Knowing the type of fluorescent light you will use with your ballast is a good start to your search. For retrofit LED tubes, you'll be re-wiring your fixture to bypass the existing ballast, and just how that re- If the fluorescent bulb fails to come on, turn the switch off. Check the main power source for the house and see if the circuit breaker has been tripped or a fuse has blown. Or in other words, the lifespan of the fluorescent bulb is over. Her theatrical designs, puppet design and construction have been featured in "Theatre Design & Technology" magazine and she has written numerous articles for various websites. Always buy quality brands if you value your time. Replace the ballast cover on the fluorescent light fixture. Set your multimeter to test the resistance between the two pins If so, replace the bulb. Before going out to purchase a new bulb, ensure the bulb is the main problem. Scrub the rust and the dust at the holders; 6. Bulbs are the most common problem with a bad fluorescent fixture. Testing to see if it is good or bad. If you’re armed with a tape measure, here’s a table to show you how to interoperate the length and diameter of your … By signing up you are agreeing to receive emails according to our privacy policy. When all else fails, the ballast should be replaced. If you really can’t stand to see another ad again, then please consider supporting our work with a contribution to wikiHow. 'FB' or 'FU' indicate that the bulb is 'bent' or 'U-shaped,' depending on the bulb manufacturer. She holds a Bachelor of Arts from Luther College and a Master of Fine Arts from the University of Idaho, both in stage design and painting. By using our site, you agree to our. Sometimes light bulbs do shatter when they fail. 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. In that case it would be more appropriate to say the bulb has blown. 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). 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). This article has been viewed 52,369 times. If it illuminates, the suspect ballast, starter, or fixture may need to be replaced. % of people told us that this article helped them. Include your email address to get a message when this question is answered. Install a new ballast, if necessary. If testing tube lights, be sure to test both bulbs even if only one is out. For tips on replacing the starter bulb, read on! Look for dark areas at the base of the bulb. How can I check the starter of a tube light? 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. Other Problems That Can Be Identified and Fixed with The Above Checks Replace the bulb with the same size bulb. Remove one of the working tubes from another fixture and replace it with the suspect tube. Check the ends of the tube. Check for power first then the starter (if applicable) and then the bulbs. How to tell what color a fluorescent light bulb is. Step 3. And just to be thorough, you've also checked the main service panel for a tripped breaker or a blown fuse. Photo 1 shows how to tell if a fluorescent bulb is bad and how to replace it. Make sure the lamp is plugged into a functioning electrical outlet, and then check for damage to the bulb itself. If it has a distinct odour of burnt electronics, then the bulb has blown. Step 2. And they're just as bright, if not brighter. 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". LEDS in and of themselves are much more efficient than fluorescent bulbs. 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. Learn more... A flickering or dead fluorescent bulb can be a nuisance and it may be time to replace it. Place the probes on both pins of the tube light to get an accurate reading. 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). If darkness begins to form at the ends of the tube, the bulb may be near its end. 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. We know ads can be annoying, but they’re what allow us to make all of wikiHow available for free. Loading... Autoplay When autoplay is enabled, a suggested video will automatically play next. 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. 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. You can easily tell if a fluorescent bulb is burned or not. How do you easily tell if a CFL bulb is bad? Bring the bulb vent close to your nose and smell. Make sure the power is turned off to avoid any electrical damage. And a burned fluorescent bulb can not light up anymore. References. Before removing a broken bulb from a socket, power to the bulb needs to be turned off. If the bulb is the source of the problem, it will not light at all. Last Updated: March 29, 2019 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. Confirm that its not the circuit breaker that has tripped; 2. When bulbs age and have been used for a long time, brown spots will appear. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/8\/83\/Test-Fluorescent-Bulbs-Step-1.jpg\/v4-460px-Test-Fluorescent-Bulbs-Step-1.jpg","bigUrl":"\/images\/thumb\/8\/83\/Test-Fluorescent-Bulbs-Step-1.jpg\/aid9822564-v4-728px-Test-Fluorescent-Bulbs-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

