Uninstall and reinstall the latest version of iTunes (see instructions for Mac and Windows). If that doesn't resolve the issue, see the steps for 1602.
Try the following steps to resolve this error:
If you receive this error and the iOS device is not automatically placed into recovery mode, it may be necessary to do so manually. Refer to iPhone and iPod touch: Unable to restore for steps on placing iPhone into forced recovery mode. Also, remove the IPSW and attempt to restore again. If you do not want to remove the IPSW in the original user, try restoring in a new administrator user.
This error is often related to USB timing. Try changing USB ports, uninstalling and reinstalling USB ports, and other available USB troubleshooting steps (troubleshooting USB connections, device not recognized properly, computer won't recognize a FireWire or USB device). If you are using a dock, bypass it and connect directly to the white Apple USB dock connector cable. If the issue persists on a known-good computer, the device may need service.
If the issue is not resolved by USB isolation troubleshooting, and another computer is not available, try these steps to resolve the issue:
If the steps above do not resolve the issue, try restoring using a known-good USB cable, computer, and network connection.
This error may indicate a hardware issue with your device. Follow the steps in this article. Also attempt to restore while connected with a known-good 30-pin Dock Connector cable, computer, and network to isolate this issue to the device. The MAC address being missing or the IMEI being the default value (00 499901 064000 0) can also confirm a hardware issue. Out-of-date or incorrectly configured proxy or security software, such as FoxyProxy, can cause error 1611. To troubleshoot third-party security software, follow these steps.
Insert SIM card into device and try again.
See resolution steps for error code 1004.
siehe auch: http://support.apple.com/kb/TS3694