my ipod nano 7th gen only turns on when plugged in
I have a iPod nano 7th generation 16GB and when I don't plug the ipod into a charger whether it's an outlet or my computer, the ipod won't turn on. When it's plugged into an outlet or my computer, it works perfectly fine. It syncs when plugged into my computer. Also, when I keep it plugged for a while, the same thing happens so it's not a battery problem. I also can reset it by pressing the two buttons together but only when it's plugged in. When I unplug it, right away it turns black and nothing happens. I tried resetting it while it being plugged in, but afterwards I unplugged it and the screen went black again.