Yellow tinge from bottom to top of the screen, 27" iMac

Sorry, I messed it up 🙂 This was my intended message:

Someone has posted an interesting theory based on the patent document posted by Jacques.

http://forums.macrumors.com/showthread.php?t=872918

If this theory is correct, then it is a design flaw in the panel. It would also explain why so many screens (if not all) seem to be affected.

I'm on my sixth iMac (crazy) several were 21.5" iMac's and the last couple were 27" iMac's (I paid to upgrade to a Quad Core machine). Anyways my 2 previous iMac's a 21.5 and 27 inch model had real bad yellowish tint on the bottom half of the screen. On the grey bar test the bottom bars looked much lighter and softer. My latest 27" iMac looks great in fact the grey bars look a touch darker on the bottom of the screen. I'm not happy this was such an ordeal however I'm happy with my final machine.

I should add both 27" iMac's were 2010, week 9 machines. They were separated by 500 machines.

Message was edited by: Cbird2009

Hello everyone,

I just wanted to say that today I went to a Premium Apple reseller here in Barcelona-Spain. I checked one of the 27 iMacs on display and it had a very obvious yellow tint all over the bottom, I could see it straight away maximizing the browser window with the Apple web site on. It was like a perfect gradient from cool-blueish tone on top to a warm dirty yellow in the bottom. I didn't need to use the grey bar test.

I talked to the person in charge(they have an Apple personnel there and all, it's like a tiny Apple store inside this big electronics store) and asked him about the yellow issue. He confirmed there was a problem but said it has been fixed already. I said that one of the iMacs on display had the yellow tint and he was trying to deny it at first saying "if you could see it"... but it was so obvious that in the end he agreed. Unfortunately I couldn't check the other 3 iMacs they have on display because there were some kids playing with them, but for me the first hit was enough to be convinced about the problem.

However, I checked the serial number and it appears to be a week 2, the guy told me it's been there for a while and I thought that was understandable but after reading many posts in here about new iMacs with the problem I'm seriously thinking about not buying this computer.

It's so frustrating!. I've been waiting since mid November to get one of them but I don't want to take the risk to get a bad unit. I still can hold a bit more with my old PC but I will need a new computer sooner or later.

My last day of this long waiting ordeal will be next Tuesday(16th) to see if they come up with a new revision of Mac Pros. Otherwise I won't buy anything now.

Hello,

I've been reading these posts for the last month but this is my first time to join in. I have a week 47 27" i5 that that has a very slight bit of yellow cast in both the lower left and lower right corners. I happened to be in Best Buy today and checked out a 27" dual-core model they had that was a week 9 build. It had the very same slight yellowing in the lower corners. No yellow elsewhere (same as mine) just the corners.

I definitely agree with those of you who say they have not fixed anything yet.

Message was edited by: vonderbees

By the way! I forgot to mention:

Not sure if it has to do with a bad connection or what but the browser(safari) was incredibly slow. Not only connecting but the application itself was too slow when moving the window, resizing it, etc.

Is that normal?

I wouldn't be surprised because I have Safari for PC and it is in fact very slow.

What week was it produced? I'm of #4 myself and looking for #5

Barry, at this point the Weeks no longer matter,. Especially when we are seeing the latest Weeks having even a more severe problem. Until we see a Perfect Screen, we can forget the Weeks. And for some reason the 2 people reporting perfect screens did not post any pictures. Go Figure! 🙂

Today, I got my third iMac 27" i5.

Here is a first picture (unfortunately bad quality :/):
http://dl.dropbox.com/u/416472/IMG_0948.JPG
At the grey booting screen, I thought it's looking good, but...
I can see a yellow tinge on the right side of the display. Furthermore a grey band where the dock is.

Tomorrow I test the iMac with Dinos test series. I'm so unhappy with this situation and I don't no what I can do...replace again? Money back? 😟 😟

Greetings from germany!
Marcel

But does it show when full screen in Safari? Do you see Yellor or a Color Variance? If not, why not keep it.

mr_twin: I see the gray bar (that's a new one!) but I can barely tell the yellow hint is there. If not for the gray bar I would say keep it, but as it stands if it were mine, that machine would be going back. 😟

If it makes you feel better, I had four bad 27" models and have sworn off them for a while. I'm moving in a couple of weeks and have decided to wait until I'm settled in before buying one of these again. Maybe then they will have this issue resolved, but I stopped holding my breath a while ago.

Hope all my friends in the thread are doing well! 🙂

Mike

My latest 27" i5 iMac has the gray bar on the bottom of the screen. Honestly it doesn't bother me much and I forgot about it until you mentioned it. The yellow tinge my last iMac had was a lot more distracting. This might be my eyes playing treats on me but I swear the gray band is getting fainter over time.

"+[0012] Another challenge with utilizing LEDs in large arrays is maintaining uniformity of color in the large numbers of LEDs. ...+
+[0013] The color and output of each LED also depend fairly sensitively on temperature. The difficulties in providing proper thermal management capability can readily lead to temperature variations across a distributed array of LED light sources. Since the color qualities of LED light sources are sensitively dependent upon their operating temperatures, such non-uniformities lead to unacceptable variations in color from one portion of the display to another.+"


I think finally after months of speculation, the link Lexvo has posted gives us clear answer to this problem. Now we all could keep replacing the displays or exchanging our iMac, but the fact of the matter is that this problem will not be solved until Apple redesigns the whole display.
I have this yellow tinge too, but I have not not even bothered to call Apple. I prefer to wait until they come up with the "ultimate" solution and then I give them a call.

I'm happy to report that my new week 08 27 inch model (dual core) is 98.5% perfect with respect to the color variation problem so many people have had. There is a very slight, and I mean VERY little evidence of an issue when viewing the gray bar test - and it's well within my personal tolerance level. Full screen white background in an app such as Safari shows no problem at all. Both the demo units at the Apple store in Altamonte Springs, FL (week 42 and 43) had the yellow tinge, one worse than the other.... so it was with some hesitation that I went ahead and took the chance on this new week 08 model. It's definitely a keeper - as long as no unexpected problems appear.

I'm also using it to drive my 30 inch display simultaneously at 2560x1600 via the $99.00 display port to dual-link DVI adapter - works very well - nice to have plenty of screen real estate.

Off topic
2 Sales on CraigsList where I Live.
27" I7 iMac $2800.
21" iMac $800.
It seems people are trying to unload their iLemons.
I was tempted to email the Sellers & ask them if their iMacs past the Grey Bar Test? 🙂 L.O.L.

Guys, I agree! I've been saying this since the end of January. There is not going to be a fix for this iMac. It will be fixed in the next revision of the iMac. Forget about Week Numbers. There is no perfect iMac Week Number being made. All of them have a Color Variance problem & the only way you will be satisfied (maybe) is if you get one that shows no Variance when using normal Apps on your iMac.

Good Luck!