Greyish Smudge marks behind the glass screen.

The iMac has a few layers that you can see... I would suggest taking it into an Apple store so they can remove the glass layer (suction to the glass and pull back... the glass is held on by magnets) and they can then clean the screen for you.

If an Apple Retail store is not close or an Apple Authorized Service Provider is also not an option. I would look at doing the work your self.

The glass level can be removed and clean both sides.

BE VERY CAREFUL cleaning the layer under the glass as you can leave marks. DO NOT spray anything on the machine only onto your cleaning cloth.

iKlear is a product sold on the web and is what they use in stores. Keep in mind it may not be on the bottom layer but on the opposite side of the glass.

Hope this helps!

GL!

Greetings everyone!

So I've just returned home from my very first technical support visit to the local Apple Store (or any Apple Store for that matter), and it turns out that the gray splotches are in fact dust, the cause of which was explained to me nearly word for word as: "... fans from the back and bottom of the case pull dust in along with air, and what you're seeing is residual dust trapped between the LCD and the light."

Whether or not that constitutes Apple's admitting a design flaw, who knows? But so far I've been set up for a free cleaning (replacement parts will be installed if necessary) all covered by AppleCare.

NOTE: They did mention, though very fleetingly, that environmental hazards such as indoor smoking can cause this and other display discolorations and distortions. I simply asked the Genius to smell my shirt in order to verify whether or not I was coming from a smoker's home.

All in all it's been a pretty painless experience thus far.

just what i thought, when you read my post one page back 😉

interestingly, apple states in the mid-2010 imac's manual:

"Do not operate your iMac in areas with significant amounts of airborne dust, or smoke from cigarettes, cigars, ashtrays, stoves, or fireplaces, or near an ultrasonic humidifier using unfiltered tap water. Tiny airborne particles produced by smoking, cooking, burning, or using an ultrasonic humidifier with unfiltered water may, in rare instances, enter the ventilation openings of your iMac and, under certain conditions, result in a slight haze on the inside surface of the glass panel that covers the iMac display."

so far, so good. this is something, that can be cleaned easily.

but: it clearly does not tell you, that there is danger, that the dust will also get between the LCD and the backlight. and trying then to blame that on the customer, seems a bit odd to me.

i can live with what's stated in the manual, cause it's a simple cleaning matter. but if i had known beforehand, that the stuff will find its way into the LCD itself, i wouldn't have bought my imac in the first place.

i would consider that to be a hidden flaw, as we call it here in germany, and it should therefore be coverd by warranty.

I have the same problem. I was given number for Apple repair centre here in Brno Czech Republic. They are not able to clean the LED for me and I was told there is nowhere else in Czech Republic that can. They will be happy to replace the LED for me at the cost of 11'000CZK ( 650 US). It's option I guess, however I am not so sure I could afford to pay out this kind of money every 12 months or so if the screen gathers dust etc... again.Unless it is replaced with an LED that is more sealed than the current one, butthen I guess I will only this in another 12 months or so.

One thought in my mind is that as an external display will cost me around 16'000 CZK I could always consider buying one although it does kind of defeat the object of buy a consolidated unit in iMac format in the first place. Also as I use my iMac to DJ and need to carry it around this is will be a challenge.

I do expect that the dust in my LED has been due to exsposure to elements fly around various clubs. I accept that as manual suggest that I would from time to time need to clean the screen from behind the glass panel but I really did not budget for the high cost of resolving dust inside the LED. Be helpful if the user manual covered this in the first place and those who sell them make customers aware of it when purchasing then I would have reconsidered buying it. But to be fair to those selling them they only act in good faith they are selling a perfect product, don't they ? :-) And it goes without saying that those customers investing in such a product really believe they are buying a perfect product given the price. Sorry for being a little bitter but I am clearly not a satisfied customer in case.

Other thought is to sell my iMac 27 and put money toward buying a laptop instead or perhaps a Mac Mini and 27in display. Only issue is that I will need to pay out11,000 CZK first to address the dust in the LED so far as I can not really sell it as it is. Also, to be honest it was the large display that was one of the main attractions behind my buying the iMac 27 in the first place, that and the consolidated unitconcept.

This is a real shame as I have loved and enjoyed using it and Apple products in general. I have to say also that many people have commented on how great my iMac is when I have performed and I have encouraged several people to buy one and they have. I only how their trust in me will not be in question if the same thing happens to them.

I still love Apple and it's products. I only hope this feedback will reach the right people. All feedback is good feedback after all :-)

Apple ! Please help !

