It seems that many iPhone Users have been facing issues after a Siri Installation through Cydia.
Whatever the reason is, you don’t need to Restore your Device, but just modify some stuff in the Filesystem.
Here is what to do, step by step:
1. Connect your iPhone with USB to a Computer.
2. Download iFunBox or iPhoneExplorer.
3. Browse at this Directory: /System/Library/LaunchDaemons.
4. Delete the File com.apple.Springboard.plist and change the Extension of the file com.apple.Springboard.bak to plist.
5. Hold the Power Button and the Home Button until the Screen goes Black.
6. Hold the Power Button to Power On the Device and see your Wallpaper smiling at you! 😉
If the problem isn’t fixed, try to delete the two files installed by your Siri Installer at /Library/MobileSubstrate/DynamicLibraries.
If it still isn’t fixed, just Restore your iPhone and you should be fine….