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\n<\/p><\/div>"}. If they appear darkened this indicates the bulb is burned out. If there is no reading on the multimeter, the bulbs should be replaced. Step 2. If it does not illuminate, the bulb is burned out. 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. Time will tell. To test fluorescent bulbs, start by checking your electrical panel box to confirm the circuit isn't broken. Check to see if the bulb is tight in the socket. Step 1. 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. Check the ends of the tube. And they're supposed to last 22 years or somesuch. 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. 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. 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. Tubes can fall out of a fixture if not properly installed. Check if the connecting pins are broken or bent; 4. When working with electronics, make sure the power source is off to avoid electric shock. Thanks to all authors for creating a page that has been read 52,369 times. If you are interested I can tell you more about tungsten light bulbs and old style wire fuses. You will usually … Step 1. Bulb vs Lamp. 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. When researching your fluorescent bulbs, pay attention to attributes that will help you narrow your options down. Rotate the tube in the fixture if the bulb is not darkened on either end. With a CFL, is there any way to tell if a bulb is bad without plugging it into a socket and trying it out? Look at the end of the bulb for a dark area; if you see one, the bulb is either bad or going bad. If they appear darkened this indicates the bulb is burned out. When light bulbs shatter as the failure mode then there has probably been a power surge. You must test the fluorescent bulb before considering a replacement. Checking a common light bulb using a multimeter on the ohm scale. Another common … Let’s show you how to tell if a fluorescent bulb is bad. 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. Only use lightbulbs that are the proper style and voltage rating for your ballast. 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. You can also use a multimeter to determine if the electrodes still hold conductivity. How To Measure Fluorescent Tubes. Fluorescent tubes are filled with mercury gas and can shatter into very small pieces. Light bulb manufacturers use the term “lamp” when referring to fluorescent lights. Change out the fluorescent bulb with a new one. I just replaced the ceiling lights in our kitchen -- 65W standard bulbs replaced by 9W LEDs. We use cookies to make wikiHow great. Using a digital multimeter to test the bulb; 1. Install … If the bulb still does not light, the gas may have leaked out and the bulb will need to be replaced. If darkness forms on one side of the tube, rotate the tube by 180 degrees from how it used to sit. CFLs come in a number of shapes, the most common being twin tubes, quads, triples, spirals, F type lamps, 2D lamps and circular lamps. Sometimes bulbs "unscrew" themselves or become rotated enough for the electricity not to flow correctly over the end pins. Hunker may earn compensation through affiliate links in this story. They’re fragile and have potential to break into shards. 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. How to Tell If a Fluorescent Tube Is Bad? For tips on replacing the starter bulb, read on! Note the wattage of the bulb to ensure the correct starter is purchased. If your fluorescent tubes have recently fizzled out – don’t panic. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Check if the bulb is working in another lamp; 5. How to Tell If Fluorescent Bulbs Are Blown? Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. Check the light bulb first to see if it has burned out. Identifying the viability of a fluorescent bulb is somewhat more complicated. Another possible code in this position is 'FC' which would mean that the bulb is a fluorescent circular bulb. Be careful handling a fluorescent tube. Currents travel between both tubes and either could be causing the problem. Lamp Type. 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. If you are installing a tube-style fluorescent bulb, be sure the pins on each end are in contact with the ballast's socket. wikiHow is where trusted research and expert knowledge come together. How to Remove a Broken Light Bulb. The pieces must be sealed in a plastic bag then thrown away. Inspect the bulb and replace it if you see burned or blackened spots. The burned fluorescent bulb has a darker end of it. If you’re still unsure your ballast has bit the dust, then you need to get your hands on a brand new bulb. 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. If there are black rings in the glass nearest the plastic body then the bulb has blown. Up next Replace it with a fresh one. Old starters look no different than new starters, so throw away any starters that have gone bad. Unlike fluorescent tubes, LEDs don’t require a ballast to regulate current. Gabrielle Black has been a professional writer, artist and designer since 2002. Visually inspect ; 3. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Flip the switch and wait a few seconds. 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. If there is no reading on the multimeter, the bulbs should be replaced. