Q: i found error no -1 at half compliting update 8.3

Hello Sanjay,

Getting an error -1 when updating your iOS device is indicative of a hardware issue. The information outlined below can help resolve this and get your device updated.

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.

1. Check that your security software and settings aren't blocking your device from communicating with the Apple update server.
2. Then try to restore your iOS device two more times while connected with a cable, computer, and network you know are good.
3. Make sure that your security software and settings are allowing communication between your device and update servers.
4. 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If you still see the error message, check for outdated or modified software.

Get help with iOS update and restore errors
https://support.apple.com/en-us/HT204770

Sincerely,

Allen