I also have a Inspiron N7010 with the same problem, laptop works on battery power, but chager light go's out when pluged in. I have replaced the motherboard and power port, then pluged in adapter and it worked till I noticed I had not removed the bluetooth card from the old motherboard. So I pulled it apart and put the bluetooth card on the new motherboard and plug it in again and it did the same thing again, the green light on the charger went off. Is it possable that a bad blue tooth card caused the problem
More aboutdell inspiron laptop adapter light turns
i think that means the adapter has or is being shorted.