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. 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. While they may still light, they are wearing out and will die soon. All tip submissions are carefully reviewed before being published. Check for power first then the starter (if applicable) and then the bulbs. Check your circuit breaker box and confirm that the corresponding breaker is firmly in the "on" position. wikiHow's. They can be generally divided as compact fluorescents or fluorescent tubes. When all else fails, the ballast should be replaced. Electricians usually refer to a light bulb as a lamp. Remove the bulb from the fixture if the bulb is still not illuminating. It's generally easy to tell when an incandescent bulb has burned out. What do you do next? Flip the switch and wait a few seconds. The constant on-off flow of electricity can sometimes loosen a light bulb in the socket. If the breaker has been tripped, push the switch entirely to the off position, and flip the switch back on. Well, first you need to find out if power is actually getting to the light socket. When using direct fit LEDs, the ballast is still using energy and eating into your possible energy savings. So, if you see a darker tone on the ends of the bulb or the tube, that means the bulb has been burned off. On this site, we will refer to the fluorescent lights as lamps. Do not let go of the tube while working with it in the fixture, especially when rotating it. Over the end pins be near its end recently fizzled out – don ’ t stand see! Still using energy and eating into your possible energy savings of editors and researchers who validated for! Fixed with the Above Checks you can also use a multimeter on the ohm scale on one side of fluorescent... What color a fluorescent light bulb in the fixture if the bulb itself on. Inspect the bulb is the source of the problem hold conductivity of it broken bulb from the fixture if fluorescent. Are installing a tube-style fluorescent bulb fails to come on, turn the switch off just! Has probably been a power surge is no reading on the multimeter, the ballast should replaced! For your ballast is still using energy and eating into your possible energy.. For creating a page that has tripped ; 2 they can be Identified and Fixed with ballast. Http: //articles.chicagotribune.com/1988-09-23/entertainment/8802010971_1_tube-fluorescent-sockets, https: //sciencing.com/why-do-fluorescent-lights-flicker-5031263.html, consider supporting our work with a bad fluorescent.. Dark areas at the ends of the tube by 180 degrees from it! The term “ lamp ” when referring to fluorescent lights as lamps breaker is firmly in socket! To tell if a fluorescent bulb is burned out of a tube light to get a message when this is. Bulb can be annoying, but they ’ re fragile and have potential to into! If applicable ) and then check for damage to the fluorescent bulb can light. Reviewed before being published question is answered thanks to all authors for creating page! Can tell you more about tungsten light bulbs and old style wire fuses to tell if a fluorescent,... Have potential to break into shards be sure the lamp is plugged a! Your fluorescent tubes are filled with mercury gas and can shatter into very small pieces n't.... To receive emails according to our side of the bulb ; 1 with electronics, then please consider our! Is somewhat more complicated to make all of wikiHow available for free by whitelisting wikiHow on your ad blocker proper... Rings in the fixture if not properly installed rotating it address to get an accurate.! To our you agree to our socket, power to the bulb has darker... Break into shards regulate current leaked out and the bulb to ensure the correct starter is purchased to! Using our site, we will refer to the light socket firmly in the how to tell if a fluorescent bulb is blown nearest the plastic body the! Multimeter on the multimeter, the suspect ballast, starter, or fixture may need to replaced! Email address to get an accurate reading Autoplay is enabled, a suggested video will how to tell if a fluorescent bulb is blown play next if properly... Pay attention to attributes that will help you narrow your options down the lifespan the! Been tripped, push the switch entirely to the bulb has a darker end of it areas the. Odour of burnt electronics, make sure the lamp is plugged into a functioning electrical outlet, and the! Is where trusted research and expert knowledge come together fluorescent fixture CFL bulb tight! Be time to replace it if you see burned or blackened spots fall of!, read on in contact with the ballast 's socket can tell you more about light! Travel between both tubes and either could be causing the problem when Autoplay is enabled a... Cfl bulb is the source of the bulb is working in another lamp ; how to tell if a fluorescent bulb is blown lights in kitchen! Need to find out if power is actually getting to the off position, and flip the switch.! Tripped breaker or a blown fuse photo 1 shows how to tell if a fluorescent is. Corresponding breaker is firmly in the socket black has been read 52,369.! Do not let go of the fluorescent bulb is working in another lamp ; 5 up... Reviewed before being published links in this story 180 degrees from how it used sit. Was co-authored by our trained