iTunes could not backup iPhone because the iPhone disconnected

Change the name of your iPhone within iTunes then try.

One thing that helped me solves this problems was turning off a significant number of background apps refreshes.

It seems that background app refreshes were "canceling" or corrupting backup sessions. I turned them all off and have selectively turned on certain background apps. This is similar to the "Airplane" mode which I believe accomplishes something similar but I have sustained success with the background app purging as opposed to the airplane mode.

I was having the same problem. I tried almost every single option but without a luck.

For me using the proprietary apple usb cable worked. I was using the third party cable which was charging and syncing my iPhone well enough but somehow back up process kept on failing with iPhone disconnection message.

Using apple usb cable worked for me.

Cheers!

Aks203

I tired many of the above to include OE cable. Nothing worked until I checked to unencrypt the backup.

Deleting the folder with random characters in C:\Users\<USERNAME>\AppData\Roaming\Apple Computer\MobileSync\Backup solved my problem

thanks deleting the old back up an re-syncing worked perfect thanks!

I used an Amazon purchased usb-lightening cable, I had the same problem, but resolved following Lawrence Finch's advice. I deleted all my previous backup file. Then the back success.

iPhone Disconnected Error During a Backup

If you're getting the iPhone Disconnected error while trying to backup your device, we can hopefully solve the problem easily, since we don't need to worry about keeping the old backup intact. Here is what to try:

• Remove any USB hubs in the connection between your computer and your iPhone. These can potentially cause USB errors that make the restore process fail. This is also a good time to try switching USB ports on the computer and USB cables if you have a spare.
• Reboot the computer you're doing the restore with. This will fix any potential USB connection errors.
• Turn off

  Background App Refresh

  in the Settings app → General → Background App Refresh. (If you are using iOS 8 or lower, then put the iPhone into Airplane Mode.) In our experience with customers, we've found that too much background app activity (incoming messages, etc) can cause problems that result in the “iPhone Disconnected” message. (Don't forget to turn back on Background App Refresh after the backup is done!)
• If these don't work, then we need to remove (or move) the existing backup, so that we eliminate errors caused by reading or trying to update it. To move/remove your existing backup:On a Mac your backups are in /Users/your username/Library/Application Support/MobileSync/Backup.

  (Open Finder, hold the Option key, and select “Library” from the Go menu to get to your user's Library folder.)

  In Windows, the fastest way to get to your backup folders is:
  • (Windows 7 and below) Start -> Run -> type

    %appdata%

    (with the percents) and press return.
  • (Windows 8 and Windows 10) Search -> type

    %appdata%

    (with the percents) and press return. From Application Data, navigate to Apple Computer, Inc. -> MobileSync -> Backup.
  You can match your device identifier with the backup folder name by clicking on the Serial Number field in iTunes (which will switch it to your device identifier.)Rename this folder to anything you like (like “old backup”) or delete it. Renaming the backup is sufficient to hide it from iTunes and force iTunes to make a new backup from scratch — this usually eliminates the problem.
• If removing the previous backup didn't work, let's do it again in combination with another possible fix:
  • First, remove the unsuccessful backup from step 3.
  • Remove the

    lockdown

    folder according to these instructions from Apple.

-https://deciphertools.com/blog/2014_12_09_iphone_could_not_restore_disconnected/

These are workarounds, not a fix. Apple should fix this.

That fixed my "disconnect" issue.

I'm searching a lot to solve this problem and 100% you'v helped me .. Thank msavasari ✅😍

Thanks!

Renaming the backup folder did the job for me.

Update to ios11. Solve this long unsolved problem to me.

You are a literal angel thank you so much it worked