2. Enter DFU recovery mode for recovery.

3. Open the correct port and allow access to the Apple server.

4, USB fault diagnosis

Connect iPhone, iPad or iPod touch to another USB port on a Mac or Windows PC. Compared with hub, the built-in USB 2.0 port of computer is the first choice. If you try to connect the device to the USB port on the front of the computer, try to connect the device to the USB port on the back. When you are finished, try to restore the device in iTunes.

If the problem persists, please do the following:

(1) Remove the keyboard, mouse and all USB devices except iPhone, iPad or iPod.

(2) Remove all USB hubs and connect your iOS device directly to the computer. If your monitor has a USB connection, please disconnect it from all USB devices.

(3) Bypass the base and connect the device directly to the attached USB cable.

(4) Restart the computer.

(5) Try to restore the device in iTunes again.

If possible, use another known-good USB cable for the test.

5. Restore on other computers.

If the above steps do not solve the problem, please try to restore it on another computer. Please make sure that the computer you are using has a USB 2.0 port, the latest version of iTunes is installed, and you connect the device directly to the computer.

6. You can usually correct this error according to the instructions in "iTunes(Windows Edition): Troubleshooting Security Software Problems"!