The most common problem reported to the Apple Support Forum is that some of the iPhone 4S displays have a yellow tint. The same issue has been reported previously, after the release of different Apple devices and already the blogosphere has found a nickname for it: ?yellowgate?.
Now some users compared their newly iPhone 4S to the previous iPhone and noticed that the screen has washed out colours, the contrast is lacking and/or the whites have a yellowish shade. The fault seems to be specific to the white models, as users didn?t report black iPhone 4S having yellowish displays.
Commenters explained the glue didn?t fully cure or harden and it caused the situation. One user experienced the same yellow shade on the touchscreen, a year ago when he purchased his iPhone 4 and, after a couple of weeks the problem disappeared. The fresh glue hypothesis does not cover all the alleged screen defects. One user expressed disappointment and described his discontent ?The colors are less vibrant, and some are pretty washed out. I?ve also noticed that the screen is more directional than the 4 screen, and in some viewing angles it?s more yellow, and in others it?s more contrasty. I?m really hoping this is a glue issue, which could improve. I don?t think I?ll be able to get used to this.?
This is not the first time when Apple has to face displays with yellow tints after the release of a new device. When iPhone 3GS hit the market, some users complained about the similar situation and the researchers found the problem is caused by the some cases blocking the light sensor. New iPhone 4 users reported last year that the display on their devices presents discoloured yellowish areas and the cause was attributed to the glue not having hardened. The same complaint came from new owners of iPad 2 and they received the same explanation. Typically Apple replaces faulted devices but an official statement on this matter was not offered at this time.