To repair iTunes error 14 when restoring your iPad mini, you can try the following:
1. Check the connection. Connect other functioning Apple devices with your computer and see if the error 14 notification pops up. If it happens again, there is a probability that your cable or your computer is not designed for Apple devices. Then, use the same USB cable to connect other functioning Apple devices with other computers. If the error code 14 iTunes stops showing up, then it is possible that your computer is problematic.
2. Update iTunes and your iPad OS.
3. Troubleshoot iTunes error 14 with
iOS system recovery software. Usually, such tools can repair various iOS issues and iTunes errors without data loss.
4. If all the previous solutions don't work, then the problem may be out of our hands, especially when there are hardware malfunctions or physical damages to the device. In this case, the last and safest help we can get is the official support from Apple.