iPod Touch (1st Gen) charging issue

I have a 2+ year old iPod Touch 1st Generation and recently within the last week it's had a charging/connection issue. It doesn't matter if I connect the cord to the wall charger adapter or to the Macbook. Sometimes it makes the ching noise that it's connected sometimes it doesn't. Anyone know how to tell if it's the iPod connector or the cord? Or is there another issue? Should I go into the Apple store and see if they can help? Any assistance would be greatly appreciated.

All - I talked to a "genius" at the Apple store today. The cord that I have is the new plugs they use for iPods. The older plugs have a wider white part (size is equal to the width of a key on a normal keyboard) that connects to the iPod. The older ones make a stronger connection and have to be unplugged from the iPod by squeezing the outside ends.