Greyish Smudge marks behind the glass screen.

"I'm sure they've probably ironed out all the problems in the new machine by completely re-designing the hardware."

I don't think they've fixed anything. They're just not interested. I won't buy another Apple machine - too unreliable and too much hassle. This wall of silence from them is just ridiculous.

I don't know if you've ever looked inside one of these computers, but half the components are put in place with cheap looking sticky pads and what amounts to copious amounts of self-adhesive tape - it's all very low rent. Nothing is properly sealed and the airflow is practically non-existent unless you whack up the fan speeds.

You know it's bad when you see machines in your local Apple store with the same smudge problem.

I bet 2010 iMac buyers were thinking (hoping) the same thing about Apple fixing the problems from the 2009 models, and I bet 2011 iMac buyers were in the same boat from 2010 models, and 2012 iMac buyers were... you get the idea.

That being said, and recognizing the pattern of the last 4+ years of iMac screen issues... I, too, am hopeful that the rumored "total redesign" of the (presumably) "late-2012 iMac" will finally bring an end to these screen issues. I base that hope largely on the fact that some rumors point to the lack of an optical drive... if they're doing away with that hardware I reeeeeaaally hope it either improves air circulation or they can add/shift other components to alleviate the problems we've been experiencing with our iMacs. Then again, if they are going to make the iMac screens even thinner, maybe that will only lead to bigger heat issues with the "guts" of the machine pressed even closer to the LCD panel.

Fortunately my AppleCare runs through the end of 2013 on my current iMac, maybe that will be enough time to guage buyers' feedback and see if the yet-to-be-released models have the fix we've all been waiting for...

Well, relatively speaking, the 2009 iMac is the same design as the 2011 version with upgraded internals, so no, I wouldn't expect the screen issues would magically cease. These rumored new iMacs are supposed to be completely re-designed.

You're right though, if they try to make the iMac thinner, these issues might likely crop up again, unless they've created better shielding or air circulation.

All of the iMacs from 2009-2011 seem to have these screen issues sooner or later, so that's an awfully large group of people that might want Apple to provide some sort of trade-in program. If it was just one bad model like just the 2009 version, I'd doubt there would be a chance, but since it covered the span of 3-4 years, I think they might have to do something...just optimistcally speaking I guess.

As long as it says 'Made in China' I think we know what to expect - more of the same. What is strange though is why so many people are willing to give Apple the benefit of the doubt.

How many chances do you give them?

Trust me, if I didn't like the OS so much, I'd probably switch. I don't like the UI design of Windows or Linux. Although, a hackintosh is certainly an option, but upgrading Mac OS X is a lot more of a hassle when using your own hardware.

I do still like the Macbook Pros though and was lucky enough to inherit a 30" Cinema Display. So, I use the iMac as a backup machine, but it was about a $2k machine and had a hard drive failure in the first 2 weeks of owning it. It also has a yellow tinge on the bottom third of the screen and smudge marks appear along the right side of the screen when it's used for heavy graphics processing like Photoshop CS6 or StarCraft II.

These 2009-2011 iMacs that have been the worst designed Macs ever.

There are several actions being taken online if you google the same subject. I'll probably get deleted here, but subscribe to this thread and get email notifications. That way you will see links that are posted and then taken down by Apple. My twitter is @Omek.

and this is not something with dirt under the glass as I was hoping for a second? 😟((( I am not technically strong, so do appologise for stupid questions..... is this something with the screen? What people do with this damages?

I may have been lucky, but Apple replaced my LCD panel a couple of months ago on an iMac that was just over a year out of its warranty. May depend on who you can get hold of at Apple when you contact them. I'm in the UK by the way.

it's certainly not universal response...can't get mine even acknowledged here in New Zealand/Australia...startd when living in India and they said environmntal ...sorryYashik...not fixable...even when screen replaced frequently seems to comes back...you'll find all sorts of experiences from Apple support recorded here...Australian/NZ say won't replace after expired warranty..go immediately to warranty support before expires...you may be lucky!

There's not a conesus to whether this is dirt or not. The screen doesn't seem to be properly sealed. However, I think it's more a of a problem of the LCD being too close to the internal hardware. As the machine gets used for more intense tasks, things heat up and cause some of the cells in the LCD to burst, hence creating the smudge-like effect. That sounds like the most plausible explanation to me, but it could also be dirt and dust getting sucked into the back of the monitor, because it's not properly sealed. It's really hard to say.

An explanation from Apple would be nice, but we still haven't gotten one yet.

You can go to your nearest Apple Store or Apple reseller and see what they can do, but I've seen most screen replacments have been a temporary fix. The hardware design seems to be the flaw, so it's going to require a complete overhaul of the entire machine.

I don't know it its LCD bubbles bursting - in my case it could flare up, and calm down, usually depending on heat. Plus it would shift a bit - usually it was a jagged line, but sometimes perfectly straight.

having experienced this - and observed the process - (I'm not expert - but have used macs since the mid 90;s) - It seems to be a 'heat' issue. My brand new mid 2011 imac was the 'hottest' computer I'd ever owned. I would wake up in the morning, and go into my living room and wonder why it was so warm. (bearing in mind I live in London, UK).

First of all the hard drive failed after about 6 months, and I just thought - 'these things happen'. Though I was still concerned about the heat it was pumping out - but still just thought it was how 'new' Imacs were.

Then occasionally the imac would randomly put it the 'screen' to sleep. (not the whole system, as processes were still happening in the background and I could hear the drives running.) This became more frequent - and was the initial reason I contacted apple again (11 days out of warranty) to get it fixed.

I hadn't even noticed the discolouration of the screen until I was waiting in the apple store in Brent Cross (under it's bright fluorescent light) waiting to speak to them about why I'd contacted them. The 'smudging' was mainly contained to the upper left quarter of my 27" screen - but also seemed to have 'spread' down most of the left hand side of the screen, too. Apple called this 'contamination' (and made me feel as though it was 'my fault' and they would fix it 'as a favour'.) I wasn't impressed with the service (for the first time in 20 years).

However - since they have replaced the Power Supply, LDC Panel with BLC and Glass panel - all seems to be working fine. The imac is nowhere near as hot as it used to be - even when I'm running processor intensive apps.

I didn't break it, Apple. It was broke already.

The heat affects the polariser layer in the LCD screen - as a result areas of the screen take on a smudged/stained appearance.

There isn't any dirt (in my case anyway).

After a load of silly excuses from Apple I took my 2011 iMac apart to verify this.

oh -- i forgot to mention that the only way i could 'bring the screen back to life' (when it randomly went blank) was to actually put the machine to sleep by pressing the main power button once. Wait for the imac to actually 'sleep' and then 'wake it' as usual, but pressing the space bar or something, All the things I was working on etc - were exactly how they were. not sure if that helps anyone. just saying. 😉

To Packjoker:

There's a very thin ribbon data cable that links the screen to the main board, this can easily come loose. It's the ZIF type with the latch. By contrast the cable which powers the backlight seems reasonably secure.