Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. The constant on-off flow of electricity can sometimes loosen a light bulb in the socket. Remove the bulb from the fixture if the bulb is still not illuminating. If it does not illuminate, the bulb is burned out. And a burned fluorescent bulb can not light up anymore. If darkness forms on one side of the tube, rotate the tube by 180 degrees from how it used to sit. Flip the switch and wait a few seconds. If darkness begins to form at the ends of the tube, the bulb may be near its end. If you’re armed with a tape measure, here’s a table to show you how to interoperate the length and diameter of your … If the bulb is the source of the problem, it will not light at all. Scrub the rust and the dust at the holders; 6. Sometimes light bulbs do shatter when they fail. And they're supposed to last 22 years or somesuch. In incandescent bulbs, you can shake the bulb or look at the filament to tell if a bulb is dead without having to put it in a socket. Note the wattage of the bulb to ensure the correct starter is purchased. By checking for surface-level issues, cleaning the parts, and looking at the electronics, you can determine whether you have an easy fix or a trip to the hardware store. When researching your fluorescent bulbs, pay attention to attributes that will help you narrow your options down. Only use lightbulbs that are the proper style and voltage rating for your ballast. When working with electronics, make sure the power source is off to avoid electric shock. Another possible code in this position is 'FC' which would mean that the bulb is a fluorescent circular bulb. A dead fluorescent can be caused by lack of electrical power (tripped breaker or blown fuse), a dead or dying ballast, a dead starter or a dead bulb(s). Install a new ballast, if necessary. Install … Replace it with a fresh one. If so, replace the bulb. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. Bring the bulb vent close to your nose and smell. Bulb vs Lamp. With a CFL, is there any way to tell if a bulb is bad without plugging it into a socket and trying it out? Old starters look no different than new starters, so throw away any starters that have gone bad. Time will tell. While they may still light, they are wearing out and will die soon. If you are interested I can tell you more about tungsten light bulbs and old style wire fuses. wikiHow is where trusted research and expert knowledge come together. Set your multimeter to test the resistance between the two pins Remove one of the working tubes from another fixture and replace it with the suspect tube. Look for dark areas at the base of the bulb. Fluorescent light bulbs typically last many years, but when one flickers on and off, or the end turns light gray to black in color, you'll just need replacement light bulbs. Regardless of whether you're looking to use retrofit or ballast compatible LED tubes in your existing fluorescent fixtures, you'll need to know what kind of ballast your fixture has. If your fluorescent tubes have recently fizzled out – don’t panic. All tip submissions are carefully reviewed before being published. Be careful handling a fluorescent tube. Do not let go of the tube while working with it in the fixture, especially when rotating it. They’re fragile and have potential to break into shards. Look at the end of the bulb for a dark area; if you see one, the bulb is either bad or going bad. It's generally easy to tell when an incandescent bulb has burned out. Include your email address to get a message when this question is answered. Step 1. Check to see if the bulb is tight in the socket. How To Measure Fluorescent Tubes. Change out the fluorescent bulb with a new one. If the darkness only forms on one end of a tube light, flip the tube so the darkened end is on the opposite side of the fixture. When all else fails, the ballast should be replaced. Check for power first then the starter (if applicable) and then the bulbs. What we call a "good burn" for a fluorescent lamp, is one that has lived it's normal life, based on published hours of operation, and is that BOTH ends of the lamp are blackened, or grayed with burn rings. Testing to see if it is good or bad. Check for power first then the starter (if applicable) and then the bulbs. And just to be thorough, you've also checked the main service panel for a tripped breaker or a blown fuse. If you’re still unsure your ballast has bit the dust, then you need to get your hands on a brand new bulb. Before removing a broken bulb from a socket, power to the bulb needs to be turned off. Check your circuit breaker box and confirm that the corresponding breaker is firmly in the "on" position. Please help us continue to provide you with our trusted how-to guides and videos for free by whitelisting wikiHow on your ad blocker. It’s light's out, and you've already determined that a burned-out bulb isn't the culprit. Learn more... A flickering or dead fluorescent bulb can be a nuisance and it may be time to replace it. In that case it would be more appropriate to say the bulb has blown. If testing tube lights, be sure to test both bulbs even if only one is out. Check the main power source for the house and see if the circuit breaker has been tripped or a fuse has blown. For tips on replacing the starter bulb, read on! The pieces must be sealed in a plastic bag then thrown away. If the breaker has been tripped, push the switch entirely to the off position, and flip the switch back on. A bulb/lamp that blows the filament due to a short (such as caused by moisture) will have much more noticeable black scorch inside the quartz lamp near the blown filament. Check the ends of the tube. How can I check the starter of a tube light? In some cases, it is possible to "blow" a new bulb/lamp when an older bulb that requires much less energy to fire, does not "blow". I just replaced the ceiling lights in our kitchen -- 65W standard bulbs replaced by 9W LEDs. By creating an account you agree to the Hunker, The Natural Handyman: Repairing and Troubleshooting Fluorescent Fixtures and Tubes, United Nations Environment Programme: Reducintg RIsk From Mercury. Step 2. You can buy 4-lamp electronic ballasts, and you should be paying well over $15 for a ballast unless you're getting the $2-3 new-stock pulls off ebay, which is my preference. You can also use a multimeter to determine if the electrodes still hold conductivity. Place the probes on both pins of the tube light to get an accurate reading. wikiHow's. To test fluorescent bulbs, start by checking your electrical panel box to confirm the circuit isn't broken. Make sure the power is turned off to avoid any electrical damage. If there is no reading on the multimeter, the bulbs should be replaced. Or in other words, the lifespan of the fluorescent bulb is over. A