Its hard to say what it is, it oculd be something simple like a bad solder or twist joint, or it oculd be a burned out LED, but either way, I would call who ever made the component (Canopy) a its probably warranted if its a major manufacturer, and make a warranty claim if its under warranty yet. Some like coralife are great at it, and they will send out a new replacement part orentire light assembly and pay to have the other picked up by a shipper.