What if Apple 4 can't use the synchronization assistant to brush out the mobile phone information?

Is this a new machine? Upgrade your itunes to the latest version. If it doesn't work, try changing the data cable, otherwise it won't work.

If the device is unlocked, it is recommended to upgrade to the latest version 5. 1. 1.

But! ! ! Make sure your device is not a refurbished machine or a revision machine (that is, cpu replanting).