Troubleshooting a light fixture can prove to be a difficult task. Several elements of a light fixture can fail, causing it to malfunction. When troubleshooting a light fixture, start with the easiest possible solution and work your way through, saving the hardest part to diagnose for last. By the process of elimination, you may be able to repair the fixture yourself and save the money required to hire an electrician.
Before attempting to troubleshoot a light fixture, make sure to turn off the power supplying the fixture. Simply turning off the wall switch supplying the fixture does not guarantee that a live circuit is not present in the fixture's electrical box. Testing the wires in the electrical box with a noncontact voltage meter helps you to verify the electric current is indeed off. Probes attached to the meter are used near wires in the electrical box to check for electrical current. If you are unsure the electricity is off, turn off the main breaker supplying the whole house at the circuit breaker box.
Make sure you are using the correct type and size of light bulbs in the fixture. This is especially important with fluorescent and LED (light-emitting diode) fixtures. Replace the light bulbs in the fixture. Sometimes a light bulb will work initially and fail after it has been on for a while. This is due to the filament curling and losing contact after it has had a chance to heat up. When the filament cools down, it can re-establish contact and once again function properly.
Common problems with a fixture's electrical wiring are found in the electrical box. You will have to remove any mounting screws securing the fixture to the electrical box to expose the wires. A loose or disconnected wire could cause the fixture to malfunction. It is also possible that a problem exists in the switch or its wiring. Switches can wear out over an extended period. The wires in the electrical box supplying the switch can also become loose or disconnected. When you cannot determine a wiring problem visually, it may be necessary to turn on the power supply to the fixture at the circuit breaker box and use the voltage meter to verify electricity is reaching the fixture or its switch.
Traditional light fixtures are not prone to malfunction. But there are certain problems that can develop in a fluorescent fixture that can cause it to malfunction. Fluorescent light fixture failure usually relates to the fluorescent bulbs or the ballast. A visual inspection of the fixture can help to determine if it is bad. Ballasts use oil to help keep the unit cool; when they start to leak, ballast failure is sure to follow. Another area to inspect on the fluorescent fixtures is the lamp holder. As the fixture ages, the plastic lamp holder can become brittle. This leads to cracking, causing the bulbs to lose contact. Although traditional fixtures are simple devices, a few problems can develop with older models. Light bulb socket failure and a bad wire within the fixture are the two most common culprits.
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