Greyish Smudge marks behind the glass screen.

Hi iSayuSay. Appreciate the thorough post, and I don't doubt that this problem has the potential to exist on all LCD's, but personally what I (and I think a lot of other folks on this thread) am experiencing with my iMac screen is not "clouding".

This has been my go-to link to best describe this problem (scroll half-way down for pics):

http://forums.macrumors.com/showthread.php?t=1101370&page=2

Or a close-up here of the real issue we are experiencing with our iMac's:

http://forums.macrumors.com/attachment.php?attachmentid=287668&d=1306956612

Whatever this fine material/dust is that accumulates between the LCD and backlight, that's what I believe is causing the smudges on my screen.

Again, not saying that clouding/mura doesn't exist; I've seen it myself on a friend's older LCD TV. But the fact that the person in the links above could take apart their machine, disassemble the display unit, and literally wipe away the "dust" (with some effort), leads me to believe this problem is not what you're describing in your post.

And, assuming that what I wrote above is true, then I think it is Apple's responsibility to address what I consider to be a material defect in at least some of their iMac's (ie, screens not properly/fully sealed, or whatever the culprit may be).

Hello BinaryMango. Thank you for your reply. Oh yes I'm aware of that thread you gave me. In fact I'm a member there with the very same nickname. I posted there too in the last page, I think 🙂

Some people eventually able to get rid of black spots by following Oggy's thorough guide, but a few people report otherwise too.

I think there are different types and causes which result the similar spotty/smudged/clouded LCD on iMac.

In my case I hardly believe it was a trapped dust. My iMac has this problem on upper right corner of the screen, and I game a lot on this computer for the first 3.5 months of posession (well it was new, you know how it is .. honeymoon! 😀 ) and then I had the display replaced once by Apple. It was clean and perfect again. Case closed! .. for a while

But I read it will come back again in many cases. So I arranged an experiment, this time I try to reduce the gaming time compared to before and ramp up the fan most of the time, within the same period (3 months or so) I can already see there are another smudges on almost exactly the same location as before, it's much less visible this time (now I conclude it because I dont heat the GPU as much as I used to).

That's why I thought .. the culprit is heat coming from behind. All kind of LCD will do the same when exposed to excessive heat. And because iMac design is to put computer machine behind the display, it happens in much accelerated pace compared to regular monitor, LCD TV etc.

I notice GPU heatsink can reach 80C when it's used for intensive gaming with the stock fans RPM, while CPU side relaxing at around 40C.

Ramping up the GPU fan to 3000rpm for gaming helps reduce the temp to 65-70C.

Well .. it's just my thought anyway. Thank you BinaryMango.

I suppose you have the same problem with iMac? How was that going? DId you follow the Oggy's guide or had Apple replace the LCD for you? And the most important question is ... does it come back in your case?

Same thing iun the Netherlands, there are a lot of folks here that have the "grey sport screen" issue.All of them seems to be iMac 27 inch. I have had 3 replacements in 2 years time. The last one was in septmeber. Last weel I called Apple Support 9I have Apple care) and expected the machnine now to be replaced. Eh, nog go. The lady from Apple told me that in fact I wasn't even eligible for a 4th replacement (but they were "willing" to make an exception for me....). They ivestigated the matter and she came up with the same ******** as pthers in this post decovered. It is a environmental problem..... Whena asking her to confirm this by mail she answered that this wasn't possible. I have no ideau yet how to address this issue properly.Perhaps some Twitter-noise will wake them up! Good luck everybody here.

When I got my first 27" iMac in mid/late 2010, I only got about 3 months use until the gray smudges appeared in the upper-right area of the screen. So I took it in to the Apple store near me and they replaced the screen no questions asked. (There's a much longer story here.. while replacing the screen they accidentally damaged my iMac's logic board and somehow screwed up the whole computer enough that they offered me a replacement, which I accepted. So instead of just getting the screen replaced, I have a whole new iMac and I'm a happy customer. Then, about 4-5 months later (this is now early/mid 2011) the gray smudges appear on my new screen as well. I also game on my iMac (Windows partition through Bootcamp) so I'm sure my temps are also getting fairly hot.

Maybe it is a matter of heat and not dust, or a combination of the two. I guess I'm just so blown away by Oggy's disassembly post and the literal "wiping away" of this.. stuff...

I am wondering why this hasn't gone to the media...anyone know an approximation of the numbers of people affected? I'm sure a story about apple ignoring their customers,the refusal to replace the machines of unwitting cutomers regardless of warranty and the whole issue with the design would make good headlines.....and corporations respond to such ...

i also played a lot of games when i first got my machine and the marks appeared within a few months, i note that my macair runs very hot when i game on it so i presume the imac does the same and the design makes it worse...

