"iTunes could not sync data to the iPhone because the iPhone disconnected"

[UncleRichard]

Could use Time Machine

i had this problem with a new iphone 4. i tried everything that people on multiple forums recommended and nothing worked.

if you have a new iphone and your contacts and not coming from an old model i think i have found the problem. it appears that the contacts file is corrupted because one contact has a problem. all of your contacts are grouped together in one "file" so if one contact is corrupted, the entire file will be too and will not sync.

to fix it (this is very manual) you should:
1. create a new group
2. move contacts to that group in batches (try 10 or alphabeitical)
3. sync the new contacts group ONLY
4. if that works, add 10 more contacts
5. repeat this until the error message appears; you will know which batch has a corrupted contact
6. find the corrupted contact within that batch by trial and error and delete it from the contacts list and the new group
7. add the remainder of the contacts in batches until the full group syncs
8. after this is completed you can delete the group, re-create the deleted contact(s) in the main contact list and all contacts should sync normally.

i did this and it worked. good luck

If you haven't added or deleted any contacts recently, or you are not too worried about possibly losing some you have added and having to delete some you already have, before you follow these steps you could restore your address book from Time Machine, going as far back as you are comfortable with.

 

[Awarenessing]

A faster solution to finding a corrupted contact that leads to iPhone disconnection

i had this problem with a new iphone 4. i tried everything that people on multiple forums recommended and nothing worked.

if you have a new iphone and your contacts and not coming from an old model i think i have found the problem. it appears that the contacts file is corrupted because one contact has a problem. all of your contacts are grouped together in one "file" so if one contact is corrupted, the entire file will be too and will not sync.

to fix it (this is very manual) you should:
1. create a new group
2. move contacts to that group in batches (try 10 or alphabeitical)
3. sync the new contacts group ONLY
4. if that works, add 10 more contacts
5. repeat this until the error message appears; you will know which batch has a corrupted contact
6. find the corrupted contact within that batch by trial and error and delete it from the contacts list and the new group
7. add the remainder of the contacts in batches until the full group syncs
8. after this is completed you can delete the group, re-create the deleted contact(s) in the main contact list and all contacts should sync normally.

i did this and it worked. good luck

Thanx for this great insight Timmya. What I did to find the corrupted contact which was a bit quicker but relied on my memory was:

1. Create a new group, say: "almost everything"
2. Go through your contacts and add everything to this new group bar contacts that you think you might have modified or imported since the sync problem began. Make sure you keep a note of the names of all the contacts you exclude as you'll be including them later one by one.
3. Sync the phone with only this group ticked in iTunes (i.e. uncheck the "all contacts" option)
4. Add the contacts left out of "almost everything" one by one, syncing each time to see if the problem occurs.
5. As soon as the problem occurs again then you know the trouble was with the last contact you added to the group and you can go and delete that.

In my case it was a contact I'd received via email as a vcf file that seemed to have been corrupted.

Once again Timmya thanx for the original idea of one corrupted contact subverting the whole process. You'd think by 2011 the computer would tell you that rather than some irrelevant message about "disconnection". But oh well, it's only the brilliance of these systems that has me expecting perfection from them

Good luck.

 

[slickmick]

Solution!!!

sync your osx address book with your gmail contacts and problem is solved!

first sync your contacts from your original data (phone) with gmail contacts.
then export these into address book application
then sync the new data (keep new in address book when asks and delete duplicates and other unwanted info) with itunes

This worked for me when all other methods failed to!

Good luck!

 

[Sylar]

I found that 3rd party sync cables were the culprit for me. As soon as I used the OEM cable that came with the iPhone, everything was fine.