iMac Yellow Tint

[hashmukh]

Imac Yellow

IM ON MY 2nd IMAC NOW IN 2 WEEKS!!.. both have had yellow issues,, i just got mine now, and im sending this one back aswell now! very very angry with apple!

 

[jgo78]

IM ON MY 2nd IMAC NOW IN 2 WEEKS!!.. both have had yellow issues,, i just got mine now, and im sending this one back aswell now! very very angry with apple!

this is dissapointing to hear. Ask them for a discount or freebee with this third one for all your trouble.

 

[teerexx52]

IM ON MY 2nd IMAC NOW IN 2 WEEKS!!.. both have had yellow issues,, i just got mine now, and im sending this one back aswell now! very very angry with apple!

I got mine a week ago after the same problems with the very first 27" models. Mine was cool on the left half of the screen and warm (yellow) on the right half. Not going to accept an exchange. Can't see it will be any different. Going to ask for a refund.

 

[IndustrialSpace]

I've been following this issue for a while. All of the iMacs will have some yellow tint. Some worse than others. Most just end up settling after several exchanges. It isnt possible to have a perfect screen due to the design of the monitor. If you look at the patent for the iMac, it explains that the screen design causes a lack of color consistency.

 

[RadiDoc]

IM ON MY 2nd IMAC NOW IN 2 WEEKS!!.. both have had yellow issues,, i just got mine now, and im sending this one back aswell now! very very angry with apple!

I just sent mine back... 2nd imac also. I didn't bother to get another replacement. I'm so disappointed. I've been a PC user all my life and this is my second attempt to change from PC to Apple. I'm spending a lot of money to buy the imac and it's like lottery, a perfect one or yellow tint/dead pixels.

 

[Michaelgtrusa]

Very sad to hear this.

 

[kfscoll]

If you look at the patent for the iMac, it explains that the screen design causes a lack of color consistency.

Do you have a link?

My '09 27" iMac has a bit of screen yellowing but honestly I don't even notice it any more...which is good because it's a "defect" I'm expecting (and willing to accept, depending on severity) in my new '11 iMac...if it ever ships.

Honestly, I think the color non-uniformity is just a limitation of the AIO design. It is what it is.

 

[Keerock]

Yellow tint with my new 27" iMac

Had the Yellow Tint issue, returned it at the Apple Store where I bought, no problems... but now I have 2 new issues. Noisy Super Drive on Start/Wake and very slow network/internet connections after waking from sleep... oh boy. :-(

 

[IndustrialSpace]

Do you have a link?

My '09 27" iMac has a bit of screen yellowing but honestly I don't even notice it any more...which is good because it's a "defect" I'm expecting (and willing to accept, depending on severity) in my new '11 iMac...if it ever ships.

Honestly, I think the color non-uniformity is just a limitation of the AIO design. It is what it is.

Here's a link to the patent from another poster.

About a month ago, I posted a thread speculating the cause of the yellow tinge problem and color/tint variability on the new iMac 21" and 27" models.

Since then, I received my 27" iMac which had the problem, and a subsequent replacement which was much better but not perfect. After following the thread on the Apple discussion forums concerning this issue, I read this patent document posted by Jacques LaPorte for U.S. Patent #20090135583A1 (received by Apple on May 28 2009) which details "a display system with a distributed LED backlight." According to the patent description, this is a new display technology which includes a "plurality of tile LED sources." Figure 1 on page 2 shows that this panel is intended for desktop systems, i.e. the iMac. Figure 2 on the third page shows the exploded view of the display panel and complicated arrangement of various layers in the panel.

Apple itself alludes to the difficulty in using LEDs in large panels (larger than 20 inches) such as those in the iMac:

[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.​

Apple's patent design is an attempt to address these issues using an array of LED "tiles" to deal with thermal and structural concerns as well as individual LED variability. Perhaps some of the yellow screen problems are still due to thermal problems. Most interesting to me is the presence of multiple "backlight diffuser sheets" (item 212) which are between the LCD sub-assembly (208) and the reflector (214). As I posted in my previous thread, someone who wrote to Gizmodo claims that it is distortions in the backlight diffuser sheets which is causing the tint variability in the iMac panels.

I have to say that this is the most plausible reason for the problem as I noticed in my own iMac what appears to be a "curtain effect" of alternating blue and yellow tint vertical columns that looks like it could be due to a diffuser material that has bunched up or irregular underneath the LCD panel. This may be due to the manufacturing process, dislocation during shipping or the inherent design of the panel.

Which brings me to the bad news. Since this is Apple's patent and design, this is not a situation of a "few bad panels" from LG, but may be the basic nature of this display technology that would be present no matter who manufactured the part. Many on the forum have commented that the Dell 27" U2711 uses the same display. While the LCD sub-assembly itself might be shared with the Dell, they are not using Apple's patent design for the LED tile array and diffusers. Bottom line is that unless Apple were to radically redesign or switch technologies (highly unlikely until a major revision), I think that the color/tint variability issues may unfortunately be with us for the duration.

 

[Chris5488]

With my 2011 27" iMac, I can see some slight yellowing on the bottom of the screen when a grey screen (like the boot screen) is shown. But when your not staring at a grey screen, you wouldn't even notice it. If I didn't read these topics or never heard about it I would never noticed it. Most computer displays perform far worse on other points. So I'm happy .

It does get prominent when you look down on your iMac, because the viewing angle makes it yellow, and that's also the reason why I notice it slightly on the bottem of my screen: It's because it's such a big screen and you'll be looking down on the bottem of your screen, and that's why the yellow becomes visible there!


Well, that's my opinion/experience. But since there are so much other people who are complaining about it, I think it's not just a result of the viewing angle and some iMacs do have a real yellowing issue that's goes beyond the viewing angle.

(sorry for my english)