I suppose this thread is getting too long so people don't read it from the start anymore. But MOST(not all) of the smudge issues are actually the micro fine smoke/dust between the layers of diffusers between the backlight and the display. After having cleaned 4 of them I can testify of this that when you clean them well enough they are as good as new. It is true that they become hot but if you reasonably take care of your heat you will not burn the LCD. Use the fan control and pay attention to heat. I had a friend who put their iMac by a south facing window... between the sun and the games it burned it up badly. That being said. I think he was being pretty stupid. The more apple tries to "seal" the screens the worse the problem will become. When the screen becomes hot the air is forced out. As it cools the microfine dust and smoke is sucked into the screen. Since the screens CANNOT be completely sealed the more they try to tape the edges the more the dust will be focused in the small areas that are not sealed. If the screens are NOTSEALED AT ALL then it will suck the dust in more evenly and it will not be as noticable. I'm not sure why their design engineers have not figured this out yet. It's rather laughable actually. If you take apart other LCD's they are similar but are not nearly as tighly sealed. If the Design of the iMac was more segmented it would be better. For instance. Put the screen in it's own sealed area like piggy backing a laptop behind a normal display. Then you could seperate the air chambers and keep the video card from being mounted directly on the back of the LCD. (by way of example). And apple if you're reading this TAKE THE TAPE OFF THE EDGE OF YOUR DISPLAY it get's dusty a lot less and what dust there is is displaced more evenly. I have done this on the displays I have cleaned and they last a lot longer before becoming dirty again.

Well folks, I think it's safe to say that <REDACTED> won't <REDACTED> except for some <REDACTED> not complying with their <REDACTED> Apple <REDACTED> is a wonderful company.

Here's hoping that satire is not against this forum's Terms of Service.

But in all seriousness, we seem to be well on the radar regardless of certain terms or links that are briefly posted here. So the best we can hope for is to remain the top viewed / top posted thread in the official iMac Support Community and let people know they're not alone in their suffering. Of course, to do that we need to make sure that our posts qualify / stay up!

Spoke today with Apple Support in the Netherlands. I will have my fourth (!!) screen replacement (i have Apple Care). The guy that helped was very understanding and recommended to follow the support site without making any promises, giving hints or whatever. He took the time to listen to me and gave the impression that at least he was aware of the many problems as listed here and on other places. I made my initial call last week. Than I was really ****** of by his female superior who gave me the enevironment crap. When asking for a written confirmation by mail of this "so called diagnose" she refused stating that this wasn't the responsibility of the call centre. Anyway, nex screen, but no real solution yet. I have the impression that we are generating more noise and I hope Apple will respond in a way that matches their customer satisfaction statistics. Other than this I still like all my Apple stuff :-)

Good luck to all!

How to STOP being notified by email when new posts are added to this thread? It's really annoying, all my notifications are turned off in my otptions, any help? Thx...

Edit: Nevermind, i never realized I was always browsing with logged on an account and had another one I never used with notifications allowed... :/

While I appreciate the concern of both Apple and its forum contributors, I have to say that this matter is rapidly getting out of control. So; at the risk of my time proving wasted were this post to be deleted, I really must say that Apple should consider the embarrassment it is exposing itself to.

I am an Apple supporter of the first order and will continue to be so but every post that is deleted adds to the suspicion that appears to be gaining momentum. Moreover, these problems will be compounded once the press take an interest, and they will.

I believe it's time for Apple AND its critics to call a halt to this thread; for Apple to make a holding statement and for its critics to be understanding and allow the company time to consider its position.

There is clearly something wrong and while I don't believe some of the posts are entirely genuine, it is not a matter that can be brushed under the carpet.

And if you delete this, Mr Moderator, do pass it on up the line; Maybe someone will think again.

This is my first MAC with the same screen issues as everyone else on this thread. Awsome computer, but I feel that this problem not being addressed by Apple is ********! This is clearly a design flaw. Apple, if you want to keep a satisified customer from going back to Windows, FIX THIS PROBLEM!

So, if this is taken down, they've clearly updated their policies and what they will allow in this forum. But wow, I've never seen them take down an entire conversation like that yet. I'm guessing this issue is intesifying.

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I'm also contacting the press through my contacts, I suggest everyone does. I'm also going to other contacts at trading standards.

In addition to the MAIN PROBLEM my 10amp fuse keeps blowing on my Mac plug. I've replaced 3 amps in 4 days, moved it to a different socket, same thing. anybody else have this problem?

Thank you all so very much for posting these issues. I had a refurb in my cart ready to buy when I decided to venture into the forums for any last minute opinions. This has prevented me from purchasing an Apple computer until this is addressed. If anyone from Apple is reading this, it is obviously not an isolated incident and NEEDS to be addressed! I want to own a Mac!!!!