Fluorescent lights are relatively trouble free and use less energy than incandescent lights. A typical fluorescent tube lasts about three years and produces two to four times as much light per watt as a standard incandescent light bulb.
The most frequent problem with a fluorescent light fixture is a worn-out tube. If a fluorescent light fixture begins to flicker or does not light fully, remove and examine the tube. If the tube has bent or broken pins or black discoloration near the ends, replace it. Light gray discoloration is normal in working fluorescent tubes. When replacing an old tube, read the wattage rating printed on the glass surface, and buy a new tube with a matching rating. Never dispose of old tubes by breaking them. Fluorescent tubes contain a small amount of hazardous mercury. Check with your local environmental control agency or health department for disposal guidelines.
Fluorescent light fixtures also can malfunction if the sockets are cracked or worn. Inexpensive replacement sockets are available at any hardware store and can be installed in a few minutes.
If a fixture does not work even after the tube and sockets have been serviced, the ballast probably is defective. Faulty ballasts may leak a black, oily substance and can cause a fluorescent light fixture to make a loud humming sound. Although ballasts can be replaced, always check prices before buying a new ballast. It may be cheaper to purchase and install a new fluorescent fixture rather than to replace the ballast in an old fluorescent light fixture.
A fluorescent light works by directing electrical current through a special gas-filled tube that glows when energized. A white translucent diffuser protects the fluorescent tube and softens the light. A cover plate protects a special transformer, called a ballast. The ballast regulates the flow of 120-volt household current to the sockets. The sockets transfer power to metal pins that extend into the tube.
| Problem | |
| Tube flickers, or lights partially. |
|
| Repair | |
1. Rotate tube to make sure it is seated properly in the sockets. 2. Replace tube and the starter (where present) if tube is discolored or if pins are bent or broken. 3. Replace the ballast if replacement cost is reasonable. Otherwise, replace the entire fixture. | |
| Problem | |
| Tube does not light. |
|
| Repair | |
1. Check wall switch and repair or replace, if needed. 2. Rotate the tube to make sure it is seated properly in sockets. 3. Replace tube and the starter (where present) if tube is discolored or if pins are bent or broken. 4. Replace sockets if they are chipped or if tube does not seat properly. 5. Replace the ballast or the entire fixture. |
|
| Problem | |
| Noticeable black substance around ballast. |
|
| Repair | |
| Replace ballast if replacement cost is reasonable. Otherwise, replace the entire fixture. | |
| Problem | |
| Fixture hums. |
|
| Repair | |
| Replace ballast if replacement cost is reasonable. Otherwise, replace the entire fixture. | |
Tools & Materials 
Screwdriver
Ratchet wrench
Combination tool
Circuit tester
Replacement tubes
Starters, or ballast (if needed)
Replacement fluorescent light fixture (if needed)
Potective equipment
Older fluorescent lights may have a small cylindrical device, called a starter, located near one of the sockets. When a tube begins to flicker, replace both the tube and the starter. Turn off the power, then remove the starter by pushing it slightly and turning counterclockwise. Install a replacement that matches the old starter.
