iPod Nano 7 won't recognize any cable, charger, or computer

My iPod Nano 7th Gen apparently no longer recognizes its USB port at all. It will not charge, sync, or even recognize that a cable is plugged in at all. I have tried multiple cables, multiple wall chargers, multiple computers, even both Mac and PC. The iPod itself functions, but I cannot restore, sync, or charge, because the iPod is apparently completely unaware anything is plugged into the USB port.

The only reaction I have ever gotten from it was if I turn it completely off and then plug it in, it will turn on. But that's it.

It was already on a very low charge when this started happening. In trying to fix it, the battery is now dead, so the iPod is basically a brick.

Just a few things:

I have already tried resetting the settings in the Settings app, and resetting by holding down the power and home buttons. That didn't work.

If any of you know anything about a problem like this short of telling me to take it in to be repaired, I would appreciate it. I don't want to have to pay for repairs (the warrantee just barely expired, of course) unless I absolutely have to.