IPhone 7 lock that prevents individuals from attempting to replace the home button on their own. Users are now required to go to an Apple Store to have repairs done, with "recalibration" of the button being necessary. This is a step further than Apple went with iPhone 5S, 6 and 6S, where only Touch ID functionality would get disabled but the "return-to-home" functionality still worked. Some iPhone 7 devices with the model numbers A1660, A1779 and A1780 suffer from a problem where they show a "No service" message even when cellular reception is available. Apple will repair those devices for free within
IPhone 3G such as AirPlay and Safari Text Search. This is the last iOS release to support this iPhone model; iOS 4.3 and later are not compatible with this iPhone model due to hardware limitations and performance issues. The iPhone 3G's back featured a redesigned polycarbonate plastic housing, replacing the aluminum back of the first generation. Buttons were changed from plastic to metal, and the edges of the phone were tapered, providing a better grip. The iPhone 3G introduced the first official color options for the outer casing, with the 16GB version available in black and white. The dimensions of the iPhone