1. tsky74's Avatar
    So, when I try to sync my iPhone 4, I get the below message:

    "iTunes could not back up the iPhone "phone name" because an unknown error occurred (-20)".

    Anyone else get this error or know what it is?

    Thanks!
    07-02-2010 03:26 PM
  2. big9erfan's Avatar
    I can't say I've ever seen that particular error

    Check to see what's set to be synced and try to eliminate the culprit.

    Start with eliminating the syncing of music and videos, then photos, then contacts and calendars.
    07-02-2010 03:48 PM
  3. tsky74's Avatar
    Thanks for the suggestion. I'll try.
    07-02-2010 05:10 PM
  4. Cleveland's Avatar
    So, when I try to sync my iPhone 4, I get the below message:

    "iTunes could not back up the iPhone "phone name" because an unknown error occurred (-20)".

    Anyone else get this error or know what it is?

    Thanks!
    Only time I ever saw this error was while using the beta versions of iOS4 before iTunes would recognize folders... maybe try reinstalling iTunes... sounds like a software glitch.. or possibly a faulty USB dock connector
    07-02-2010 06:19 PM
  5. big9erfan's Avatar
    Cleveland's suggestion makes me think to ask, are you sure you are running the latest version of iTunes ( 9.2 )?
    07-02-2010 06:26 PM
  6. tsky74's Avatar
    Yes. I have two iPhone 4 and my wifes syncs fine. I'm wondering if it's because I activated my 4 with my 3g and not as a new iphone. However, I did the same with my wifes and hers is fine. I'll play around once I get home to see if uninstalling some things will solve this.

    Thanks. I'll post if I figure it out.
    07-02-2010 07:37 PM
  7. Cleveland's Avatar
    Yes. I have two iPhone 4 and my wifes syncs fine. I'm wondering if it's because I activated my 4 with my 3g and not as a new iphone. However, I did the same with my wifes and hers is fine. I'll play around once I get home to see if uninstalling some things will solve this.

    Thanks. I'll post if I figure it out.
    I did the same from my 3GS and have had no issues whatsoever... hmmm strange...
    07-02-2010 07:47 PM
  8. tsky74's Avatar
    Well this morning, I went ahead and tried to remove and reinstall all the apps/music/contacts/etc., however this didn't solve the error. So, I tried to do a clean restore and use my back up file to reinstall all again. When it uninstalled all and went to restore the phone, it got stuck and stayed there for about 30 min without doing anything. Tired of waiting, I unplugged the phone and rebooted the phone and computer and did a complete install as a new phone (would not let me use my back up file). So I lost everything and starting fresh. I was then able to get my phone to back up without the error. I'll try again tonight to do a backup and hope it's gone for good.
    07-03-2010 05:41 PM
  9. tsky74's Avatar
    Well, this AM, tried to sync my phone with itunes and still get the same error message. I can sync, however, there is no back up. Oh well. Maybe time to pay a visit to an Apple Store.
    07-04-2010 07:27 AM
  10. ghostface147's Avatar
    My cousin went through 2 iPhones before he got one that worked. He had the exact same error.
    07-04-2010 09:02 AM
  11. tsky74's Avatar
    Did he find out what the cause was? The phone is functional, just can't make a backup.
    07-04-2010 04:14 PM
  12. connor sweeney's Avatar
    UK 3GS iTunes 9.2 iOS 4.0.

    Phone will not back up. Tried on two different pcs using Windows XP.

    Tried everything, reinstalling itunes, restore original factory settings on phone - setting up iTunes on a clean pc.

    Wish I'd stayed with the previous software version.

    And to cap it all iOS 4.0 STILL doesn't have all the features we've been screaming out for.

    Extremely frustrated.
    07-06-2010 01:48 PM
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