These steps are generally recommended by Apple Support to help iOS device users deal with iTunes restore or update problems as manifested by the error 9 prompted on the iPhone 6. Be sure to test your device after completing each step to see if it has fixed the problem.
- Check the cable connection from the iPhone to the computer or vice versa. Ensure there are no loose connections and all cables are properly plugged in.
- Unplug the cable that connects to your iPhone from the USB port on your computer, and then reconnect it. Do the same from your iOS device.
- Ensure the USB cable is directly connected to the port on the phone. If necessary, try to remove any third-party battery packs or cases.
- Make sure all virtualization apps like Parallels or VMWare are closed as these apps might interrupt the computer’s ability to communicate via USB, especially if they are not configured properly, or outdated.
- Reboot your computer and iPhone.
- Verify and ensure you’re using the latest version of iTunes.
- Try to disconnect other USB devices from your computer except for your keyboard and mouse, and then reconnect your iPhone.
- Try using a different USB cable to connect your iPhone to your computer.
- Try connecting to a different computer and performing the same restoration process again
If none of these work, then you may consider trying any of the following methods:
Note: Though it’s not a hundred percent guarantee that these solutions might work for you, it wouldn’t hurt if you’d give any of them a try before you consider buying a new one.
- Plug something into the iPhone’s audio jack like ear buds or anything that fits. Leave the ear bud attached to the audio jack and then try to restore or update your device.
- Use a heat gun and carefully heat the dock connector, battery connector, and other components in the circuit board. Just set the heat gun to a minimal heat temperature like 650 degrees Celsius or to any level good enough to warm things up. This workaround however is only applicable to those who’ve got skills and guts to take the risks.
- Reset the Lockdown folder on your Mac or Windows computer. This method should only be performed as directed by an Apple technician but if you’ve already tried everything to no avail, then you may consider this as your last resort. There are times when you cannot sync, back up, or restore your iDevices, and all you have to do is to reset the Lockdown folder on your computer. This workaround can help eliminate corrupted files from that folder that are causing the problem. The process of resetting the Lockdown folder in iTunes varies on the operating system of the computer you are using. You can view the steps on how to reset the iTunes Lockdown folder for OS X, Windows XP, Windows Vista, 7, 8, or 10 from the Apple support page. URL: https://support.apple.com/en-ap/HT203887
