More about this phenomenon from iPhoneAtlas. I read from MacRumors that most of the 7R7 and 7S7 batch iPhones suffer from this problem. 1.1.1 update really dint’ help iPhones from this issue unlike iPod Touch. For now, the best way to test your iPhones for dead pixels or negative black screen issue is by visiting this wonderful site (http://appleservedup.com/).Here is the famous Jay Z album cover test snapshot. Visit the site to test your iPhone screens and return them if you find them faulty – You deserve the best iPhone …