Q: iTunes could not backup iPhone because the iPhone disconnected

Thanks a lot Kelly I'll try that - also thanks to Frank but where to start with removing apps ? - I suppose I could remove a large number and reinstall next time I sync ..

It's funny reading though 22 pages of everyone's proclaimed remedies like turning off wifi and other such unrelated things.

I've been having this issue since iOS 921 and get that failed to sync message about %85 of the time I connect my phone.  My wifi has not worked for over a year and recently the bluetooth part of that chip failed as well, I guess it's time to replace this 4s.

It is always a crapshoot to get the phone to actually back up but it does always sync my music, movies and other things that I don't have set to do via iCloud.  In iTunes I have the backups set to my computer because they are more comprehensive than iCloud.

I have not found anything previously mentioned that works to fix this but a mix of restarting the phone and iTunes will eventually get the backup to be current.  Oddly it doesn't seem to be any specific sequence that finally allows it to backup.

The phone actually does sync data even though the error message says it failed because it disconnected, at least that's the case on mine.

I agree, and don't think this error has anything to do with WiFi. Or with a specific USB port. Deleting the backup (in /iTunes/Preferences/Devices) or deleting the plist file in /private/var/db/lockdown is a silly workaround and certainly not a fix.

Using iCloud to backup is not a viable solution for me as I've never been able to restore that (successful) iCloud backup. So I'm left with an unresolved issue, which Apple doesn't seem to be willing to acknowledge and fix. Employees at the Genius Bar simply tell me I should setup the phone as new, instead of restoring an old backup, which I don't want to do because I then lose my SMS messages (from before they brought SMS syncing to OSX).

I do wonder if they'll be able to fix the missing iTunes tracks:

Apple has officially acknowledged community reports of inadvertently deleted music, with users left with missing tracks in their libraries that may never be recovered, in a statement to iMore.

Yeah people try to be helpful to a fault,swearing that this or that made it work when the reality is that it was none of the above.

I agree with you on the backup and if you look at that tab in the backup section the cloud version is only partial data, which to me is useless.

Like I mentioned earlier that error message is erroneous because the phone actually does sync, what it fails doing is backing up.  This dual process is very convoluted and confusing and apple should streamline it (sync & backup).  It's always a fight tomato it back up and there's no rhyme or reason but every once in a while it will actually backup and show "today" and the time.  When it used to work I would do this almost every day if not every few in case my phone was lost or hosed.  Not to sound like the others but all I can say is I've been able to make it happen with the roulette of either of these actions: restarting phone, quitting iTunes, unplugging the phone from usb port.  It's a pita but it has been thinly way I can get a backup to update.  Sit there and do it while you're doing something else so it's less frustrating!

Greg H,

"Yeah people try to be helpful to a fault,swearing that this or that made it work when the reality is that it was none of the above."

I think you've crossed a fine line here between attacking the problem and attacking people attempting to help.  The work-arounds that "worked" for them, perhaps won't work for you.

This issue has been ongoing for months...without any word/acknowledgment from Apple, however, it was entirely predictable given the increased memory size and consumption of that memory by users of the devices.

Nobody has claimed that their issue has been completely resolved by any of these methods - permanently.  For example, the deleting of the old backup file is a work-around designed to bootstrap the back up process by iTunes from scratch.  It works - at least once - and then a few weeks later the same backup issue returns.  All the original poster of this method and other's who have used it have said is that it works to at least get you ONE good backup.  Which, is good enough to at least let you migrate to a new phone.

If you really want to pursue this, open a ticket under Apple Care directly with Apple and keep pushing on them.

BTW, this isn't the only extremely annoying bug Apple has with iTunes/iOS.  Not having a backup of your phone is a serious matter.  However, recently in an Apple Care support case I opened there's another really annoying one:

I've got a fairly expensive Bose Soundlink II BlueTooth speaker that is attached to both my MacBook Pro Retina 2013, and my iPad Mini 2.  If I connect both my MacBook Pro AND my iPad Mini to the device and someone calls my iPhone...iTunes will launch (all on its own, even if it's not loaded) and begin to play a random song from my music collection.  Very, very annoying since here you are trying to talk to the person who called you and this music has spun up in the background!!

I proved this to Apple Support over the phone.  The only work-around, as there is a major Bug here with BlueTooth/OS X and/or Continuity...is to disconnect the Bose Soundlink II from the MacBook Pro ... not ideal, but at least I can get a phone call without being annoyed by iTunes.

I started experiencing this issue after updating to IOS 9.3.2. Couldn't resolve it, and deleting the backup, would allow me to successfully backup the first time, but upon further syncing, I would hit the same problem.

The solution that worked for me was: RESTARTING MY IPHONE!

Hope this helps.

It helps, but not for long, unfortunately. The problem will come back, within a week or so, and all tips posted in this thread are merely workarounds to the inevitable: the problem will occur, and a fix is unlikely to come since Apple seems to only test things on new HW, with new SW and have no QA dept to see if their software endeavours also work on systems that have never been 'installed as new', merely upgraded from a previous version.

Turned off WiFi on my phone and it worked first time...thanks

I’m fully aware that just very few of you guys might benefit from what I found out (if at all). But I decided to write this down anyway…

I was wondering why after deleting a „corrupt“ backup from my iMac and successfully creating a fresh one after that, the next (incremental) backup would be corrupt again. (Never happens on my iPad Air 2). Maybe there are some corrupted files on my iPhone?

I checked all my Apps to figure out where there might be indications of orphan files or something similar that could matter. I found that I had a couple of orphan files in my GPS tracker (Motion X). This App (like many others of the same kind) enables users to download map files at home (over WiFi) so there is no need to download them over Edge or 3G while on the road or on the bike path.

Some of those map downloads, however, were uncompleted (e.g. just x of y tiles had been downloaded). I removed all of these files on the iPhone, deleted the most recent backup on my iMac, did a „fresh“ backup - and since then I have no problems any more. All the (incremental) backups now work nicely - over USB as well as over WiFi. The „disconnected“ alert is simply gone.

Again - I probably just found the needle in my personal haystack. But maybe at least some of you out there can take advantage of this method (or feel encouraged to check their iPhones for incomplete or corrupt data) to get rid of the annoying problem we all share for months now.

Good luck!

Regards from Germany.

1) Thanks for taking the time to write this all up

2) I had a bike tracker app, no idea if it stores files locally, but since I wasn't using it anyway I deleted it. Due to the fact that I also did some more house cleaning I can't say for certain....but your tip has fixed it at my end. So, BIG THANKS for posting your solution.

Signed,

one grateful user.

Me too. Instant fix and previously had failed 20+ times.  Thanks

found this info elsewhere.. and it worked for me.

"Only thing that worked for me was resetting the network settings on the iPhone itself. Go to Settings App. General. at the bottom is Reset. Reset Network Settings. Sync again and it should work."

Thanks! I had forgotten that I had Motion X installed - I deleted it, restarted the phone and when I tried again, the back up ran as it should - great detective work!

Well, this problem has returned for me.

I fixed it last time by removing apps, now it has returned.

Even with the latest OS, iTunes, and iOS version...still having this problem.

Not fixed yet...really?