Greyish Smudge marks behind the glass screen.

I have the same problem with my iMac 27" (mid 2011)... The smudges and marks started on the top left side of screen and now on the right side.. it feels like it’s getting worse and worse every week. So I took my iMac to Genius Bar today and I was hopping they can “magically somehow clean it up".. But unfortunately apple guy checked my iMac and told me there is no option for cleaning those marks.. and the LCD needs to be replaced. Now I’m just reading your comments and I must say: I’m very jealous of those who got lucky and got a replacement for free under quality program. I don’t have apple care so my replacement can cost me $540 (Los Angeles area, California)… so not gonna happen.. I’m just afraid that in few months my screen will look really bad. And now it’s tricky to work on retouching photos.. I'm really disappointed...

I seem to be having a similar issue, however mine doesn't look like it does in any of the pictures or videos I've seen on this. On my 2011 27" iMac there is an egg-shaped silver-coloured mark in the top right quarter. The mark is clearly visable when the machine is turned off, and when it is turn on becomes semi see-through.

To be honest it looks like condensation! But how could there possible be condensation on the inside of the screen? I've attached a picture here of how it looks with the iMac turned off: https://www.dropbox.com/s/au8tofr6e7g7l2y/screenshadow.JPG

It's worth noting that a couple of months ago I had the iMac repaired at an Apple Store due to a graphics card failure. Could this be covered under the warrenty of that work? (the iMac itself is now out of warrenty)

Update: It seems that it is indeed condensation. After about an hour of the iMac being turned on and the screen now warming up, the mark has halved in size. I'll leave it running all day and see if it disappears entirely.

So my question then is how on earth has condensation gotten inside the screen? The only thing that has changed in this room recently is I have moved it from one side to the other (now further away from the window than it previously was)

Have you looked at the environment where your iMac is being used to see if it is contributing to this issue? Are you using the computer in a basement or other area where the relative humidity is high, giving the opportunity for the moisture to condense out when it hits a cooler surface such as the glass on the iMac before the iMac has warmed up? If there are windows in the room where the iMac is being used, do you notice condensation forming anywhere on the windows during certain times of the day?

http://en.wikipedia.org/wiki/Condensation

Running the system for an extended period of time will help drive out any moisture, however the iMac is not a completely sealed system, so if the conditions are right in your environment the issue could return depending on the seasons and relative humidity. In areas where condensation is an issue it is common to install de-humidifiers.

My iMac has been in two different cities and developed the same screen issue. Plus my screen just stayed discolored or smudged or whatever it is but it was always there once it appeared and progressively got worse. It would not matter if it had been on for a long time or off for a long time it was always the same, just growing over time.

I'm speaking in the past tense because I finally bit the bullet and lugged it into my closest Apple store and just as the first time the service I got was fantastic. They put in a new screen for no charge with my AppleCare no questions asked. Plus they actually had the screen in stock so it was finished in just 4 days. They were even able to get me checked out while they were having issues with their system today.

Overall happy with everything but if it shows up again I'm not going to wait a year to take it in again. Hope I don't have to and can hand this computer down to my son when I upgrade.

I'm just throwing my hat in to this. I've had to have the screen replaced 3 times now I think. I've kind of forgoten because there have been multiple trips to the Apple Store for this issue. It's getting really old.

No smoking. No crazy humidity levels. Nothing even remotely abnormal. So another trip on Monday to the store. There needs to be another solution.

A 75 page thread about this issue is no small feat. 😐

kmfurdm -

This thread would be closer to 150 pages if Apple didn't redact it so often. Most of my comments have been removed. I've had to replace my screen three times.

Same thing as you; we're a non-smoking household in Wisconsin. We originally had this problem when we lived in Albuquerque; one of the most arid parts of America. And yet Apple takes no responsibility. I have to beg/scream/cajole them into honoring Apple Care's explicit statement that they'll do in house repairs for free.

They have replaced my iMac once. I have been told if the problem occurs again they will replace my iMac again. However, when I called in September to schedule a replacement/repair Apple has mysteriously lost my repair requests. Now, I can't get anyone on the phone...or on the website...or via email...how convenient for Apple.

I'm done buying Apple products. I might stick with the phone but the desktops are a waste of money.

When I took my iMac in to have the hard drive replaced due to a recall they fixed this problem too without me asking, now if they could also fix the optical drive problem I would be happy. It appears that Apple will not admit to a fault such as this and you are on your own when looking for a fix.

Hi guys,

I am considering buying a new iMac, models recently announced after October 2013. But after reading this post, I am really getting worried.

