if it has a rotating cord, the problem could be the contacts inside the straightener. you will have to open it up until you get to the cord. this usually required you to find the screws that make up the hinge. then remove the rear compartment where the cord enters the device. pull the cord, and move the metal contact points to maximize contact with the metal parts on the cord. replace all parts and plug it in to see if it works.
josh
November 2009