Greyish Smudge marks behind the glass screen.

I suggest you try it yourself and see. I have encountered those spots before two separate times. Both times the problem was solved with suction cups, and a quick cleaning. Sometimes the easiest answer is the right answer. I don't believe that Apple has an official sheet on this yet - which is why they may be replacing the whole screen prematurely.

Take a grey spotted iMac into the Genius bar to get any sort of service that requires they remove the screen, such as a HD replacement. When you get your computer back, your grey spots will be gone. I'm sure they clean the glass too.

🙂

I removed my screen,after my HD crashed.I didnt have apple care,so they want to charge me $350,but you buy HD for 150,and you can do it in 30min.But after everything,my screen has still marks.In apple store they told me its from cigarete smoke.So iMac is for non smokers.

Welcome Nikola. Impressed that you replaced your HD on your own. That's very cool.

When you removed the glass did you clean it? Also, you have to be very careful when you are putting it back not to create pressure points.

Yes, smoke from candles and cigarettes apparently can cause these marks. I would think in those cases that the marks could be cleaned off. They might be very difficult to clean off. It's not just the smoke but the airborne nicotine that can be pesky.

I probably mispoke by saying this issue is "typically" pressure related. I don't have enough information to make that assumption. What I should have said was that in my experience, those spots have always been pressure marks. And it would be foolish to replace the entire LCD without first taking the glass off, and cleaning it. 🙂

Holy heck!!! There is NO way I am going to take apart my iMac! I can just see it now, I'm so nervous when I am applying a screen protector to my iPod Touch or my iPhone, I can't imagine removing my SCREEN from my computer!!! I feel faint just thinking about it. I don't have a Genius Bar near me, just our local 'Mac Store' that I am assuming is affiliated with Apple. They aren't very reliable and usually pretty surly when I go in to ask them questions.

And if Apple is ignoring the problem that seems to go back a few years (according to all the threads I have read, which are MANY), what is a person to do?

Oh my.

its very easy to remove a screen.First protection on screen doesn't have nothing to do with a screen,its just Plexiglas protection,that you can remove with out any suction cup,just slide your nail in space between plexi and aluminum frame,and you can easy pull it out.There are just a magnets to hold it together.Stain is under the glass from screen,which is not easy to be removed.And to remove whole screen,you have to remove 8 screws,and HD is under the screen.So there is no way that you can wipe off those stains.

I want someone to tell me what we can do it,I thik that is a shame for company like this,to have such a big problem with their "most expensive product"

BTW after almost 2 yesrs my HD crashed.

Hi it's Judith ..I posted wayy back about the same issue in India...tried to get it fixed when I had a service...they say they cleaned the inside screen but told me I need a new LCD(?) for 25,000 rupees..about $600...surely if it was just a matter of pressure spots the problem would have disappeared when they did the clean???

it's really clear there is no unified approach by Apple service centres globally to this issue and that those centres are not being informed of the issue by Apple customer service central...certainly my centre tried the "environment" problem but I told them that wasn't true given the hundreds of people on this thread...all over the world too

I couldn't get a replacement ..my repair shop wouldn't come at it..out of warranty for 6 months...

won't EVER be buying NOR recommending the imac..though I love all else with it...

lol, yeah it's not for everyone. If you have AppleCare, then you absolutely should not do this. If you are still eligible to buy AppleCare, then I highly advise getting it. However, if you don't have AppleCare and can't get it - then you either need to recruit a tech savvy person to help you with the screen removal or pay Apple or another authorized Apple repair place (avoid Geek Squad) to help you with it.

It's actually relatively easy to do. Here's a video:

http://www.youtube.com/watch?v=9cHMHzq5E5I&feature=related

You don't need the exact same suction cup device that the guy uses in this video. You can buy suction cups at Bed Bath & Beyond or Home Depot or Lowe's.

I'd still like to know if it's only a 'cosmetic' issue or could the computer get damaged over time?

As much as I would love to sift through the 32 pages of this thread, can anyone clarify if this is an issue where there is some sort of condensation on the inside of the glass?

iMacs ventilation pulls air from down near the speakers to be ejected at the top of the machine. So in a humid environment, the iMac screen may become cloudy of smudgy on the inside.

To work around something like this I have found that leaving the computer on at full brightness for several hours in a low humidity environment gets rid of this issue and hasn't returned in the cases that I have looked at.

Hope I am on the right track 😝

Happy to welcome all the newcomers to this thread!

So far I've found these links to best describe what I believe most of us here are experiencing:

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

(great disassembly images half-way down page)

http://www.hardmac.com/news/2011/04/05/investigation-of-the-marks-on-the-imac-sc reen

Bottom line is that, for me at least, this is something (dust/particles/whatever) that appears to be between the LCD and backlight. Those two links describe exactly what I'm experiencing. For me it's definitely not as simple as leaving it on / drying it out / removing pressure points. Thanks for the suggestions anyway though!

I agree with your assesment, and add that the flow of air deposits material on both the inside of the glass and on the LCD surfaces. The amount of air and deposits are very slow to build up. Every six months I remove the glass and clean both the glass and the LCD.

Please check out the links in my post above yours, if you haven't already. The kind of issue that I am describing/experiencing cannot be cleaned by simply removing the glass. It requires complete disassembly of the LCD screen to get to the particles that have built-up against the backlight.

Sorry , I missed your details. Thanks for the links.

I'm starting to think the only way Apple will recall these iMacs is if they start bursting into flames.