Does this problem persist on the new models, or is it just for the old models? Thanks a lot.

So my mid-2011 27" iMac with AppleCare just started showing signs of this problem. After reading about it and speaking to an online rep, they insisted I had to take the computer to an Apple store for service (saying an in-home service was not an option).

I live in the city of Pittsburgh -- so a major metro area -- and as I started packing up my computer and realizing that I wasn't keen on lugging around this massive compouter for fear of damaging it, I decided to take a look at the AppleCare Protection Plan booklet to read the fine print.

If you flip to page 20 in the AppleCare Protection Plan booklet, it reads:

"Onsite service is available for many desktop computers if the location of the Covered Equipment is within 50 miles (80 kilometers) radius of an Apple Authorized Onsite Service Provider."

So I just now called Apple support, read this sentence word for word to the rep on the phone, and he acknowledged that I am indeed eligible for this service. Naturally, there aren't any AASPs in Pittsburgh, so I have to take it into the Apple Store. I'm frustrated by this, but I wanted to share this fine print with others on here -- hopefully you can use it if Apple resists your request to have an in-home service and there is a nearby AASP.

I've been trying to tell people this very thing. So many people lug their iMac to the store when they don't need to. And I've experienced the same where they tell me I have to bring it in and I tell them I don't have to and then they back off.

I too had this problem on my 2009 27" iMac.

Apple replaced the LCD shortly before my Applecare ran out. The problem has recurred and once again I have the dark smudges on the right side of my screen.

The problem has been identified as dust collecting between the lcd and the backlight diffuser. Several videos on Youtube show how this can be fixed by the owner, although it is not for the feint of heart.

If one doesn't mind taking apart their iMac, it is a DIY project. I will do mine in the next few days

Shame on Apple for a poor design.

Aloha,

I just read through several of these posts. I have had my 27" iMac since October 2010 without a hint of any problems. I don't use it every day since I have an iPad, so it is in sleep mode most of the time. Today I had several tasks to do that required a "real computer". After it was on for about 30 minutes I noticed a huge grey/fuzzy smudge over about 30% of the screen. My extended warranty expired 26 October 2013......so I thought "just my luck"! My husband is a retired IT specialist, so of course I expected him to miraculously 'fit it'. He did some trouble shooting and called Apple Support. The lady was very nice but not very helpful. However, as time went by with the computer on (not in sleep mode) the grey fuzzy smudge started getting smaller.

In one of the posts I noticed that a person from the Phillipines had the same problem and was told it was an environmental issue (humidity). Well, I have to totally agree. We live on the southeast area of the Big Island of Hawaii and have been getting a lot of rain the past week. My year old stainless steel LG refrigerator is also covered in haze due to the humidity.

So, I have to agree that it is environmental factors (humidity) and I'm very thankful the smudge is totally gone.

I had this issue on my previous iMac (2009) twice and this one as well (2011) once, so did my Father in-law and also a couple at work. All different locations and all based in the UK which, to be honest, is not known for its humid climate.

Since Apple swapped out the screen un-questioning (didn't even power it on at the Apple store, just accepted my word and booked in a replacement screen) I haven't suffered the issue in 14 months of use.

I can be added to the list of late 2012 iMac (bought it in June) owners with grey smudges. Bottom left and right corners behind the glass; the left side is a dark grey smudge resembling a large thumbprint, the right side is a collection of small oblongs. It appears to be gradually getting worse.

To be honest, I'm done with Apple. I love Mac OS and could never use Windows , but their hardware is overpriced, bearing in mind the components they use aren't special and are just as likely to go tits up. After years of defending Apple I fel like I've paid an absolute fortune for a pretty, slim box, and I feel like I should go back on everything I've said in their defence and admit that, yes, they're taking the **** with these machines.. I'm not sure what I'll do in the near-future (if it gets much worse I'll just buy another monitor to use with it) but this computer was a bloody s***load of saving so I'll make it last as long as possible.

I was terrified before buying this iMac as I had read a lot about the possibility of image retention, I have none of that (touch wood) but now this has appeared. For a 2000+ Euro machine this is not on. This is a proper moany post I know but on my income I had to plan saving for this about two and a half years in advance, so I think I'm entitled to have a bug up my arse about it.

I'm also in the Czech Republic. There are no real Apple stores here (only the online store) and they don't sell Apple Care because of pretty decent consumer rights. Really can't be bothered having someone fluff up replacing the screen (I took my Macbook Pro into the most reputable of the Apple resellers/repairers here to replace the logic board, they scratched the s**t out of the case somehow), only to have this problem resurface again, which according to many others, it will.

TL;DR Sadface.