of the LCD panel, i.e. they are somewhere between the layers of the LCD assembly. Poor design, shame on Apple!

Another one here! 27 Inch 2009 iMac...

First time happened a few months after purchase and was replaced without question and now the second time they denied citing environmental damage. I appealed and Apple have agreed to replace the screen under apple care warranty.

If anyone has their claim rejected due to environmental damage just stand your ground and insist they fix the computer under warranty. Tell them its kept clean and dry, its not acceptable for an expensive machine to have this problem, countless similar cases reported on the internet etc. If they still aren't budging ask to speak to someone higher up.

Im guessing this will happen again, I wish there was something that could help prevent the problem. If it is dust, isn't there some kind of filter that could be placed over the vents. Heat?? I recommend installing SMC Fan Control - you can monitor the CPU temperature and also control the fan speed. Humidity?? Why doesn't this problem happen to other computer screens and TV's in my house?

With hundreds of cases each week worldwide the problem would be known to all senior Apple employees but I suspect they're trying to limit costs as a recall would cost them dearly.

Perhaps we should start a facebook group. With enough people and cases reported in one place, Apple may have to take notice. There are so many threads like this one on various internet forums, If they were all merged together it would carry greater weight!

Same here in L.A.

Bought thru amazon.com last July and noticed the marks about 2 weeks ago. I tried the white screen for a few hours & it didn't work. Then i stumbled upon this thread.

My phone tech support expired, but i'm still covered under the 1 year warranty. I am going to set up an appointment with my local Apple store and take it in for an eval. I hope they don't give me the "environmental" excuse. I will be prepared with info from this thread.

Thanks to everyone for sharing!

Me too. Got my iMac 27 inch Dec. 2009, started to see the gray marks last month. Called my Apple Care support line yesterday. No problem, he made an appointment for me to bring it in to my local Apple Store Just brought it to the Apple store today. No problem at all with them covering it under my Apple Care Plan. I did tell them about all of these discussions and that for some it happened again after the repair. My tech said he will make clear note of it and if it happens again after this repair it will be covered. New Screen will be over nighted sand installed tomorrow. No conversation of environmental issues came up at all. I'm in Colorado Springs (Manitou) and this is the first iMac they have seen come in for this issue. So for me I am satisfied with Apples response to this. I leave my Mac of 24/7 in a smoke free, very clean home office. I might start to shut it down when I'm not using it to see if this helps.

21.5" imac purchased uk April 2010.
Bought solely for photograph viewing and editing.
same problem
yellow rippled "watermarking" top left corner.
Replaced under warranty.
Apple said known problem, very quickly offered pick up and replacement.
Back with me after 5 days.
Good service, shame it happened in the first place.
Always kept in large ventilated darkened room.
I find it hard to believe it is environmental.

My concern is that it will happen again unless there is a design fix.
Has anyone with a replacement screen had a second failure?

I noticed "smudges" —almost looked like smoke— behind the glass of my 8 month old 27" iMac. Once I switched to a light background, it appeared all along the upper third of the display. I pulled the glass and found that the problem wasn't on the inside of the glass but behind the LCD. I took it to a nearby Apple store and they replaced the LCD. Took it in on Friday and had it back on Sunday. I'm definitely going to buy Apple Care for it before the warranty expires.

Two 24"er's here and on one they replaced the whole computer and 5 months later it came back. The other one started about 2 months ago after the applecare ran out. So this has been going on for 3 years. You would think they would figure it out by now.