Answer to: Why are my contacts not syncing correctly between iPhones and iMac?There is a way to transfer contacts from iPhone to Mac via iCloud. you can follow it. 1.Sign in with your iCloud account and click "Contacts" 2.From the list, select the contacts that you wish to export 3.Click the icon depicting a cog wheel, and select "Export vCard" Wait for the file to be downloaded on your Mac supposing that the method does not work, seek help for iPhone Transfer.
Answer to: How do I put my iPhone 3G in DFU Mode?I can't see the purpose of putting iOS 7 to DFU mode at the moment. However the instructions are following: 1) Power the device down 2) Start holding Power button for 3 seconds 3) Hold Home button but don't let go of the Power button, 10 seconds 4) Keep holding Home and let go of Power. About 15 seconds just to be sure That's it. You should now be in DFU mode. read more: How to put iPhone in DFU mode?