grammyjuju, take a look at the keyboard to make sure the contacts are all nice and clean. Check the keyboard connector on the logic board, make sure that the contacts are clean, not bend and that it is properly inserted. You can clean the contacts with an eraser. Check [http://www.ifixit.com/Answers/View/50068/Burnt+after+wrong+voltage+AC+adapter.|on here] for some more diagrams.