Greyish Smudge marks behind the glass screen.

Interesting articles:

http://www.globaltimes.cn/www/english/sci-edu/china/2010-12/600774.html
http://www.derangedshaman.com/2010/12/11/imacs-suffer-from-irremovable-dirt-spot s-in-china-apple-says-country-is-to-dusty/

I brought this up a year ago and no one wanted to listen !!!

My mac went like this fater 3 months and Apple treated me like a piece of ****.

Fack them **** their products, I will never buy again from them.

I too have the same problem. Started manifesting itself a few months ago.
I use my iMac mainly for CAD work and play the odd game.
I do use Bootcamp some times but normally use Fusion to run the Windows apps that I need (Revit 2011, MS Office).
The smudge is located on the right hand side of the screen and extends from top to bottom,and it is only really apparent when the back ground is white. The mac gets warm but not too hot.
I have read quite a lot of discussions on the net re the smudges,so it isn't just a few isolated cases (It appears to be quite common).
I will be giving AppleCare a call in the morning. I will report back with their response.

I just found that my iMac has exactly the same problem (although not very serious). Sigh.....I have read many discussions including this one in the web. And start to question myself about the quality of Apple stuff (my iPod Touch 4G has experienced malfunction of peripheral buttons, which happened just around 1 month after purchased). Comparing to the past, Apple stuff is getting cheaper and more popular. We hope to see Apple is embracing the market more than before. However, the decrease in quality is in a way that consumers can't comprise with. I think Apple should take quality issues into serious account. iMac is not new product anymore, so there is no reason for it to be so immature!

I have called Apple for my case. And they just play me around with reseting PVRAM. Since the problem cannot be solved, they will send a technician to my home to follow the case. It is very likely to replace the LED panel, just don't want a refurbished panel with dead spots and more serious yellow tinge.

Should I go for Mac Pro when I decide to buy a new Mac? Or MacBook Pro? Until this moment, I still quite happy with Apples laptop.

I have to admit that I was rather hoping to never have to post in a Mac forum after so many problems with PC's..
I purchased an iMac (27" all the bells etc) in the hope of getting away from 'W' and had my fingers crossed that the yellow screen problem had been fixed.
Well I dont have the yellow screen, but these grey smuges / clouds have appeared over the last couple of months. Not there at first - then I thought they were on the photo of wallpaper. On loading a clean page (white) they are very obvious and annoying. This machine has seen zero use in 7 months as I was waiting for Office for Mac to appear before it becomes my main office computer. Now it has to go in for repair as soon as the program was loaded as writing docs with cluds over the page is simply not on.
Had to purchase Applecare to get it sorted as I did not fancy the hike to the nearest store (1.5 hours away and a pain to get the box to).
Not exactly happy about this I have to admit. They are not a cheap machine to buy new and I was hoping for a better experience. I wont be changing the other machines over in a hurry - tha'ts for certain.

Message was edited by: Steve2701

Message was edited by: Steve2701

I too have the same issues with a 27" iMac which is nearly a year old. I rang Apple as the machine is covered by Apple Care. The advisor was more than helpful, the machine is now booked in for repair at my nearest Apple Repair Centre. I did not get any hassle, no mention of enviromental issues etc. Whilst the issues around not having a machine whilst at repair etc are annoying, the machine (hopefully) will be repaired, presumably with a new display.
The display problems are much the same as those mentioned in this discussion, l do notice that when the machine is switched off, the display should be black, however, in the areas effected by the grey smudges (top left and right when turned on) - now show as a light grey (against the black) which vignettes at an angle down the screen.
I would also advise any user to switch the background to white to check, l always use a mid grey which is very similar in colour to the grey smudges - initially thought it was my eyesight!
Hope this helps.

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!