Q: Greyish Smudge marks behind the glass screen.

My G5 iMac developed screen discoloaration when it was 3 years old:

http://tech.kateva.org/2008/02/my-imac-screen-dark-band-at-top-of.html

My 2009 iMac 27" developed screen discoloration when it was about 3-4 years old. It's a bit different though, the blotchy dark area is most obvious when it's first powered up after being cool. It fades as the machine warms up and is usually imperceptible a few hours later.

In my case the machine was serviced last year by an authorized Apple repair shop. I don't know if the discoloration is related to the service, as we all know the iMacs are hard to repair.

I don't expect Apple to do anything (though a recall would be nice). I won't buy another iMac though. I'd like to see an SSD Mini with iMac specs and an external monitor or three. The iMac is just too problematic and too hard to fix.

An update after a conversation with the manager at the Apple store.

As the bulk of my complaint was about the attitude of their staff he has dealt with that.

In terms of the the actual issue with the screen he siad he was not qualfied to deal with it as the Apple Genius' know more than him .

He asked me email feedback@apple.com which I have done , I know this will make no difference but I will play along with them for now. I think there is a need gather some real figures of how many people have been affected by this issue. it is a matter of principle now the stores are unable to do anything as their advice from the top is to ignore these issues .

Will keep you updated if i progress anywhere

I have the same problem - just noticed it within the last two weeks when looking at a white background document. In January 2013 I purchased the late-2012 imac 27" which came with a bad pixel (stuck in green) in the middle of the screen, which I accepted. Now I am starting to see grey smudges appear at the bottom right hand corner of the screen. I thought it was dust on the outside, but no, it is inside the screen. In my case, this computer has not moved from my glass desk since I purchased it. I live in Madrid Spain, a dry climate  with low humidity, and I have a cleaning lady who comes every two weeks to dust, vaccum, and wash floors. There is never visible dust on this desk, so I am not sure how or what happened to create this distortion on my imac's screen.

@twernsing, I think it's just an issue inherent in the design unfortunately. My situation is remarkably close to yours, even down to the glass table and the cleaning lady visiting every two weeks. Is it just bottom right corner for you, I have little mark there and a larger one at the bottom left.

Will you be contacting Apple about it?  Do you have AppleCare?  I'm not sure if Spain has the same law as the Czech Republic where the initial warranty must be two years overriding the standard manufacturer one year warranty.

So this is almosy exactly like my experience. Fixed less than 12 months ago and once more a darkened left-hand to the screen.

My son was using a mid 2007 imac (24"). He got a new iMac because the 4 GB limitation.  So I've been using this mac, and I noticed that there are these grey smudge marks on the monitor. Sort of like they run in a semi spiral...  At first I thought it might be some kind of burn in, but then I couldn't imagine what image could have made these marks. Come to find out it's rather common from threads here and on google.

It doesn't seem too notible when there is a background of colors, but I'm just wondering does it just worse?  I can see it when the computer is off, and on a white background.  There are also some yellowish broken lines (only really noticable on a total white background) going verticle about six inches from each side of the screen.

Other than that, the computer works fine. 

So, since we've had it since 2008, is it too old for any warranty coverage. Is it worth dragging down to the Apple store to see if they'll fix it for free?  I've had other problems that they did fix out of warranty... but they were written up offenses.

It's totally usable now, but for how long?

Just noticed grayish smudges near the bottom right of my 21.5 inch iMac that I ordered back in Feb of 2013 (currently out of one year warranty period).  I was cleaning my screen and noticed that some "dust" wouldn't come off and after further examination, noticed that the problem seemed to be under the screen.  I've read thru a few posts, but haven't had time to check all 84 pages!  Can someone summarize if the effected owners have any recourse if the system is out of warranty?  Very annoying that such an expensive piece of hardware would be susceptible to such a problem.

I have a 27 iMac, and 2 of the smaller one (forgot which size) that have had the LCD replaced 2 twice each.  Though, Apple has replaced them they said they will not do it again.  The LCD's all have the greyish smudge on them on the top corners again. 

I work in a very clean office and can not understand why this wasn't a RECALL instead?  This is so annoying?  I'd love to hear others with solutions to their LCDs.

I have a 27" iMac, i bought it 2007 directly from apple maxed out, I have replaced the display twice already, the first time apple covered it, the second time I had to pay for it $700 in long island NY, each time the display starts building smudges which start getting stronger over time, then after 2 or 3 months the display starts to turn off by itself which lasts for about 2 months then it's done it will tunr on for a few seconds but it won't go further.

This is the third time this happens, i had this done at around christmas 2013 so it's been 6 months since it last happen (note that it was the same time frame the first time it happened)

Now the smudges are coming back to this new display and I know i have about 6 months before it becomes useless.

