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Okay just an update guys. I sent my 27 inch iMac to an official Apple Service Center for repair. The local repair center sent the case description and photos to Apple Asia and it was rejected for warranty repair. The techs at Apple Asia reasoned that it was caused by (you guessed it!) "Environmental Problems such as smoking, extreme humidity etc" which I dispute because, as I said in my other post, not only is our office clean, smoke free and air conditioned 24 hours a day, but in the very same office are older Aluminum iMacs that have been there way before my 27 inch but never developed any screen issues. So I had to call the Asia Applecare hotline to politely ask them to reconsider my repair. They told me that they will review the issue and get back to me in a day or so.

Any follow-up to your situation?
 
Apple really surprises me on this one. Actually there are many, many Graphic-artists and photographers all over the globe using the iMac-27, just for the sake of the screen ( Im being one of them).
I had to change mine 3 times as well, luckily I also have an Eizo monitor but still.
All I can say is, once you get a shall we say 90% perfect sample, it is in fact a joy to work with and the screen itself is really good.

So whats the next problem on the agenda? burnt out logicboards? explosions?
 
Having the same problem with my 21.5" that is about 2 months old. Started noticing the problem about a month after purchase. I'm in Tokyo but it's only now starting to get warm so humidity isn't a factor yet.

Really frustrating and my MBP is perfectly fine despite being taken outdoors repeatedly since last August in Tokyo.

Really don't want to have to take this to an Apple Store. Closest one is about an hour on the train not to mention all the actual carrying of the box between the station and destinations.
 
hey guys

I just noticed a similiar problem on my imac 27 inch last night. I see a little bloch of it in the upper right hand corner. It seems like a lot of other people are getting it in the same corner. What components are behind that corner? CPU? GPU?

I usually don't put a white background up or a window with a white background at that spot so haven't noticed it but I'm sure it wasn't there a week ago. The only thing different I've been doing is playing TF2. So perhaps it is related to some sort of overheating?

Should I be calling Applecare now or wait until it gets worse?
 
Watch out for those candles!

Hello all,

I had the same issue on both sides of the screen on my 27 inch. Took the iMac back to the Apple store in Brandon, FL. and they decided to just replace the display panel. I watched the genius take the screen cover off and attempt to wipe away the spots. That's when we realized the issue wasn't on the surface of the panel. Just went to pickup my iMac today and its fixed......for now.

The reason why I am posting my experience here is because of what the genius told me via voicemail. This guy had the balls to tell me he smelled a candle inside of the iMac and that's the reason the black spots appeared. Like I would really place an open flame near my $2000 investment on a solid glass desk! Then goes on to say that they performed the replacement and the next time Apple Care wouldn't cover it. I smell bull$h1t! I understand defending your product's reputation, but that's absurd. I told the nice lady that brought out my iMac, but I couldn't remember the fools name and I deleted his message. I guess the rest of you must have a candle lit under your iMacs as well. LOL! I'm a systems admin and I specialize in hardware, but that's one I've never heard nor seen. If you have this issue and live near Brandon, FL. be warned.
:mad:
 
Black spots usually appear
when iMac is used for gaming or CPU and GPU intensive applications.

Older macs have the same problem.

Do you play games on iMac?
 
Black spots usually appear
when iMac is used for gaming or CPU and GPU intensive applications.

Older macs have the same problem.

Do you play games on iMac?

yes i do... so if that's the case should i just keep using mine since i bought apple care and once it gets worse i'll swap it? no point in keep swapping or replacing panels if i can live with it?
 
yes i do... so if that's the case should i just keep using mine since i bought apple care and once it gets worse i'll swap it? no point in keep swapping or replacing panels if i can live with it?

You should have went with i5, it produces 10°C less heat.

Yes, continue playing. But, in three years, when they replace for the last time, you will have to stop playing if you want to continue using your mac.


That is sad. Steam came for mac and macs are not designed to handle any heat.

I have a separate Windows machine for gaming.

Downlaod smcFanControl (google). You can regulate fan speed with it.
Be careful, if you turn up the fans all the way up, it will be very loud and it takes a few minutes! time to lower the speed of fans.

And google "Temperature monitor mac", download (from macupdate), start some CPU intensive app and look at temperatures.


