I own a Macbook Pro, Macbook, iPad 2, (2) iPod Classics, an iPod Touch and an iPhone 4S. This problem hasn't appeared on any of those devices. Nor would it; the LCD panel on a laptop is completely separated from the heat-generating components of the product.
I had a Cinema Display and never had this problem. However, that also lacks the built-in computer components of an iMac. A Cinema Display is just a monitor.
To me, it is quite clear why this problem only effects iMacs: because the iMac's computer components are in direct proximity to an LCD panel that doesn't react well to high temperatures.
This thread has grown too large for me to search through, but at some point these images were either posted or linked:
Specifically this one:
And as you can clearly see, this person is wiping it off and "solves" his problem. It's important to note just how involved this "fix" is... the average user is probably not going to go this route! And neither would I as long as my machine is still under warranty.
Hopefully you didn't confuse my post as defending Apple's handling of this situation... I'm in the same boat as everyone else here and I have to decide whether to live with my smudge marks or continue to get my machine serviced every few months! My only point is that the person from the links posted above is able to clean the internals of his machine. From your engineer's description, and from your most recent response, I would be surprised if that kind of LCD damage was "cleanable".
That's exactly what I'm assuming as well. I have the original late 2009 quad-core i5 iMac, and the staining just started happening. I tolerated the 1/3rd yellow tinge on the bottom, but this is just getting ridculous. This machine has had so many issues.
We also have an ipad, and it doesn't have any of these issues.
I did hear that some people where noticing the same yellow tinge on the lower 1/3rd of the 27" Cinema display that is also prevelant in iMacs. But, I'm still not sure if that issue is heat-related or not.
Apple clearly must be aware of this stain issue, but they just don't want to do a recall. And like your friend said, probably the only thing that is going to solve this problem is if Apple redesigns the iMac. I'm thinking the best solution for now may be to sell or trade-in for a Macbook Pro or mini with an external monitor. I think this problematic iMac is just going to get worse and worse. The longer Apple waits to recall this iMac, the worse the aftermath will be.
Binary Mango -
The image you posted is of dust. Notice that it looks like...dust. Not water. Dust.
The images posted by 99% of the people on this thread looks like water. Hence the reference to a "smudge" or "water stain."
Here is a link from the second page of this thread:
I'm not sure why I feel like we're arguing over this; maybe it's because you believe with 100% certainty what your engineer told you, and that's fine. But honestly I believe that the "dust / stains / smudges" are in fact all part of the same problem, just described differently by different people.
Have you taken a close look at the "dust" in this one photo?
Do you see how it looks splotchy/smudgy? I could absolutely see how some people would confuse this for a water stain. In fact, look at the first comment from user "iammike1" on top of the thread I posted before:
He writes: "Mine wasn't dust. Was kinda difficult to wipe off. Almost reminded me of water stains which I guess could be possible if condensation got in between the panels."
So, I'm not saying it's dust, it might be some fine particle from something that was melted/separated inside the display as a result of the heat. But what I am saying is that people are able to wipe this off, albeit not always easily. My point in all of this; the "moderate" cases I've seen do not appear to be permanent damage to the LCD's but are clearly beyond the ability of an average user to clean, and will void an active Apple warranty if the screen is disassembled anyway. That's a far cry (to me) from what the kind of damage your engineer was describing.
I'd appreciate a little less condescending tone if you'd like to continue this discussion. I'm not the enemy here, nor am I a child or a complete stranger to the problem that has been plauging my iMacs for the last year or so.
Binary Mango -
And yes, I was defensive because you came across like a shill for Apple. Perhaps starting with "I have a similar problem with my iMac" would have helped. In addition, the references you have are for a completely different thread!
I come from a place called Rational Land. We do things differently there. First, when we cite sources. Second, when we say a thread has "all sorts of examples" we don't assume other people are mind readers allowing us to refer to a completely different thread. For example, if I'd seen the thread you were referencing I might have been less defensive and given you some credit; that thread and the detailed photos are quite useful. Based on that series of photos it is entirely possible some people on this thread have a dust problem instead of a heat problem.
Now that we're back on track I think it is fair to say that whether someone has so much dust in their LCD panel that it is creating streaks or that heat buildup has caused wet-looking smudges on their LCD panel that both are unacceptable design flaws of the iMac.
Computers should not be disposable goods. With these flaws the iMac most definitely is.
