dead battery / corroded connection = ipod dies on unplug try opening it up using ifixit's guides. you should check for corrosion on the battery cords. use a toothbrush with rubbing alcohol to clean it off. once thats done, test it. if that didnt fix it, try using a multimeter on the connection. if its lower than the amp-age than the battery advertised, get a new battery. warning: replacing the battery requires soldering, I suggest trying it tho, because this battery is easier to fix than the 2nd gen's.
