Dell M1210 not charging

Well recently about 2 weeks ago I started having problems charging my Dell M1210 laptop. At first the battery would just stop charging but if i wiggled the cord around i could get it to charge for a little bit. Now the battery won't charge at all. I don't think the power adapter is the problem because when plugged into the wall, the green light is on the adapter. I'm not sure what the problem is. The battery is dead right now and the battery just won't charge at all. Could it be the battery itself? Or the motherboard? I really hope its not the motherboard, because my warranty is up and I really don't want to pay a lot to get the motherboard fixed. Anybody have any ideas? I bought the laptop just over a year ago for $2000, and I really don't know what to do.