Q: Greyish Smudge marks behind the glass screen.

rockjano3,

Yes, I believe so. Dirt between glass and lcd maybe ?

I found same issues for late 2012 iMac models (MD096) include this one.

http://cafe.naver.com/inmacbook/978197

I've just reached out apple customer service.

An Engineer told me due to structure of late 2012 iMac, replacing screen would be only way to fix it.

I feel discouraged cuz they insist my warranty ends Feb 16 2014.

"Yes, I believe so. Dirt between glass and lcd maybe ?"

Well if you are lucky... but that is unprobable.

If it is only between the glass and the LCD that takes 5 minutes to clean up yourself (anyway computers should be cleaned in every half year iMac includid dust blowing up etc...).

It is more probable that the dirt is inside the LCD, that could also be cleaned but it is a LOT mor difficult (apple will NOT do it, they change the panel if they willing to do that)

Typical iMac problem... constructional problem...

rockjano

Same here, Late 2012 iMac 27. Bottom left and right corner.

I'm having this issue with my late-2011 27" iMac and it has gotten so bad that the smudge marks has now takes up nearly a quarter of the display. Since I've just started to have video card issues (as noted here: http://9to5mac.com/2013/08/16/apple-opens-graphics-card-replacement-program-for- some-mid-2011-imacs/), I dropped this off at an AASP on Monday morning as none of the Apple stores in my area had appointments until later this week.

I haven't heard anything yet, so I gave the AASP a call just now. They're still running additional diagnostics in regards to the graphics card, but they said the smudge marks are due to "smoke." They didn't elaboate, but they said they would be in touch with me tomorrow once the diagnostics are done.

I don't smoke. I don't live in a humid enviroment (I live in Vegas which is the exact opposite). I don't have any of the enviromental issues that Apple is claiming that causes this "defect" with the display.  I just want these issues fixed.

I have AppleCare on the machine for another year. If the AASP is to deny the repair or service, what are my next steps? Do I have to call AppleCare to enforce the in-warranty service?

cupboardoflove,

I believe smoke thing is common excuse of apple.

I think apple should fix it at no extra charge since you have Applecare on your iMac.

I assume it will invalidate the warranty, but the screen is held on by magnets, easily removed using suction cups and easily cleaned. I believe the smudges are due to humidity, dust, and a lack of a filter system.

Only if the dirt is inside the screen and the LCD but ususally it is INSIDE the LCD panel... that is the problem...

My 2009 imac just started getting these smudges. I'm going to try removing the screen and cleaning the back. I hope that works! Seems like a design flaw.

Hi Turtle,  I've got Late 2009 iMac Intel Core i5 2,66  with the same problem, for now more or less not so irritating. For 100% - design flaw, but what's the **** I still love it and with mixed emotion waiting (in vain) for Apple to wake up. Let us know if you fix the problem after all.

Try the executive level if tier 2 AASP deny. They will do it once and then their 'goodwill' which you paid for, expires instantly.

I just got a call back from the AASP last night and Apple has approved the LCD replacement. The AASP has only seen the issue once before, but knew it was a defect with the machine itself as already stated, the greyish smudge marks are inside the LCD and between the glass and the panel.

On the other side, they haven't found an issue with the video card despite that being the main reason I brought it in and the fact there's a replacement program at the moment (http://support.apple.com/kb/TS5167).

I have same problem with my Imac 21.5-inch, Mid 2010

Procesor  3,06 GHz Intel Core i3

Grafika  ATI Radeon HD 4670 256  MB

Memory

14 GB 1333 MHz DDR3

Any idea what i can do? This Imac was cost me a fortune 4 years ago, and im shure waranty it's gone. I read article about Apple that they spetially do things like this to force people buy new items, hope its a mit, i can't afford new iMac and i need him for my photography work. Can any one advice me what i can do? I am based in UK. Pleas help it is so anoing

It is over 3 years so Apple probably will not change the LCD. (you might try but it is not probable)

You should take a picture how the problem looks like and post it here. We can take a look.

1. You should remove the front panel with sucking glass-lifting tool. You can find video's on YT how to take out the LCD, you have to disconnect 4 kabels. You can clean the LCD unit and clean the whole machine inside (with some air can or compressor or just blowing it by yourself, compressor is the best).

After 4 years the mac surely very dusty inside it is anyway good to clean it.

2. If it does not help you can try to take apart the LCD unit and clean it inside it is a very delicate procedure but it can be done look video on YT also. I did it myself two times.

3. If it still no help that it might be that something is overheating inside the iMac, this was my case with my dying HD, I replaced it and whoala the marks I had disappeared. But your case might be different. I did not found too much dust inside my LCD others had more, dustier environnement or smoking whatever...

Just saw video and i am shure i will don't try do my self unles will find any vide show this clearly not in fas motion its don't look easly

Well..removing the front plastic and the LCD unit is quite easy. It must not be a problem... It might be just enough.

Taking apart the LCD unit is not easy, you are very afraid that you destroy the LCD (mine is 27") it took me 4 hors at the first time. it was a lot easier next time (of course)

You can also take it to an independent service station, that will cost some money (and most of them is not willing to take apart the LCD unit...)

Look for other YT video...

Hope I could help

rockjano