AC adapter not recognized

Question

have had my dell inspiron 1525 about 2 weeks - just booted today and got the error message that the ac adapter was not recognized - any help is greatly appreciated - thanks!

Ac adapter of my dell inspiron 1525 is not being recognized. The inside of the thing that connects to the computer looks okay and so does everything else from outside. Nevertheless the black screen always appears saying that it doesn't recognize the AC adapter. I don't understand why this is happening, i've only had this laptop for about six months...