Inspiron 1420 will not power up

I need help determining what could be wrong with my computer.  I can plug in the power cord adapter into the wall outlet and the green light on the adapter comes on as it should.  As soon as I plug it into the laptop the light goes out and will not come on until it is unplugged from the wall and plugged back in.  I have removed the battery from the computer and tried it again with the same result.  The laptop has no power to it what so ever.  The last time the computer ran, the number and caps lock lights had come on and stayed on, even when the cap locks were off.  Now the computer will not power up.  Does this sound like a motherboard issue or a bad power adapter? 

I appreciate any feedback with this issue.  Thanks........... Mike