Troubleshooting Fluorescent Lights that Do Not Light

five led lights with only the center one lit
  • 1-2 hours
  • Intermediate
  • 0-50
What You'll Need
Voltage tester

Fluorescent lights are often the choice of business offices due to their reliability. They're also found in older homes for the same reason. Fluorescent lights are filled with neon gas that, once electrical current is added, illuminates. In time, fluorescent lights, their fixtures or other small parts will fail or work only sporadically. Read on to learn how to test and identify common causes associated with fluorescent lights that do not illuminate.

Visually Check the Fluorescent Tube

This process involves removing the tube from the fixture, which may require a ladder. If it does, use caution as you work. Once you reach the fixture, you will need to remove the plastic diffuser that covers the tube (if you have one). This may be as simple as pressing up on the plastic, but it may involve removing several screws or clips. Once the light tube is visible, you can conduct your first visual test. If the tube is black or dark gray, then the light is broken and needs to be replaced.

Loose Socket

From here on out, you'll need to observe some safety precautions. The first is to turn off the light at the switch as well as the breaker. Also, when poking around sockets or wires, use a voltage tester to make sure the electricity is off.

Gently push on the tube. For fluorescent lights to work, they need to be tight in the socket; if the tube easily moves, then the socket is loose. Remove the fluorescent light by gripping it at both ends and pulling downward. Set the light tube off to the side. Touch the socket and check to see if it is loose; if it is, correct it by tightening the screws.

Broken, Bent or Oxidized Contacts

You'll be able to easily spot either of these issues. If the prongs of the socket are bent or broken, then you need to replace it. You only need to remove a few screws and disconnect the wires. If the contacts are white, green or covered in dust, you must clean them. Do this by dipping a cotton swab in alcohol and scrubbing the contacts. If the contacts on the outside are not oxidized, remove the socket and inspect the contacts where the wires connect, and clean them in the same manner.

Replace the Starter

Very old fluorescent lights have a starter inside the fixture. They are typically cylindrical and screwed into the fixture below one of the tubes. Press the starter in and twist to remove it and replace it with a new one.


This can be an issue in older homes with fluorescent lights. You'll need to remove the covering, the light tube and the socket in order to see the wires. They have a tendency to oxidize and become brittle. Remove the wires, trim an inch from them and connect a new piece with a wire cap.