iPhone could not backup because it was disconnected.

Tom Schrier

macrumors member
Original poster
Aug 7, 2014
42
10
Norway
iPhone could not backup because it was disconnected. [SOLVED]


Symptom

  • Error message during iPhone backup using iTunes.
  • "iTunes could not backup the iPhone because the iPhone disconnected"
Environment

  • iPhone 6s Plus (iOS 10.3.3)
  • macOS Sierra 10.12.6, running iTunes 12.6.2.20
  • Windows 10, running iTunes 12.6.2.20
  • Default lightning to USB cable.

I have tried the following

  1. Turning the iPhone off, then on again.
  2. Hard reset the iPhone by holding the home button and sleep/wake button for 10 seconds.
  3. Restarting iTunes and check for updates.
  4. Turning the Mac off, then on again.
  5. Using a different Lighting to USB cable.
  6. Using a different machine (Windows 10 PC with iTunes 12.6.2.20)
  7. Using a guest account on Mac.
  8. Using a new administrator test account on Mac
  9. Using a new administrator test account on Windows 10
  10. Renaming old iPhone backup in /Library/Application Support/MobileSync/Backup/
  11. Deleting old iPhone backup in /Library/Application Support/MobileSync/Backup/
  12. Put iPhone in Airplane mode with Low Power mode enabled and trying to backup.
  13. Followed the If your iTunes backup couldn‘t be completed or you can‘t restore from a backup support article by Apple Support.
  14. Carefully clean the lighting port to free it from lint and dust.
  15. Trying to backup iPhone while Mac was in safe mode by holding the shift key during boot.
  16. Trying to create a unencrypted backup.
  17. Turning off Wi-Fi sync
  18. Clearing iTunes cache (~/Library/Caches/com.apple.itunes)
  19. Contacted Apple Support on Twitter.
August 15, 2017, update

Apple Support on Twitter had a Senior Advisor reach out by phone to continue working on this issue with me.

September 19, 2017, update

Updated iPhone to iOS 11.0 (Public release). Updating the phone to iOS 11 solved the problem for me.

Notes

  • There are no files inside the unsuccessful backup folder (Image), there should be files there (Image).
  • iPhone 7 (iOS 10.3.3) can backup to iTunes just fine.
  • iPad Pro 12.9″ (1st generation) (iOS 10.3.3) can backup to iTunes just fine.
  • I am currently not willing to restore from an iCloud backup cause of Health and Apple Watch data loss.
[doublepost=1502733075][/doublepost]I have also created a thread on the /r/applehelp subreddit here

Edit: Added August 15, update
Edit 2: Added September 19, update
 
Last edited:
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Mlrollin91

macrumors G5
Nov 20, 2008
13,528
9,078
Ventura County
This has been an issue since iOS 10.2. I've been submitting bug reports since the first beta of iOS 10.2. Nothing has been fixed.

The workaround that seems to work for me is always making sure iTunes is completely closed when plugging in the device. Then open iTunes and backup the device. It's not a 100% workaround, but it's more likely to work than fail in my 6 months of experience.
 
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Reactions: xpxp2002

Tom Schrier

macrumors member
Original poster
Aug 7, 2014
42
10
Norway
This has been an issue since iOS 10.2. I've been submitting bug reports since the first beta of iOS 10.2. Nothing has been fixed.

The workaround that seems to work for me is always making sure iTunes is completely closed when plugging in the device. Then open iTunes and backup the device. It's not a 100% workaround, but it's more likely to work than fail in my 6 months of experience.
Thank you for letting Apple know about this problem.
I've tried the workaround multiple times now, and unfortunately, it doesn't seem to work for me. My current plan is to wait for iOS 11 and a new version of iTunes next month to see if that fixes the problem.
 

FastEddiebags

macrumors 6502
Jun 1, 2012
336
1
NJ
I have also had this issue and tried everything. I'm just going to wait for the new iOS and high sierra and hope for the best.
 

xpxp2002

macrumors regular
May 3, 2016
230
385
I've had this issue since at least 10.1, or possibly even earlier. Still haven't figured out the cause. It seems to work once when you do a full backup, but every backup after that fails.
 

Cutiekitty92

macrumors 68000
Apr 11, 2015
1,760
742
UK
I have this problem too, I manage to get a backup eventually after trying a few times so it doesn't concern me as much anymore but I also have it when I am on a call and need to dock my iPhone for power it drops the call as there is no phone network
 

funxionit

macrumors newbie
Sep 5, 2017
1
0
I think the problem is a corrupt backup, so iTunes cannot add to the old backup with the new data.

To fix the problem, unplug your device from iTunes, open preferences in iTunes, click on Devices, option click on the device backup, select archive backup, and close iTunes preferences. Connect the device again to iTunes and a new full backup should be completed.

You can now delete the archived backup.
 

joeblow7777

macrumors 603
Sep 7, 2010
6,153
7,179
I've had this happen a few times while backing up to iTunes, but it always worked eventually if a kept trying.
 

xpxp2002

macrumors regular
May 3, 2016
230
385
I think the problem is a corrupt backup, so iTunes cannot add to the old backup with the new data.

To fix the problem, unplug your device from iTunes, open preferences in iTunes, click on Devices, option click on the device backup, select archive backup, and close iTunes preferences. Connect the device again to iTunes and a new full backup should be completed.

You can now delete the archived backup.
I've done this several times. It seems to work for the first (full) backup. Then every back up after that fails again.
 

BobCowe

macrumors newbie
May 20, 2018
4
0
I was also suffering from this problem. Back failed as iPad disconnected...
After having tried all the suggestions, I stumbled on this post https://discussions.apple.com/thread/8020128
which suggests deleting any apps taking up more than 3Gb.
For some reason I had Minecraft installed with 4.15Gb. Deleted it, and the problem was fixed immediately.
 

lgjay

macrumors member
Nov 12, 2019
36
17
Was having the exact same issue with my iPhone 11. A reboot fixed it. Strange.
 
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