Can't do backup via iTunes, "Device disconnected" automatically

[gloryunited]

I was about to migrate from iPhone 5 to 5S, so I decided to do a full backup plugged in, via iTunes. I do iCloud backup everyday but iTunes backup seems to be safer and more complete (or not?).

I clicked "Backup Now" and the progress bar started to move. After a while the device appeared disconnected/ejected. (not visible on the left panel anymore)

Under Preference>Devices Backups, it is EMPTY. It doesn't use up any available space on my drive during the said "backup process".

I have tried numerous times, restarting iTunes app, restarting MBA and iPhone. Is it something to do with iTunes 11 running on 10.8.4?

(MBA 2013, OS X 10.8.4, iTunes 11.1.1;
iPhone 5, iOS 6.1.4)

Any help would be much appreciated. Thanks

 

[mlsusa]

A similar thing happened to me when I was backing up my wife's 4S to get her 5s ready. Not sure if this is the case with you but for her it was because her 4S was full. Makes me think even when doing just a backup iTunes needs to do something in the phone that requires some disk space. After deleting some apps and clearing some room -- not a lot, maybe less than a 100m -- I was able to do the backup.

 

[gloryunited]

A similar thing happened to me when I was backing up my wife's 4S to get her 5s ready. Not sure if this is the case with you but for her it was because her 4S was full. Makes me think even when doing just a backup iTunes needs to do something in the phone that requires some disk space. After deleting some apps and clearing some room -- not a lot, maybe less than a 100m -- I was able to do the backup.

Thanks, but my 32GB iPhone 5 got like 5+GB of free space... and my MBA got more than 40GB.

The thing is, iTunes doesn't prompt/alert anything. The progress bar at the top just stops.
(well the very first time this happened it did alert "Device disconnected while backup" or something similar)

 

[gloryunited]

Here is my setting on the iPhone's Summary tab.

Someone said there's some bugs with certain Sync settings. What should I check/uncheck?

Thanks in advance.