iPad 1st generation USB Issue
You could try to set it in DFU Mode, sometimes that resolves the issue with a faulty USB-I/O. 


  Entering DFU Mode on iPhone, iPad or iPod touch:
  
  
  Plug your device into your computer with a USB cable. 
  Turn off the device.
  Hold the Power button for 3 seconds.
  Hold the Home and Power buttons for 10 seconds.
  Release the Power button but keep holding the Home button.
  After about 15 seconds you will be alerted by iTunes saying that it has detected a device in Recovery Mode.
  
  
    Source: https://www.theiphonewiki.com/wiki/DFU_Mode
  
  


Maybe it depends on what iOS you are, so if it does not go into DFU Mode, research it.

Good Luck!