This troubleshooting guide is intended to help the service person quickly diagnose an HID luminaire with magnetic ballast and also ensure that the problem is fixed on the first attempt. This guide addresses the four commonly encountered problems in two manners: 1) Summary of possible actions for those needing only a checklist; and 2) A detailed report on possible actions for those needing additional information. The commonly encountered problems are: a) Lamp on continuously b) Lamp cycles on and off c) Lamp will not start d) Lamp burns dimly