ITunes sometimes encounters difficulties in recognizing an iOS device. This is the case, for example, when you connect your iPhone to a computer to update, synchronize or backup content without going through iCloud. Checking the Physical Connection In the event of a connection problem with iTunes, it is important to ensure that the current cable is working properly. To do this, if you have another cable available, try it on your iPhone, and in case nothing changes, it is best to switch to checking the USB connection of the PC. The process may differ between a PC and a Mac, but the key is to find the user profile of the computer that lists all active connections from the USB ports of the machine. On a Mac, this list is visible from System Information via the Apple Menu by holding down the Option key. You can then navigate to the USB section under Hardware and you will have all the information about what is currently recognized on your USB ports including your iPhone. On a Windows PC, open the Device Manager to verify your USB connection. Caution, this also requires the Apple Mobile Device USB Driver installed on the machine and listed in the list of USB Bus Controllers. If everything is in order and you can see your iPhone in the list then it is very likely that it is a software problem. Solve the software problem The first step is to reboot and reset iTunes. This will prevent the program potentially responsible for blocking from harming the connection with iTunes. Restoring the phone only as a last resort via the settings of the iPhone itself: General> Reset> Clear content and settings. Better to reinstall iTunes on the computer since this would raise all the inconsistencies of the software and replace all the failing or missing files of the system. This is even a good idea as you will reinstall the latest version of iTunes on your computer. If none of these solutions work, it is recommended that you ask Apple for support by phone or in an Apple Store.