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My iPhone 8 fails to update to iOS 14

While connected to iTunes on my PC the Software downloads, extracts, backs up then issues msg:

The iPhone "Tom's iPhone" could not be updated. An unknown error occurred (4000).


Seems odd that an Apple product would throw an 'unknown error'.

iPhone 8, iOS 13

Posted on Sep 28, 2020 6:33 AM

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Question marked as Top-ranking reply

Posted on Sep 28, 2020 6:36 AM

If you're getting that error while updating your device via iTunes on a computer, try this workaround:

  • Disconnect your device from the computer
  • Temporarily disable the passcode on your iPhone
  • Restart the iPhone
  • Restart iTunes
  • Reconnect the iPhone to your computer and restart the update procedure.

When finished, re-enable your passcode on your iPhone.

Regards

Giulio

5 replies
Question marked as Top-ranking reply

Sep 28, 2020 6:36 AM in response to TomD1234

If you're getting that error while updating your device via iTunes on a computer, try this workaround:

  • Disconnect your device from the computer
  • Temporarily disable the passcode on your iPhone
  • Restart the iPhone
  • Restart iTunes
  • Reconnect the iPhone to your computer and restart the update procedure.

When finished, re-enable your passcode on your iPhone.

Regards

Giulio

Sep 28, 2020 7:14 AM in response to ProustGiulio

Well I didn't disable the Password. I did make sure the device stayed awake.

I then received the following msgs:

Preparing iPhone for software update.

Verifying update with Apple.

Verifying updated software.

Waiting on iPhone

Updating iPhone software


Update successful!


My guess would be a step was missed in the update routine(s) to prompt for password if the device went back into 'standby' mode and my keeping it awake till the update started processing negated the need for the password.

Sep 28, 2020 8:17 AM in response to TomD1234

That happened to me too, updating my device to iOS 14 and to 14.0.1 (1st time in 12 years that I use iTunes to update my iPhones, and I never needed to disable my passcode before, the procedure was automatically asking for it). Your guess is my guess.

But... glad that my workaround worked for you too. Let's see what happens next time.

Take care.

Giulio

My iPhone 8 fails to update to iOS 14

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