If you one of those owners of trendy gadget that can't understand why the computer sees the iPhone, then you can find the reason by yourself without going to a specialized service. To do this, first check the connection.
If you connect via the USB cable, inspect it, drawing attention to the presence of oxidations, kinks, and other external damage. If the problem is not visualized, still try to replace the wire.
When the condition of the connection cable of the iPhone and the computer may occur because of a problem with the USB input on the computer. Check it by plugging in a USB flash drive. If it is not defined, most likely, it's the lack of drivers. You can fix the problem if you download them online and install on the computer. After that it need to reboot and try again to connect your iPhone.
To connect the iPhone via cable needed USB 2.0 and above. Otherwise, the connection will fail and you will see on the computer that this device can run faster.
If for some reason the computer doesn't see iPhone broken can be input on the phone itself. Check it out just plugging in the charger. If your iPhone is not charging, you can purge the corresponding input, if contaminated, carefully wipe with alcohol cotton stick, and when the oxidation - gently hold ordinary eraser on the contacts. If the phone suffered wet, then dry it with a Hairdryer.
If connector and cable are all OK, we can assume that the broken Flex cable of the power connector. Despite the fact that he rarely goes bad, but such damage occurs sometimes due to frequent crashes of the device.
It is worth remembering that if you are not an experienced master, then you should not spin the device or subject it to other mechanical shocks, otherwise you can lose the guarantee on the iPhone. If any item from iPhone doesn't work, replace it preferably on the original and official Apple. Because spare parts of poor quality, the computer may not see the iPhone.
Sometimes the computer gives an error, which refers to the discrepancy between SIM cards specific requirements. In such cases, no need to change it, the problem can be solved if you pull the SIM or turn on airplane mode in the settings of the iPhone.
If you connect your iPhone to your computer appear error SyncServer or MobileDeviceHelper, and the monitor you see a message that the app is closed, most likely your devices have different time zones or time. To fix the problem, you should check the relevant settings.
If you are trying to connect via wi-fi, check to see if this mode on both devices. The computer can see the network indicator. If there appear other sources of wireless technologies, it is likely that the computer problems do not exist. Available connections should also appear on the iPhone. Sometimes the problem is lack of communication between iPhone and a computer is solved by rebooting both devices.
The computer may not see the iPhone due to issues with the firmware. Especially often such happens, if the phone was unlocked. In such cases, it may help reset to factory settings and install the official firmware.