First, I've been following this thread for a while and posted more than a couple times about my personal iMac "screen smudge" experiences so I hope you can understand why I wouldn't continue to preface every comment I make with "I'm having this problem too!" when I've already said it in the past. Understandably there are newcomers to this thread and the fact that it's 30+ pages long doesn't help things!
Which leads to my second point; as for being a mind reader, I guess I just assumed that someone who posts in this thread would be familiar with its past postings:
Jun 20: https://discussions.apple.com/message/15447914#15447914 (from me!)
And another post back on Feb 24 from user "Controllo" which also references the other macrumors post (I keep getting an error when I try to link to that one... it's towards the bottom of Page 11 if you're that interested)
Bottom line; these were posted in this thread and nobody was expecting you to be a mind reader.
Glad we've cleared the air, but again it's comments like "Rational Land" that might drive your point home but they do it in a very condescending manner.
I agree with your final point, these are expensive machines and it's not unreasonable that we expect them to work.
I cant believe the amount of people with this problem. I thought I was the only one. I don't know how long it's been there but I just noticed it. It looks like a black smear in my corner. Driving me nuts! They said it is out of warranty and it's an enviromental problem. Give me a break. Last Apple product I ever buy.
If you have a problem with your product just admit it.
If you haven't already, be sure and check out the first search result in this Google link:
Welcome to the club!
I've had many different mac's over the years... 3 different imacs are amoung them. I can tell you that all three imacs were affected by the smudges and yellowing. My current imac also has this problem. I can also tell you from experience IT IS DUST inside the display. On 2 of my previous imacs I actuall took the screen off... split it in half to get between the LCD and the other reflector's and polorizers. I did infact manage to clean them off and restore the screen to no smudges... HOWEVER this is not for the inexperienced. And if the screen has been "warm" then the connections on the surface mount ribbon's are brittle and you will develop lines and missing pixels in your screen if you bend the ribbon's taking the screen apart. I also have noticed the ribbed reflector which is made of a white plastic was yellowed by heat. I was unable to completely remove the yellowing. However, that stuff that you use to polish headlight lenses on cars mostly did the trick removing the oxidation. The bottom line is that the fans draw dirty air into the display because the edges are not completely air tight. The stand alone displays do not exhibit this problem because they are not vented with fans. When re-assembling the screen if you get even 1 piece of dust between the reflectors and the LCD it will drive you insane.... This whole process shold be done in a clean room.... All it takes is one day to cook with grease and that stuff get's inside your machine and then being sticky... the grime builds up.....Usually becomes noticible during the second or third year depending on how much you use your machine. I use mine ALOT they're nearly on 24x7 so they develop the smudges quickly even though our home is cleaner than most.
Welcome to the club folks... just ebay your imac every couple years and you'll be fine... they do have a decent re-sale.
I have same problem with my iMac27,and I was at the apple store yesterday,to see what they can do for me.But they didnt do anything,he just look at my warenty,which already expired and he gave me really short and stupid answer.They told me that stains are from cigarets,and that I shouldnt smoke in room where is my mac,and that was all,he didnt want to talk about that anymore.So I turned around and walked away.Today I called apple phone support,first he told me that I dont qualify for phone support,and that I have to pay $49 first,but he was a good person and he asked me what is my problem,after me explaning him about stains,he said that there is nothing that he can help me anyways.So ...............
You have to keep your Imac in Seal-Tight closed,and probably work from there,and use buzz lightyear costume
just find your size
http://www.google.com/search?q=lightyear+costume&hl=en&source=lnms&ei=QObvTvHVJI H30gGV-JXtCQ&sa=X&oi=mode_link&ct=mode&cd=1&ved=0CC4Q_AUoAA&biw=2560&bih=1342#q= lightyear+costume&hl=en&sa=X&prmd=imvns&source=univ&tbm=shop&tbo=u&ei=RObvTsWKLo ba0QHS2KGvCQ&ved=0CFAQrQQ&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=a2966a2c49d768a8&biw= 2560&bih=1342
oy vey this is a big conversation! The grey shadowing/smudging is neither dust nor water most of the time. These are pressure spots. To put it simply the layers that make up the screen get pushed together which results in those marks.
Typically all you have to do is remove the screen with a suction cup(s) (it's held in by magnets) then put it back. Now look at your screen. Spots should be gone.
Do not attempt this with a toilet plunger.
BTW - I disagree that buying a refurb Mac from Apple is a bad idea. It's a fabulous idea. It's basically a new computer. Any problems you might be having with a refurb are most likely nothing to do with the fact that it is a refurb.