my new Iphone 4s not recognized by itunes

I have two other iphone 4s that are 16g and they both have the latest OS and show up in itunes as a device. Using the same connector, the new 4S 64g that I just received ( bought on ebay) is not recognized by itunes. Wi fi and phone work ok, charger, etc. I've restarted the phone, updated the OS,  rebooted the computer, checked online for advise but nothing has helped. Thinking there may be something wrong with the thing which is a drag because I bought it for the extra capacity to store music from itunes.

Any suggestions?