Ashraf try this first. Try DFU Mode to restore Iphone.
To enter DFU Mode:
- Quit iTunes;
- Connect your phone to the computer;
- Turn off your phone;
- Hold Power and Home buttons for exactly 10 seconds;
- Release the Power button but continue to hold Home until the computer displays a new USB-device. That may not happen - in this case, hold the Home for 20-30 seconds;
- The phone's screen will not be included in DFU Mode, do not wait;
- Open iTunes and follow the above instructions for flashing. Screen phone may appear white - this is normal.
http://modmyi.com/forums/general-iphone-... and http://forums.macrumors.com/showthread.p... give you some information
If this does not work for you then you may just have a a bad dock connector on the iPhone. In general I believe that error 28 is considered a hardware error.
You Must replace it. Good luck to you.