To everyone

PEOPLE STOP PLAYING GAMES ON MACS AND STOP RENDERING ON MAC

they are NOT designed for it. Macs have the worst cooling system a computer can have. I have a i7 860 Windows desktop with Noctua U12 cooler and MAXIMUM temp under full load with Lynx it is 55°C, while i7 860 macs go all the way up to 90°C.

We should really sue Apple. It is not hard to make a better coolling system....

I have a i5 iMac, so I don't know how hot i7 is. But it must be much hotter than i5 (76°C) because of HyperThreading.

Playing games on iMac is like shooting with rifle at fighter jets...
 
so basically these are burn marks from overheating then?

would not playing games or doing GPU/CPU intensive activities make the dark spots disappear?

I'm still a little confused at where the spots actually is. Is it on the underside of the glass or actually on the LCD panel itself?
 
so basically these are burn marks from overheating then?

would not playing games or doing GPU/CPU intensive activities make the dark spots disappear?

I'm still a little confused at where the spots actually is. Is it on the underside of the glass or actually on the LCD panel itself?

No, they do not disappear and you can't wipe them off. I know, it is a disappointment, but the problem is as old as iMacs. There are many threads with the first Alu iMacs from 2007 having these problems.

The heat damaged the screen from behind. I don't know which layer is affected as the heat can easily travel through molecules. It is the actual Screen that is affected.

There is always a possibility that it is something else other than heat. But 99% it is heat, as it was the case on the older Alu iMacs.

Just make sure you extend Apple care, before the 1 year warranty is up.


Upper right corner: Grafics Card Heat. Left to the SuperDriver there is a Square. This is the graphics card. The heat pipes lead the cooler in the top right. The air blows from the bottom right up right and leaves the case through the opening in the back (you can see it as a line on the top in the back of your iMac)



You can touch the upper right corner Alumnium and feel the heat when u r playing. Sadly, engineers at Apple don't seem to be that smart. I am not an engineer but I have an understanding of that the iMacs have very poor inner design to transfer heat. The laptops also have poor cooling. I had 3 macbook pro laptops that died on me (during gaming of course^^ two of them during Left4Dead :D ) But Apple care rules of course.

Poor engineering leads apple to higher investment cost through problems, however not lower stock price, as large investors always get rich on those who suffer :p
They should employ me, and all heat problems will be gone :p
 
To everyone

PEOPLE STOP PLAYING GAMES ON MACS AND STOP RENDERING ON MAC

they are NOT designed for it. Macs have the worst cooling system a computer can have. I have a i7 860 Windows desktop with Noctua U12 cooler and MAXIMUM temp under full load with Lynx it is 55°C, while i7 860 macs go all the way up to 90°C.

We should really sue Apple. It is not hard to make a better coolling system....

I have a i5 iMac, so I don't know how hot i7 is. But it must be much hotter than i5 (76°C) because of HyperThreading.

Playing games on iMac is like shooting with rifle at fighter jets...

Well for one you're stating the obvious. The design of the iMac does have its limitations when compared to a tower with all sorts of space for airflow inside of it, and space for really big heat spreaders. The dark spots seems more of an isolated problem, it could have been caused by some computers being built less effectively than others-- bad application of thermal paste could be one reason. I've had my i7 iMac for months now, and have underwent hours upon hours of intensive video encoding that maxes out the cpu the whole time. The temp of my i7 never got above 69c before fans started kicking in, and it only took the cpu fan going from 940rpm to 1300 rpm for the cpu to be cooled down to under 60c again. The i7 also idles at 39c on my iMac. I've played demanding games like dirt2 and starcraft2 on the iMac, the gpu has gone up to 75c, but never higher. You can even rev the optical drive fan up to 2-3k rpm and the gpu will never go above 60c.

So I for one don't appreciate acting as if the new iMacs are ticking time bombs, because they're designed well for what Apple chose to limit them as. They run warmer to other computers because of their slim case and really low fan rpms-- Apple choses quiet computers over ultra cool computers. That doesn't mean they're bad on the cooling department though. Keeping internal parts below 30c all the time is fine and dandy, but doesn't really improve lifetime expectancy. Temps of 80c or below for gpu and 70c or below for cpu are perfectly within normal operating temperatures, and you could force them to stay well below that if you forced the fan rpms up to speeds you'd normally see on PC rigs. The new iMacs have pretty good cooling performance, no reason to declare jihad against Apple for the occasional lemons they produce, such as the ones in this thread that are experiencing burn marks on their screens.
 
