No Dell wont send you any intenal spares for any of their products! No matter what you do or say!

They will issue spares out to recognised Dell repair outlets but thats about it.

It would be a lot easier for you to send it away to be fixed as changing a Mo/Bo on a lap top is no where near as straight forward as it is an a PC especially if you havent done it before.

As for your power cord, as someone has already said, as long is it is producing the correct amount of power it will work.

However I dont think that ripping your power cord out would have had any effect on your Mo/Bo (apart from maybe the actual power socket) didnt your battery kick in? It is more likley to have effected your Hard Drive.

What happenes when you try to boot up?