Example: The iPhone “iPhone” could not be restored. An unknown error occurred (1).
This error code based on issue related and every error code has exceptional issue and solution.
So what to do on this session while getting error?
Related error code charts and solution:
Error code Symptoms chart A: 1, 3, 10, 11, 12, 13, 14, 16, 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 1000, 1002, 1004, 1011, 1012, 1014, 1667, or 1669.
Reason: Numbered error code for check hardware issues.
Solution: Try to restore your iOS device two more times while connected with a cable, computer, and network you know are good. Also, confirm 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 or try to found out device internal hardware problem if you are technician. Remember you own at risk.
Error code Symptoms chart B: 2, 4, 6, 9, 1000, 1611, 9006, 9807, or 9844. Sometimes as a result of this issue, a device might stop responding during the restore process.
Reason: Unlatched configure of your security software or required permission denied by firewall.
Solution: Check your security software and settings, which can block ports and prevent connection to Apple servers during update and restore.
Error code symptoms chart C: 13, 14, 1600, 1601, 1602, 1603, 1604, 1611, 1643-1650, 2000, 2001, 2002, 2005, 2006, 2009, 4000, 4005, 4013, 4014, 4016. Sometimes as a result of this issue, a device might stop responding during the restore process.
Reason: Check USB connections.
Solution: If there’s an issue with the USB port, cable, dock, or hub, or if the device becomes disconnected during restore, try troubleshooting the USB connection, then troubleshooting your security software.
To narrow down the issue, you can also change up your hardware:
- Use another USB cable.
- Plug your cable into a different USB port on your computer.
- Try a different dock connector (or no dock).
- Add (or remove) a USB hub between your device and computer.
- Connect your computer directly to your Internet source, with no routers, hubs, or switches.
If you checked your connections and are still seeing the error message, check for hardware issues.
Error code symptoms chart D: 17, 1004, 1013, 1638, 3014, 3194, 3000, 3002, 3004, 3013, 3014, 3015, 3194, or 3200. These alerts refer to gs.apple.com, say “There was a problem downloading the software,” or say the “device isn’t eligible for the requested build.”
Reason: communication issues.
Solution: Check the hosts file or TCP/IP filtering, which might cause communication issues between iTunes, ports, and servers.