Check for hardware issues
Errors: 1, 3, 11, 12, 13, 14, 16, 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 53, 1002, 1004, 1011, 1012, 1014, 1667, or 1669.
Your device or computer might have a hardware issue that stops the update or restore from completing.
- Check that your security software and settings aren't blocking your device from communicating with the Apple update server.
- Then try to restore your iOS device two more times while connected with a cable, computer, and network you know are good.
- Make sure that your security software and settings are allowing communication between your device and update servers.
- If you still see the error message when you update or restore, contact Apple support.
If you still see the error message, check for outdated or modified software.