dead fluorescent can be caused by lack of electrical power (tripped breaker or blown fuse), a dead or dying ballast, a dead starter or a dead bulb (s). Sometimes bulbs "unscrew" themselves or become rotated enough for the electricity not to flow correctly over the end pins. Photo 1 shows how to tell if a fluorescent bulb is bad and how to replace it. Fluorescent tubes are filled with mercury gas and can shatter into very small pieces. By signing up you are agreeing to receive emails according to our privacy policy. How to Tell If a Fluorescent Tube Is Bad? There are some usual reasons a bulb can go bad, and we can do some quick checks to find out if it’s fixable or a replacement is necessary. If there are black rings in the glass nearest the plastic body then the bulb has blown. We know ads can be annoying, but they’re what allow us to make all of wikiHow available for free. LEDS in and of themselves are much more efficient than fluorescent bulbs. Check the ends of the tube. Replace the ballast cover on the fluorescent light fixture. If there is significant yellowed staining of the plastic at the vent where the two glass tubes enter the base then the bulb has blown. We use cookies to make wikiHow great. Check the light bulb first to see if it has burned out. Step 2. How to Remove a Broken Light Bulb. If it has a distinct odour of burnt electronics, then the bulb has blown. http://articles.chicagotribune.com/1988-09-23/entertainment/8802010971_1_tube-fluorescent-sockets, https://www.naturalhandyman.com/iip/infelectrical/inffluor.html, https://sciencing.com/why-do-fluorescent-lights-flicker-5031263.html, consider supporting our work with a contribution to wikiHow. So, if you see a darker tone on the ends of the bulb or the tube, that means the bulb has been burned off. This article has been viewed 52,369 times. When all else fails, the ballast should be replaced. Gabrielle Black has been a professional writer, artist and designer since 2002. For retrofit LED tubes, you'll be re-wiring your fixture to bypass the existing ballast, and just how that re- Let’s show you how to tell if a fluorescent bulb is bad. How do you easily tell if a CFL bulb is bad? % of people told us that this article helped them. Visually inspect ; 3. If it illuminates, the suspect ballast, starter, or fixture may need to be replaced. When using direct fit LEDs, the ballast is still using energy and eating into your possible energy savings. If the bulb still does not light, the gas may have leaked out and the bulb will need to be replaced. If they appear darkened this indicates the bulb is burned out. How to Tell If Fluorescent Bulbs Are Blown? Check if the bulb is working in another lamp; 5. Tubes can fall out of a fixture if not properly installed. When light bulbs shatter as the failure mode then there has probably been a power surge. 'FB' or 'FU' indicate that the bulb is 'bent' or 'U-shaped,' depending on the bulb manufacturer. What do you do next? Unlike fluorescent tubes, LEDs don’t require a ballast to regulate current. Currents travel between both tubes and either could be causing the problem. Replace the bulb with the same size bulb. Step 1. When a fluorescent tube burns out, a black spot appears on the inside of the bulb over one of its electrodes near one end of the tube. Step 3. By using our site, you agree to our. I don't have a lot of faith in the $10-tier LED replacement "tubes", and their CRI is not up to where real fluorescent tubes are. Rotate the tube in the fixture if the bulb is not darkened on either end. Many of us don’t pay attention to our light bulbs until they burn out and when they do, it can be difficult to know exactly which size, shape or style you need to replace the bulb in your fitting exactly. Simply look at the filament to see if it is broken, or give the bulb a gentle shake to listen for the familiar "tinkle tinkle" of the broken filament in the bulb. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. Check if the connecting pins are broken or bent; 4. Loading... Autoplay When autoplay is enabled, a suggested video will automatically play next. You can easily tell if a fluorescent bulb is burned or not. Up next The burned fluorescent bulb has a darker end of it. Other Problems That Can Be Identified and Fixed with The Above Checks All of these lamps use the same technology as linear fluorescent tubes but are wrapped into shapes which make them more suitable for smaller spaces. Checking a common light bulb using a multimeter on the ohm scale. If they appear darkened this indicates the bulb is burned out. You must test the fluorescent bulb before considering a replacement. Another common … You will usually … Well, first you need to find out if power is actually getting to the light socket. Always buy quality brands if you value your time. If the fluorescent bulb fails to come on, turn the switch off. CFLs come in a number of shapes, the most common being twin tubes, quads, triples, spirals, F type lamps, 2D lamps and circular lamps. Knowing the type of fluorescent light you will use with your ballast is a good start to your search. Hunker may earn compensation through affiliate links in this story. Electricians usually refer to a light bulb as a lamp. References. If you really can’t stand to see another ad again, then please consider supporting our work with a contribution to wikiHow. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Light bulb manufacturers use the term “lamp” when referring to fluorescent lights. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Identifying the viability of a fluorescent bulb is somewhat more complicated. And they're just as bright, if not brighter. Last Updated: March 29, 2019 Bulbs are the most common problem with a bad fluorescent fixture. For tips on replacing the starter bulb, read on! Thanks to all authors for creating a page that has been read 52,369 times. If you are installing a tube-style fluorescent bulb, be sure the pins on each end are in contact with the ballast's socket. Lamp Type. A dead fluorescent can be caused by lack of electrical power (tripped breaker or blown fuse), a dead or dying ballast, a dead starter or a dead bulb(s). Her theatrical designs, puppet design and construction have been featured in "Theatre Design & Technology" magazine and she has written numerous articles for various websites. Before going out to purchase a new bulb, ensure the bulb is the main problem. Make sure the lamp is plugged into a functioning electrical outlet, and then check for damage to the bulb itself. If there is no reading on the multimeter, the bulbs should be replaced. If that happens, the Environment Protection Agency recommends airing out the location of the breakage, then picking up the pieces with a damp paper cloth. 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