IPod

Hi, my son got a new iPod Nano 8GB at Christmas, and it just seems to have stopped working. Screen blank, even when charging it (which we've tried from both PC and wall socket) Through iTunes, I restored it back to Factory Settings, but that hasn't worked. I've tried the reset (holding down the Menu and Centre butons for 7 seconds +, but again no good. Whatever I try, the iPod buzzes at me, like a small alarm is going off!
Help!