iPad Mini Retina has image retention issues
Instapaper creator Marco Arment developed a simple grid test in order to detect image retention issues of Retina MacBook Pros, as such a problem was rather frequent in first-generation 15-inch MacBook Pro laptops featuring Retina displays. Now some new Retina iPad Minis suffer from the same problem but fortunately their number seems to be limited to units that use Sharp's IGZO panel.
Two weeks ago a rumor suggested that the new iPad Mini featuring Retina display faces production delays due to Sharp's IGZO panels problems, namely image retention issues. This led to significantly lower stocks ready for delivery on launch, so Apple decided to go with a quiet introduction of the second-generation iPad Mini.
For now it is unclear how many of Apple's new tablets are being affected by the issue but a few Twitter users already reported their Minis are plagued by image retention problems. While previous rumors mentioned the Sharp IGZO display to be the culprit, it is possible for displays coming from other manufacturers to be defective as well.
The image retention test mentioned in this article is available here and can be used with any tablet, smartphone or LCD/LED monitor. At this time, Apple still has to confirm the problem.