Greyish Smudge marks behind the glass screen.

Just wanted to add a 'me too' to this subject. 27" i7 1 year old. The guy at the Apple store claimed it was environmental even though no one smokes, there is no humidifier, ... He said they'd fix it under Apple care just this time, but it is really considered user caused problems. I'd noticed this for the last couple of months, but finally decided to do something about it. As for heat related, this computer doesn't get used for games and only processes photos. I sure wish I'd seen this thread before I bought the iMac. I would have gone for a Mac PRO and an external monitor.

Hi - what did you say to apple to get them to replace the screen for you outside of warranty? I would like to do the same. Any advice would be grateful.

I had my screen replaced too, after it developed grey smudging. This is a warranty case. No need to say anything. It is preposterous to bring some kind of environmental damage, when most of our iMacs are sitting at home, with regular household dust levels (more or less). My idea is that the stuff that produces smudging is already INSIDE the LCD, and it is just released by heat of computer operation. 100% factory fault.

I am taking my 7 month old 27" i3 in for the second time for this. And I would completely agree with shura.sena above. This looks like literally finger grease smudges that then get coated by the residue used in machine.

I took apart my cars headlights once. Baked them, took them apart, painted, put something on the inside with super glue, and then sealed them back up. After 3 weeks I started seeing my finger prints on the inside of the light. The vapor residue from the super glue was attaching to the slight grease my fingers left behind. Same thing here.

****, watch CSI, it's practically how they lift finger prints off objects. This appears to be the same exact thing. It's there from the factory.

Have you ever thought of just throwing the iMac away and buying a new one?

Apple must get really sick of folk moaning all the time!

The same for me,

Imac 27 late 2009, apple changed the screen 1 time during the warranty, and now that I've the same problem, they say that it's due to how I use it.

I don't undersatnd why they don't solve the problem.

Still waiting them to react and find an issue to this problem because paying 2000€ for a computer with that kind of problems, it's crazy!

My iMac 27"(2010 model) has also suffered from marks/smudges on the led panel which got progressively worse over time. It's about seven months old and has recently come back from the store after it's second replacement display under Applecare. To credit Applecare, my local store where I purchased the iMac have been brilliant so far. I did have some frank discussions with the genius bar about why this is occuring and asked some searching questions when they mentioned possible environmental issues that could cause 'contanimation' of the led panel( extremes of temperature/humidity/smokers/direct sources of heat or light/dust) My iMac has otherwise performed flawlessly and the screen issues have just been a bit of a dissapointment/inconvenience in an otherwise wonderfaul package. I also wish i'd found this thread earlier as I would have probably bought a Mac Book Pro and an external monitor just as a fellow photographer did after he had similar issues with a recent iMac 27 purchase. If you have apple care its probably best to let your Apple store look for themselves and see that its not an environmental issue that is affecting your iMac rather than voiding the warranty by trying to remove the glass. I think I may extend my Applecare as I'd probably skip the machine before paying for a third replacement led panel out of warranty. Fingers crossed my current replacement screen will hold up.

I too have had the same issues with my mac. My warranty is under Best Buy and they replaed the LCD screen panel twice. Still had smudges so they sent out and when I got back they said it was a cleaning issue and normally is not covered under warranty. Now I am sorry I ever paid so much money for a system that has to be cleaned. The smudges are back again and I am almost out of warranty and dont know if I should renew or not and now I am stuck with fighting to get the problem resolved again. I never had this problem with pcs!!! My home is smoke free, and the enviorment issue if bs!!! I will never buy another mac!!!! Apple should fix this or offer free cleaning of the panel bc this should not be!!!! I purchased my mac in 12/09 as well. I am so upset about this issue and feel very taken advantage of by Apple!!! They should stand behind their product!!!

Guys. New to forums. Just to add my weight to this.

I bought my 21.5" Intel iMac in November 2009 at Apple Store, Liverpool One (only 18 months ago but out of warranty and no AppleCare).

I've had a blissful time with it, extolling its virtues to my friends who have PCs. I use it a lot for photo editing with Aperture. Whilst showing one of these friends some pictures in full-screen mode of a recent trip we took, we both noticed a series of grey smudges in the top-left corner of the picture. I at first thought it may have been dirt on my camera sensor, but it would have to have been the almightiest of sensor fouling as it covered ~3" square of screen! Anyway, I tried the usual things like powering down and back up again, however still the same pattern of smudges. Tried taking off (carefully) the front plastic panel and cleaning both it and the LCD underneath, to no avail. It has now dawned on me that it can be nothing but the LCD. I noticed that it has occurred in a place spot on the screen where there's a fair bit of heat being generated behind - could be a cause? It is extremely distracting when I'm working to have this catching my eye in the corner of the screen.

I'm in a position now where my nice machine which I've been bragging about could now be failing in the display department. I've really looked after it as well, powering down when I don't use it, it's in a place away from humidity and direct sunlight etc. I'm just hoping now that it doesn't get any worse, as I know what the likely response from Apple would be - "not under warranty, go away".

Add me to the list...

27" model from Nov 2009 production line.

Developed the greyish smudge marks along the top of the screen -- apple replaced it no questions asked.

6months later, same problem.

<Edited by Host>

You can remove the plastic screen yourself with screen suction cups. It's only held on by magnets and can be easily taken off, cleaned and placed back on your monitor. If that doesnt solve the problem, take it back

Christopher clearly underestimates mental capacities of participants of this thread! =)

Anyway, I opened up my iMac to find this - http://www.youtube.com/watch?v=DkmnOcZYARk

That whitish deposit is NOT DUST from the environment, it is clearly some kind of internal build-up coming from within the machine! I bet what we see on our LCDs is the same or some similar substance.

same problem here, in indonesia, waiting for apple answer about that

There are other fixes out there. Remove the front panel, then unscrew the glass panel attached to lcd screen and then clean the glass and use a sticky roller or compressed air to remove dust off of lcd screen. Do not wipe dust of exposed lcd screen. The problem is with some imacs not having properly sealed glass over the lcd screens. The fan in the back ***** dust into the monitor, and if not sealed properly will actually get between the screwed glass panel and the lcd screen. This creates the smudge look. Open an old computer and you will see all that dust inside. Over time, dust like that will get inside your imac, and if the screen is not sealed properly will cause problems. Unfortunately, this is a problem with one piece monitor/computers.

Clarification: The spots I am experiencing are not on the glass or the front of the actual LCD panel. They can not be cleaned off. Mine seem to be trapped in between the LCD and backlight.