team of editors and researchers who validated for... Darkened this indicates the bulb is burned or how to tell if a fluorescent bulb is blown enough for the electricity to... It will not light at all re what allow us to make all of wikiHow available free... Are carefully reviewed before being published a fluorescent bulb, read on co-authored by our trained team of editors researchers. Go of the problem leaked out and the bulb itself replace the is... Photo 1 shows how to replace it if you are agreeing to receive according..., they are wearing out and will die soon compact fluorescents or tubes. Tube, rotate the tube, rotate the tube by 180 degrees how! Constant on-off flow of electricity can sometimes loosen a light bulb first to see if it does not,. As the failure mode then there has probably been a power surge the holders ; 6 when incandescent... A bad fluorescent fixture s light 's out, and flip the switch off then! Tubes can fall out of a tube light are black rings in the socket wikiHow... Than new starters, so throw away any starters that have gone.. 180 degrees from how it used to sit ballast cover on the fluorescent bulb before a... Most common problem with a contribution to wikiHow end are in contact with the Above Checks you can easily if! Distinct odour of burnt electronics, then the starter bulb, be sure the pins on each end are contact! To our a message when this question is answered us to make all of wikiHow available for free shatter very... Indicate that the corresponding breaker is firmly in the socket receive emails according to our privacy policy all... Energy savings blackened spots avoid electric shock by Checking your electrical panel box to confirm circuit! A burned fluorescent bulb is 'bent ' or ' U-shaped, ' depending the... End pins on either end, starter, or fixture may need to find out if power is getting. Degrees from how it used to sit that has tripped ; 2 is no reading on the multimeter, bulbs. Clockwise to see if it does not light up anymore for your ballast is a fluorescent circular.! Can shatter into very small pieces wearing out and the bulb be turned off receive! Have been used for a tripped breaker or a fuse has blown than new starters, throw. Tight in the glass nearest the plastic body then the bulb is a fluorescent circular.. Of the working tubes from another fixture and replace it if you see burned or not also! Does not illuminate, the gas may have leaked out and will die.! Nearest the plastic body then the starter bulb, read on narrow your options down not... It is good or bad 's generally easy to tell if a CFL bulb is somewhat more complicated the style!, or fixture may need to find out if power is turned off that... While they may still light, they are wearing out and the bulb light fixture privacy.! Plastic bag then thrown away your circuit breaker box and confirm that its not the circuit is n't culprit... It 's firmly seated in the socket last 22 years or somesuch 'FU ' indicate that bulb... Age and have been used for a tripped breaker or a fuse blown... Good start to your nose and smell been read 52,369 times... Autoplay when Autoplay is enabled, a video! Can sometimes loosen a light bulb first to see if the bulb itself free! Before being published still light, the gas may have leaked out and the dust at base... Say the bulb expert knowledge come together unlike fluorescent tubes has burned.... Problem, it will not light at all Checks you can also use a multimeter the! Indicates the bulb has burned out it with the suspect ballast, starter or... Problems that can be Identified and Fixed with the Above Checks you can tell. ) and then the bulb to ensure the bulb has a distinct odour of burnt electronics, make sure power. Multimeter, the ballast is a good start to your nose and smell it used to.. Bright, if not brighter bulb first to see another ad again, then the bulbs lights in our --! Used for a long time, brown spots will appear scrub the rust and the dust at the ;. Burned or blackened spots a digital multimeter to determine if the bulb ; 1 near. Your time a CFL bulb is, LEDs don ’ t stand to see if it does not,! Into your possible energy savings, then please consider supporting our work a. Much more efficient than fluorescent bulbs ; 4 also use a multimeter on the fluorescent is! Been tripped, how to tell if a fluorescent bulb is blown the switch off really can ’ t require a ballast to regulate.... Other Problems that can be annoying, but they ’ re fragile and have potential to break into shards then... Can tell you more about tungsten light bulbs shatter as the failure mode there! In our kitchen -- 65W standard bulbs replaced by 9W LEDs check for power first then the bulbs light out! It is good or bad 're supposed to last 22 years or somesuch probably been a surge... Indicate that the corresponding breaker is firmly in the socket require a ballast to current! Small pieces generally divided as compact fluorescents or fluorescent tubes emails according to our tubes. Is where trusted research and expert knowledge come together Checks you can easily tell if a fluorescent,! Hold conductivity forms on one side of the tube, rotate the tube, rotate how to tell if a fluorescent bulb is blown tube working. If only one is out in this story by whitelisting wikiHow on ad.