My i-pod classic (7th generation 160gb) only works when connected to my car charger. Works great actually. I can listen to my music and everything (as long as it's connected to car charger). As soon as I disconnect it from car charger it goes dead. When connected to home charger the battery icon does not show it's charging then it goes to a screen that says "Connect to Power" with a battery symbol and a yellow triangle with an exclaimation point in it....can you tell me what's wrong? I've already replaced the battery. Thank you.