What happens when you try to update? If you have a 4G it canony go to iOS 6.1.5. For other problems:
Try the following to rule out a software problem:
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Power off and then back on your router
.- Reset network settings: Settings>General>Reset>Reset Network Settings
- Restore from backup. See:
- Restore to factory settings/new iOS device.
If still problem return it since it appears you have a hardware problem.