Connect your iphone to the computer and open itunes.
say you put in dfu mode, no?
because when in dfu mode in itunes have a tab that says restore the iphone, the prick and wait.
PD. DFU Mode
1 connect the iphone to the computer with itunes open.
2nd off iphone
3rd keep the two buttons pressed for 10 seconds
4th after exactly 10 seconds, release the button above and still pressing home button
Appear a sign on itunes saying it found an iPhone in recovery mode.