Greyish Smudge marks behind the glass screen.

Same problem here. I always thought the screen of my iMac 21.5 (bought October 2009) looked a bit yellowish, but a couple of months ago I started noticing these stains on the upper left corner of the screen (especially visible against light uniform backgrounds). The spot is about 12cm wide by 8cm tall. I took some pictures using an all-white backgroung as screensaver. You can see the pictures here: http://gallery.me.com/pedrocmonteiro#100102
(the color changes are the result of me trying to find the right camera settings for taking photos of a white screen...)
I'm going to try to solve this with Apple while the warranty is still valid.

So I have had this problem multiple times with more than one iMac eventually getting replacements secondary to the costs of continual lcd's replacements- Only to have it reappear albeit on different areas of each screen and each replacement iMac. I understand the logic behind blaming environmental causes but I do not smoke, rarely if ever cook, have good ventilation, keep the windows closed often, etc. For a while I was grateful receiving the newest incarnation iMacs to replace 2 of them after each had lcd's replaced more than once each. But another call! and the defensiveness generated by having my environment scapegoated. Sheesh....dennis (NYC)

Count me as another one. 27 inch bought December 09, has the gray-brown smudge in the upper right. Getting slowly worse. I did not get Applecare, and this does not interfere with function, so just have to live with it for now I guess.

OK, same here with my 24 inch iMac (Early 2009, bought August 2009). So I called Apple and they sent me to the apple genius. They replaced the LCD-screen in warranty. Now 2 months later, the problem is back. I called Apple again today. Now they claim it is the Video Card (NVIDIA GeForce GT 130), but she could not confirm that the card is the problem. I have to bring it first to apple genius again!

Keep you posted....

Yes - this is well known problem and MAC replace the LED every time - but I see a blogger on the web who took the screen off the front screen and discovered that there is a sheet of plastic which is sitting into of the LED.

This sheet of plastic is touching the led and is sticking to it.

He took took it off..... but I am not doing that!

If you press the area with your thumb you can see the plastic move slightly and the mark changes. So he sounds like he has discovered the problem.

problem is changing the led doesn't sound like a permanent cure.

Only do this yourself if you don't care about you MAC - it nullifies the warranty.

Hi austenlennon,

I hope you don't mind if you could share the URL of the blog you were talking about?

After a visit to the Apple genius, I've got a new lcd now. I hope the smudge marks will stay away now...

Hello everybody (and sorry for my english)

I live in Parma, northern Italy. I am a Mac user for over 15 years, and now I have an iMac 21.5 ", purchased in December 2009. After a couple of months have begun gray spots in the upper left corner. I removed the glass panel and the spots were actually inside the display. I read this post, and others, to know whether it was a widespread problem.

So in late August I called Apple support service – yes, I waited a lot, but at some point the spots gave much annoying! - I just explained the problem and the girl, very friendly, put me on hold for the arrival of the new display. Result: this morning the operator of the service company came to my house, out of their HQ in Milan (70 miles) and replaced the panel in half an hour!

What can I say? Thanks Apple!
(and thanks Google translator)

PS: I have Apple Care, but the iMac is still in the first year warranty

I purchased my 24" iMac in Jan 2009. 3 months later greyish smudges appeared on the screen sent the machine and had the screen changed. 3 months later same thing. Then in August 2009, they sent me a new iMac, but 3 months later the similar smudges appeared on the screen once again. for the next year I had been sending in the machine in to get this sorted out.

My last experience with Apple Asia is that they are washing their hands of my screen issues. Citing "environmental" conditions. They even had the nerve to tell me that this is the first time that they are hearing of a case like mine.

I think they should come here and read this thread and other similar threads.

As far as I am concerned this is NOT and isolated incident and it has nothing to do with the environment after reading this thread and, I guess, there are other threads around with people complaining about this issue.

Common Apple Asia, get your act together!

This is a previous thread on the iMac screens.

http://discussions.apple.com/message.jspa?messageID=11511204#11511204

My iMac 27" (Late 2009) started showing up these same greyish smudges on the screen after about 4-5 months of use. I decided not to do anything about it until last week when I wasn't quite so busy.

The machine went off to one of Apples Authorised Repair centers (Am Sys) in London. They took a look at the machine and said yep we will just swap out the screen, should be back with me tomorrow.

Am hoping the replacement screen is one of the new batch which ship with the new iMac series as as far as I can tell they seem to be more reliable.

I just bought an i7, set it up and turned it on. Immediately noticed a grey line or mark on top left hand corner. It looks like it is behind the glass. Brand new computer, and has a defect??? I was so excited to finally get this computer of my dreams, and now this. very unhappy about it.
What are my choices?

Same problem here. Bought January 2010 my iMac 21.5" (Late 2009). Started showing up these same greyish smudges on the screen upper left corner, after about 4-5 months of use. Apple replaced the TFT panel. Now 5-6 month later the same problem again. And I do not smoke. Today i got my iMac back from Apple with a new TFT panel.

It seems to be a problem of (Late 2009) iMac´s.

I have found this problem description in German, English and Danish Apple forums.
So it is a European, or maybe a worldwide problem ?!?!

Hi everyone, I have the same problem with my imac after some months of use I see on my top left side of the screen some brown smudges behind the screen which is very annoying to my as a photographer. The other problem I got is that I purchased my imac in a local electronic store since we in Tirana, Albania do not have an apple authorized store.
Is it safe to self-open the screen as some sugest on Youtube?
I will appreciate your feedback...

thanks, Armand

I have had three screens replaced on my 24" iMac. The engineer who came today said it is a VERY common ocurrence and may have to do with the computer heating up behind the screen in different places. I am a photographer and this is unacceptable. Sadly, it is clear that the configuration of the LCD with the computer behind it what is at fault. So it is a big amount of money down the drain.