Just like Bob said you might have to disassemble your iPhone. Have you tried to do a hard reset? Press and hold both the Sleep/Wake button and the Home button for about ten seconds, until the Apple logo appears.
Also try the DFU setting and see if it is being recognized. DFU stands for Device Firmware Update. Unlike Recovery Mode, DFU Mode doesn’t load the firmware/OS currently installed before restore attempt. DFU mode is a last resort to restore if a restore using Recovery Mode doesn’t work. IT WILL ERASE EVERYTHING ON YOUR IPOD. Turn off your iPhone.
Hold down the power and home button.
When you see the Apple logo, release the power button '''but continue holding''' the home button down.
Open iTunes and wait for it to tell you that its in restore mode.
Again if none of this works you will have to at least open it to examine your connectors etc. Goo dLuck