Can't update iPhone with iTunes

I was about to tell you that the download was probably corrupt, then I read about the charging not supported issue...

Get an old toothbrush and clean out the dock connector. That should take care of the charging not supported issue. Probably some conductive grit in there.

If the update still won't work, delete the file and re-download it.

3rd party security software or router security settings can also generate that error code. Any firewalls turned on? If so, turn them off. Navigate here and delete any and all .ipsw files you find. You will have to turn on show all hidden files & folders to see them. There should only be one, but delete all that are shown:

~/Library/iTunes/iPhone Software Updates

Re-boot your computer when finished, try again.

Try this next: Create a new user account with admin. privileges, try updating your phone using that account. Before connecting your phone, disable auto-sync under iTunes>Preferences>Devices. You can update software on any computer/account. Updating software does not touch any user data or settings. What you don't want to do is sync. If the update completes successfully, eject your phone when finished.

Here's what is mentioned for your error in the updated version (June 22nd) of iTunes: Specific update-and-restore error messages and advanced troubleshooting

Don't forget to update iTunes, the newest version is 10.3.1 Maybe a different USB cable is also worth a try.

This device is not eligible for the requested build: Also sometimes displayed as an error 3194. If you receive this error, update to the latest version of iTunes. If you do have the latest version of iTunes, this can occur when you attempt to restore using an older .ipsw file. Try restoring in a new user to ensure that iTunes downloads a new IPSW. 3rd party security software or router security settings can also cause this issue, to resolve please follow Troubleshooting security software issues. Downgrading to a previous version of iOS is not supported. If you have installed software to perform unauthorized modifications to your iOS device, that software may have redirected connections to the update server (gs.apple.com) within the Hosts file. For steps to edit the Hosts file and allow iTunes to communicate with the update server, see iTunes: Troubleshooting iTunes Store on your computer, iPhone, iPad, or iPod; follow steps under the heading Blocked by configuration (Mac OS X / Windows) > Rebuild network information > The hosts file may also be blocking the iTunes Store.

Message was edited by: Ingo2711

You're welcome, glad I could help 🙂

I don't know why this happened, but I noticed, that this error is somehow coming up in combination with 3GS devices more often, than with the new iphone 4.