It is sad Apple pushes for thinner design. I don't think it would be a problem for an iMac to be thicker. It may even get more stylish, if it did not have that curve in the back. They could have put a bigger cooler, bigger fans, maybe even 120mm fans and so avoid all the problems that people are going to have very very soon.

I am sure soon the graphics cards will begin to fail, screen stains, maybe a cheap DVDs get melted in the SuperDriver.

Video encoding is not as CPU demanding as Rendering (even though the Activity Monitor shows 100%, it is still not 100%). But I think the CPU is not as a big of a problem as GPU. CPU+GPU running together at max at the same time is of course dangerous.

On my old 20 inch I put Arctic Cooling MX2 Thermal paste instead of that white foamy stuff they put in there and temps imrpoved significantly. The only problem for me was to put the glass panel back on without leaving dust behind it.

By the way 70 is maximum what Intel recommends for i7.

I do not agree with you about "pretty good cooling performance" as this "perfomrance" is the worst!!! on the market. I like macs a lot (mainly because of OSX and Final Cut and User experience), but I don't like the hardware.

Where do you live? It gets very hot in Los Angeles in summer...

My temps on my windows machine i7 @ 4000mhz using lynx. I will never reach these temps (of max 66) using normal programs. This was done with Linpak Lynx. Unoverclocked it runs 55°C with Lynx and about 52° when rendering. The other coolest sample I had was 49°C on one core and other 48 47 46 under full load.
(the screen is from hardwareluxx.de its my screen)

And actually, the coolness is proportional to noise. My PC is more silent than iMac, even when rendering.


For your own sake, use smcFanControl. Raise rpm to the level you don't hear and be happy. I always turn up rpm more before gaming, just to avoid these spots. And yes, they are from heat!

It is a nice machine! I mean, there is a reason i bought it. Except of course that the magic mouse sucks for mudbox or maya or anything else :p I mainly use wacom tablet though
 
Fungal Marks?

Here are the marks developing on a weekly basis on the left top side and on the right top side.

Seems to be spreading like a fungus or something similar it is within the LCD itself not the glass. (Glass removed by service centre to check).

Service centre stated they need photograph it and send to Apple to check if it is ok to replace under warranty (5 month old machine).

However they said unlikely as they have had a few like this and Apple has refused the warranty claim saying it's due to the environment i use the machine in...

Which is nonsense its a brand new condo with climate control air conditioning and why is it my Macbook Pro, and my other imac 27" does not have this problem then both of which have been in the same room and therefore environment longer than this new imac 27".

Feel I will have a battle on my hands.

[URL=http://img215.imageshack.us/i/photovji.jpg/]

Uploaded with ImageShack.us[/URL]
 
I'm facing the same problem :mad:
they told me they will change it
but I'm afraid it will return back after fixing it
if anyone fixed it,did it show up again?
 
I have the exact same issue. Started noticing a week ago. Got my 27" i5 Imac around Aug, so just about 2 months old. Will it get worse?
 
iMac grey patches and spots on screen,a greek tragedy with tragic greek Apple support

I ve experienced the same screen problems like everyone else here. However I would like to report that the official service provider, named System Graph EPE, for Apple in Athens, Greece where I live totally refuse to replace faulty units. In my case, I brought my 27" intel iMac in their service, they replaced the lcd panel inside with another faulty panel! I complained in writting and I was literally kicked out from their store when I visited a second time!!! The man in charged bullied me by saying "take it and go somewhere else".
Mind, that consumer law in Greece, dictates in specific that the customer has a clear choice to request a refund, replcament or repair while under warranty for any faulty product after initial repair. This is what Apple after-sales services look like in Greece at the moment.
I am now in the middle of a legal dispute and the company that imports apple products, namely iSquare, is doing their best to avoid a refund or replacement. Of course, no word about ethical reimbursement of any kind for the delays or the treatment I received at System Graph. Makes you feel they are doing you a favour they sell you Apple and talking to you! Apple consumers in Greece are simply.. insignificant for Apple.
 
I have the exact same issue. Started noticing a week ago. Got my 27" i5 Imac around Aug, so just about 2 months old. Will it get worse?


