Pink screen hardware bug strikes 21.5in iMacs

11 April 2016, 05:01

Word reaches us from a reliable source that some new 21.5in non-Retina iMacs have a potential manufacturing fault that causes the screen to take on a pink tint. Apple’s engineers are said to be working on a fix for the problem.

The problem only affects the Mac’s LCD panel during the first few moments of it being powered-up and disappears shortly afterwards. Our photo below shows the same affected iMac, with the bottom image showing the iMac turned on for one minute, with the image above it showing how the tint has disappeared after around 20 minutes of use. However, if the iMac is switched off and “left to cool”, the problem returns again.

Our source has seen the issue with more than ten iMacs he ordered for the business where he works. Speaking to various Apple tech support staff in a bid to resolve the issue, he learned that the problem allegedly only concerns LCD panels manufactured by LG. Apple uses several manufacturers for its screens. The fault is apparently likely to be fixed in an up-coming EFI (firmware) update although one engineer said that the backlighting LEDs are “doped“ with gallium-phosphor so that they’re slightly on the blue side of true white, and the doping of LEDs in the affected panels has been increased to maximize their working life. A side effect is that the LEDs have to physically warm up each time to show the correct color gamut.

If your iMac is affected by this issue then you can either wait for the promised firmware update or return the model for a replacement with the hope that you’ll get an iMac with a non-LG-manufactured screen. It’s possible to discover the manufacturer of the LCD panel used in a Mac, although the information returned is not always 100% reliable because of Apple’s manufacturing secrecy.

Screen tinting across all Apple products is a favorite complaint amongst users on various Apple-related support forums, although the issue is rarely reported upon in the mainstream press.




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