I've been an apple user for a while and this is my third mac, the first one i've had such issues with. I was stupid and didn't get apple care because i never used it and with this one i keep doing it. Even if i had gotten it by now it would be expired (i bought this one june 2011) and it would have been the third display to go bad. Also note nobody smokes in my house.

I am extremely disapointed with Apple and the quality of a $3,000+ computer, the display went bad just after a year and it keeps happening.

This is a manufacturing issue, the part is obviously defective and they ignored it becuase not enough people had issues.

Also for the record i use this mac from 9 to 5 and then after hours also as needed.

27" iMacs were introduced in 2009 so I assume that 2007 is a typo. Did you get AppleCare with it? Regardless of whether you had it or not, if it was still under 1yr warranty Apple should have replaced the display as many times as necessary without saying a word. If not, there's BBB, FTC and small claims court.

I had 2009 27" with AppleCare, screen was replaced 3 times. There was no 4th screen replacement, I got late 2012 brand new machine instead for free. That one also got display issue, guess what, they replaced it, no questions asked.

I have the greyish smudge too on the iMac I bought in 2011.  Found this problem this year, but I cannot tell when it appeared.  Of course my Apple Care was out of date.  Just went to the Apple store for a frustrating experience.  They "Apparently" do not know about this problem... even never heard of it... well I found that page... well those 84 pages today!  That's a lot of people that share the same problem! They wanted me to pay 500$ for a new scren.

Well.  I do think that... 

-This problem is caused by a manufacturing problem.  (it's not grease under the window.)

-I am not the person who is manufacturing these computers.

-A screen that last for only 3 year is not a good screen in my own opinion. 

"Now Mr Jobs on your cloud in the sky... I have a question for you: "Would you be a happy customer if you had bought a computer that cost more than usual computers, because you beleived in the product and after 3 years the screen is broken?  Would you reconsider what you think of the company who sold you this computer?" 

-I think I have paid enough when I bought the computer.

-This is not what I was thinking about the sturdyness of Apple computers.  I had an excllent experience with a previous iMac that was no longer supported.

-This is not the experience Apple sold me, in their advertisements... and it's not the HD that they've promised me.

-The guy at the Apple Store told me: "You know, it's electronic... it breaks!"  Ok, so why is there other machines same as mine that don't have this screen problem?  And by saying this I can now ask myself if Apple is applying some planned obsolesence to its products... just asking. 

-Apple care... ok Apple care.  A beautiful name for a prolongated insurance... when I go to Apple, I do not want to have the same buying experience as if I go to Future Shop.  And if the screen is doomed, i'm not the entity who built it defective.

-As a customer, I do feel I'm being let down by the company who made these computers. 

-After my visit to the Apple Store... No one could even tell me what happened to my screen... however, there was one thing sure... I had to replace it for 500$. 

-Yes, I do think I've bought a lemon. 

-Yes, I will telle this story to my friends and relations... they will surely be more comrenhensive.

Me too on late 2012 iMac 21.5". Very small above recycle bin and finder icons so fortunately not really affecting the bigger picture. Been on the phone to applecare and awaiting their call-back regarding onsite fix!

Hello everybody.

...same ugly problem.

iMac 27, late 2012 model. Grey spots on bottom left corner (huge ones) and minor issue but clearly visible on bottom right.

Bought it online on janauary 2013 and received 2 february 2013, in Milan, Italy.

I'm very disappointed with this, such a price for such a screen.

No smokers apartment, no direct sunlight, air climatization and after less than two years the screen become like this.

This is my first iMac, the overall quality is great but come on...cannot believe such a problem with an apple product.

By the way, called support, I'm still on standard warranty (thank god in Italy we got two years standard warranty), and on telephone support I found a very kind person that helped me.

I took my iMac to official Apple Store in Milano and they changed the lcd screen, they were very fast as the same day (yesterday) they called me to say is ready to be picked up. Great ! I just hope this does not happen again. I think this is related with heat dissipation, not 100% sure obviously but some engineer in Apple must know.... I got to pick it up today, gonna update screen status and quality soon.

100% agree. The weird thing is that as I went to apple store yesterday (defective screen "grey spots" late 2012 iMac 27), they also told me that "never heard before". How is it possible ? I went there with a bunch of printed pages from this thread.

I'm waiting until closer to the end of my two year warranty (standard also in Czech Republic) before contacting Apple about the small blotches on my screen. It's not a big issue for me, but if I can get it replaced then of course I will.  Reading through all these comments, a common response from Apple is that they are seemingly unaware of the issue.  I wonder if a lot of people are just putting up with it, or are only seeing the problem occur once the standard one year warranty is up and therefore are wary about any costs involved. Could the majority of screens actually not have this issue?