Abstract: A testing device for electrically analyzing electrical failures in high pressure sodium lighting fixtures is disclosed. The testing device is inserted in the lighting fixture after the sodium lamp has been removed and contains three indicator lights. The user of the device compares the condition of the indicator lights with a chart on the label of the device to determine the type of failure. The circuit analyzer device will give distinct indications for a defective lamp, a defective circuit starter board, and a defective ballast and capacitor, thereby allowing the user of the device to make any necessary changes in order to return the lighting fixture to service. A pair of rectifier diodes are installed in a reverse direction so that the pulse to the lamp must be at least 2500 volts in order to break over the diodes PRV rating and to light the appropriate indicating lamps.