my dell laptop adaptor was shoing no green light and no output voltage. i had to opeh it with a thin knife and a little hammering with palmtop on all four side periphery. then checked input side 220 volt was there but output zero. i desoldered the output cable then adaptor was showing green light. output cable was got disconnected as welll as shorted at connector plug. soldering the connection and removing the short and connecting back to adaptor made the adaptor working again.