Why won't my usb cord read?

I have gotten all of my software to load. When it gets to the set up and tries to read the usb it just keeps searching. I have bought 2 brand new (off amazon-if that matters) usb cords and it still will not read. Any suggestions? I have the whole machine torn apart right now and it looks as though the usb plug in is alone. Just pondering if this has happened to anyone else?