DELL Laptop doesn’t charge

Hi, I’ve got a problem with my Dell Inspiron 640m. It just went dead the other day, and stopped charging. Doesn’t seem like there’s much I can do. The adapter light is green, but as soon as I plug it into the computer the green light fades away.
I tried another, brand new adapter, and the same thing happens. I figure my laptop is ready for the computer graveyard, would appreciate any thoughts though. Thanks.