オリジナル投稿者： JOSE PEDRO ,
Perhaps it happens because enters in DFU mode directly. Or perhaps you have jailbreaked your iphone. Do this steps: 1.- Do a backup of your personal data and software if it can be done. 2.- Turn of the phone 3.- Plug the usb apple cable to your computer. 3.- Keep pressed the () central button and plug the usb cable to the iphone. It should enter in DFU MODE showing the itunes logo and the USB PLUG with an arrow. Start Itunes and perform an iOS UPDATE. Good Luck!