during assembly of the incandescent lamps is to be noted that the bare wire of the incandescent lamp is inserted along with the black insulated wire into the tube. The brown ground wire (with resistor) should be stripped to a length of 20 mm. Then he is pushed as far as the stripped end of the bottom of the mast. Both cables at the lower end of the mast should be twisted so that they do not slip out. Both cables are then connected to the transformer (14-16 V AC/DC) via plus and minus. For a better threading helps baby powder. With this powder you must rubb the cable.