Can start the mower, but as soon as it revs up, it turns off again. Pretty much by the time the cord goes back in. The silver thing on the side with the holes in it has a black circle on it. Some neighbor kids used it to mow for us last time, hadn't mentioned it stopping. Could it have burned something important when they used it last? Was really hoping to surprise my husband and have the lawn mowed when he got home :-( Is there a way to get it to start and stay on?