After reading hundreds of these posts I'm fairly certain this is solid ground for a class action lawsuit. I'm only suggesting this given two facts. A) apple is trying to weasel out of there responsibility by blaming environmental factors, and B) it seems the issue has not been fixed.

This is an absolute design failure on apples part

I was thinking about this too. That's why the video dmidesign talked about doing would be good. There sure seems to be enough ammunition to proceed. My iMac 27" was fixed but we're only talking about after 1 year and it really needed to be done earlier. I expect to be holding onto this expensive iMac for at least 5 years. Am I going to be able to get my iMac fixed at least 5 more times without a hassle from Apple and why should I have to go through the aggravation anyway?

A reply to my original message. Under Applecare warranty, my 27" iMac was picked up by courier on Friday. This morning I received a call from the service folks saying that the smudges were due to a faulty LCD and that the replacement part would arrive in a day or two, and then I'd get the machine back. Hopefully, all will go well.

Interesting, so... Apple have said offically that this is a LCD fault?

Would you be able to provide a link to something in writting that confirms this?

Would you know if a repairing a faulty LCD is only covered by an Applecare warrenty only?

I have had my iMac 27 less than 2 years and was kind of hoping such a repair to a faulty LCD would covered within a 2 year warrenty.

Thank you in advance for any information you can provide.

Well, it's not Apple that is doing the work, but a company here in the UK they've obviously contracted to do repairs. That's who called me this morning. The person definitely said faulty LCD that was going to be replaced. That's all I can tell you.

Not sure if anyone else saw this post on the MacRumors forum, but a few weeks back forum member "Oggy" posted some photos of his iMac teardown to remove dust from between the backlight and LCD.

Post here:

http://forums.macrumors.com/showpost.php?p=12665931&postcount=38

Money shot of the dust particles here:

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

His complete set of instructions (viewable in the full thread, I just linked his post with the pics) describe a nicely detailed process for removing and separating the LCD.. but until my warranty is out and/or Apple pushes back hard on replacing my screen(s!), I'm going to hold off on this course of action.

Nevertheless, extremely helpful to be able to see that it is in fact dust between the backlight and LCD.. I wonder if someone brought in these photos to the Apple store (or an authorized technician), would they be receptive to "cleaning and (re)sealing" our screens instead of just replacing the whole screen and taking our chances on this happening yet again in the future? I'm wondering if there could be extra steps that technicians could take to ensure a tighter seal if we know for sure that dust is the culprit.

EDIT:

Sorry just realized dmidesign posted in that thread! Sorry if it's not news to anybody!

Message was edited by: BinaryMango

That won't help most of us in this thread. Or I should say, it will only get us part of the way. The dust is located behind the "second" LCD screen (which appears to be much more of a pain to disassemble), so just taking off the front glass panel won't do any good on its own.

Got a call back from the service centre and they have replaced the LCD. The mac is being returned tomorrow, they will provide a full rundown of the issue with my returned machine.

My sympathy to anyone who is being refused a repair on this, the service centre told me this was a common problem with the imac and that they had replaced many LCD's because of it.

To blame the user is very bad form on the part of apple when they appear to know that a design flaw has led to the problem.

Just to follow-up - got my mac back last night. Renewed my warranty with Best Buy. I am in the US and the "Geek" said they replaced the LCD screen AGAIN. I asked him do they know why and he said it didn't say. I said well this is the 3rd visit here with same problem since original purchase, so I will be seeing you again soon I am sure, and the next trip will be on you Best Buy bc under the warranty they will have to give me a new mac. The "Geek" just smiled. So sad to put so many people through this. You would think they would find a FIX, not a bandaid!!

Okay, so this is frustrating. My 27" iMac was returned today by the third-party service company doing the repair under Applecare. They replaced the LCD, so yes the smudging was gone, but there was a constant flicker and random pixels (hundreds of them) were flashing almost like stars twinkling. Every 30 secs or so the screen goes black, and then it all starts again. So now it has to go back to them again. Of course, they say it worked perfectly and passed all their tests before being sent back, but I've never seen anything like this... Weird.

Well what do you know, Another smudge person. 😠

All over the top of the 27" Imac screen, Seems my smoking has caused this and its all my fault!.

Its in for repair at the moment as Logic board / Graphics card also have been replaced!!!!!

So they want me to pay £500 for New LCD and Glass ( When this is clearly not the issue from what I have gleaned from this thread ).

Any ideas. Should I print every page of this thread off and compile a book, Print off the photos to add as well!

Stand my ground.

PS. This was a refurb machine is there anyway ( at the store ) that they would be able to check what the initial problem was with the Imac ( ie. bad display ).