A neon light is also known as a luminous tube. This form of lighting is frequently used for signs. The basic design of the neon light is a glass tube with an electrode at one end. The glass tube is full of an inert gas, in this case neon. When a high voltage power source is connected to the light, it will glow. Neon light occurs when voltage causes the gas molecules to lose or gain electrons. There are several troubleshooting steps you can take should your neon light not work properly.
Check the voltage supply to the light and look for any loose connections. Low power will cause a blinking or flickering neon light. You may need to use a step-up transformer if the voltage to the light is not high enough. Use a multimeter to check the voltage on all electrical spots.
Look for broken wires, a shorted wire, extremely low voltage or defective tube section within the neon light system. Shorts and broken wires will not transfer any voltage to the light. If several neon lights are connected in a series and one is broken then none of the lights will work. Find and replace the broken section.
Check for any leaks along the glass tube. Neon leaking out of the tube will result in a dim light, and air going into the bulb will kill any light as the neon no longer forms ions. A leaky tube is very difficult to fix. Some lighting stores will break and refill the tube but in the long run it is easier and less expensive to throw away the leaky tube and get a new one.
Check that the transformer is still working properly. A bad transformer can cause many different problems. The easiest way to fix this problem is to get a new transformer. Make sure the new transformer meets the output voltage needed to power the neon light.