In my close to 40 years and in the last 30 of buying electronics, Ive never seen a defect get better. Only worse. Id get a refund or a refund/replacement. Apple is selling off their bad inventory, I think. You should get a newer manufactured one. Be careful, some who have bought NEW iMacs end up with refurbished replacements. It is best to return and get a full refund, in lieu of a repalcement which will be refurbished. It defeats the point of buying "new," and not refurbished from the get-go.

Anyway...


The real question is... WHY HASNT APPLE FIXED THIS???
 
okay everyone - I got somewhat of an answer for you from a senior tech rep at apple. He said the problem is related to condensation on the panel which develops when you power down the system. Basically he told me that the computer needs to keep warm i.e. stay on all the time. Set the energy preferences to never let the system sleep and put the screen saver on. You can set the display to sleep but not the system. FYI, I have a dual monitor imac setup and my other monitor is the dell U2711 which uses the same panel as the 27 imac. I've NEVER had a problem with it - it's an amazing monitor.

I'm on my second black-spot screen, getting my 3rd panel this week. Applecare is a must for those getting this imac, because of the door to door tech service. Lugging this beast around is no good.

Cheers
 
okay everyone - I got somewhat of an answer for you from a senior tech rep at apple. He said the problem is related to condensation on the panel which develops when you power down the system. Basically he told me that the computer needs to keep warm i.e. stay on all the time. Set the energy preferences to never let the system sleep and put the screen saver on. You can set the display to sleep but not the system. FYI, I have a dual monitor imac setup and my other monitor is the dell U2711 which uses the same panel as the 27 imac. I've NEVER had a problem with it - it's an amazing monitor.
Cheers

My imac 27" is running pretty much 24/7 and the black spots began to appear a few weeks ago. Took it to the apple store last night and genius said they would replace the LCD (5-7 turnaround). He implied that it is due to a smoking environment...well, not in my house. Will report back when LCD is replaced.
 
Hello, everyone. I just registered at MacRumors to take part in the discussion.

My story is roughly the same as yours:

bought an iMac 27" in January this year, 3.06 GHz Core 2 Duo. Don't actually remember when, I started noticing these stains, and in August they covered half the screen so I brought the computer to the Apple Store and a technician replaced the display with a brand new one.

Two months ago the stains started to reappear. I called to inform of the situation and next week I'm buying the AppleCare Protection Plan since the black spots (small area at the moment, nonetheless visible) seem to be getting bigger once again.

It's really annoying.

The best part is that I was on the phone with the technician last week and I told him I had read many people on the web complaining of the same problem my iMac is having, to which he said that he had never had anybody came back a second time to have the screen replaced, and that on the web you can find "just about anything"!

I wasn't pleased as you can imagine.

I plan to go to the store next week, buy the freaking, 180-euros AppleCare and start to raise my voice a bit. Replacing the display again would be dumb, the issue would represent itself, I want the entire computer replaced this time.
 
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"Blotches, Spots" here as well - 3 Month old iMac 27in

The spots, dark blotches are on mine as well..and growing as of Dec 12th, 2010 Only 3 month old (since i purchased it) - iMac 27 inch QuadCore. My 1st Mac since 1999

Smoke free environment. No gaming, but I do use Adobe CS5, some audio/video editing. Now if that is the cause to overheat the fan and 'burn' the screen. - In some occations from what I read, repeat burning of the repaired/new replacement LCD screen What's the point of me owning this?

Also from my readings, this has been an ongoing problem for well over a year - looks like it hasnt been solved, obviously upgraded when the new iMac came out in July?

Look..no complaints, other than this monitor flaw many are having, this is a great fast computer, I love it..but man this is deflating.

I'll be calling Apple, schedule an appt. to fix this tomorrow.

For the ones that did get this fixed...(Since I am new to this repair thing, Apple Care) how long is a repair job like this take? Any new issues after you got your iMac back?

Thanks in advance
Al
 

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I got the display replaced in three or four days, pretty quick at least.

May I ask, do you often run Windows using Boot Camp?
 
Thanks, I've been reading here and other forums that 2-4 days seems to be the average time. I'm bringing it into Apple on Wed.

No, I do not run Bootcamp/Windows. I still consider myself an Apple novice, newbie..whatever the new term is these days (lol) . I haven't had much time to look into how BootCamp works. I have 2 PCs right next to the Mac..so I just run those when needed.
 
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