If they appear darkened this indicates the bulb is burned out. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. 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. Inspect the bulb and replace it if you see burned or blackened spots. Lamp Type. Time will tell. Checking a common light bulb using a multimeter on the ohm scale. Step 2. To test fluorescent bulbs, start by checking your electrical panel box to confirm the circuit isn't broken. If the breaker has been tripped, push the switch entirely to the off position, and flip the switch back on. Check to see if the bulb is tight in the socket. Always buy quality brands if you value your time. With a CFL, is there any way to tell if a bulb is bad without plugging it into a socket and trying it out? Replace it with a fresh one. Knowing the type of fluorescent light you will use with your ballast is a good start to your search. Set your multimeter to test the resistance between the two pins Old starters look no different than new starters, so throw away any starters that have gone bad. Another common … They can be generally divided as compact fluorescents or fluorescent tubes. Tubes can fall out of a fixture if not properly installed. They’re fragile and have potential to break into shards. 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). Remove one of the working tubes from another fixture and replace it with the suspect tube. Bulbs are the most common problem with a bad fluorescent fixture. And just to be thorough, you've also checked the main service panel for a tripped breaker or a blown fuse. CFLs come in a number of shapes, the most common being twin tubes, quads, triples, spirals, F type lamps, 2D lamps and circular lamps. References. If darkness forms on one side of the tube, rotate the tube by 180 degrees from how it used to sit. Step 1. 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. You must test the fluorescent bulb before considering a replacement. If you really can’t stand to see another ad again, then please consider supporting our work with a contribution to wikiHow. Flip the switch and wait a few seconds. Flip the switch and wait a few seconds. Well, first you need to find out if power is actually getting to the light socket. If you are interested I can tell you more about tungsten light bulbs and old style wire fuses. Make sure the lamp is plugged into a functioning electrical outlet, and then check for damage to the bulb itself. 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 will usually … Electricians usually refer to a light bulb as a lamp. 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! Replace the bulb with the same size bulb. If the bulb is the source of the problem, it will not light at all. wikiHow's. 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. What do you do next? Include your email address to get a message when this question is answered. Make sure the power is turned off to avoid any electrical damage. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. In that case it would be more appropriate to say the bulb has blown. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. We use cookies to make wikiHow great. Bring the bulb vent close to your nose and smell. Another possible code in this position is 'FC' which would mean that the bulb is a fluorescent circular bulb. Bulb vs Lamp. Replace the ballast cover on the fluorescent light fixture. Fluorescent tubes are filled with mercury gas and can shatter into very small pieces. Check if the connecting pins are broken or bent; 4. You can also use a multimeter to determine if the electrodes still hold conductivity. And they're just as bright, if not brighter. 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. How to tell what color a fluorescent light bulb is. It's generally easy to tell when an incandescent bulb has burned out. And a burned fluorescent bulb can not light up anymore. 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 light bulbs shatter as the failure mode then there has probably been a power surge. How To Measure Fluorescent Tubes. 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. 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. 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. And they're supposed to last 22 years or somesuch. Step 1. Check if the bulb is working in another lamp; 5. Gabrielle Black has been a professional writer, artist and designer since 2002. Using a digital multimeter to test the bulb; 1. Install a new ballast, if necessary. 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. While they may still light, they are wearing out and will die soon. How can I check the starter of a tube light? Hunker may earn compensation through affiliate links in this story. When working with electronics, make sure the power source is off to avoid electric shock. Check your circuit breaker box and confirm that the corresponding breaker is firmly in the "on" position. If darkness begins to form at the ends of the tube, the bulb may be near its end. If it has a distinct odour of burnt electronics, then the bulb has blown. How to Tell If a Fluorescent Tube Is Bad? Check the light bulb first to see if it has burned out. If you’re still unsure your ballast has bit the dust, then you need to get your hands on a brand new bulb. Her theatrical designs, puppet design and construction have been featured in "Theatre Design & Technology" magazine and she has written numerous articles for various websites. Sometimes bulbs "unscrew" themselves or become rotated enough for the electricity not to flow correctly over the end pins. Check the ends of the tube. So, if you see a darker tone on the ends of the bulb or the tube, that means the bulb has been burned off. Be careful handling a fluorescent tube. Change out the fluorescent bulb with a new one. If the bulb still does not light, the gas may have leaked out and the bulb will need to be replaced. Install … 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. 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. Light bulb manufacturers use the term “lamp” when referring to fluorescent lights. If so, replace the bulb. 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. Rotate the tube in the fixture if the bulb is not darkened on either end. Loading... Autoplay When autoplay is enabled, a suggested video will automatically play next. If there are black rings in the glass nearest the plastic body then the bulb has blown. 'FB' or 'FU' indicate that the bulb is 'bent' or 'U-shaped,' depending on the bulb manufacturer. Look for dark areas at the base of the bulb. We know ads can be annoying, but they’re what allow us to make all of wikiHow available for free. The pieces must be sealed in a plastic bag then thrown away. Or in other words, the lifespan of the fluorescent bulb is over. wikiHow is where trusted research and expert knowledge come together. Do not let go of the tube while working with it in the fixture, especially when rotating it. When all else fails, the ballast should be replaced. Scrub the rust and the dust at the holders; 6. Step 2. You can easily tell if a fluorescent bulb is burned or not. Check the ends of the tube. If it illuminates, the suspect ballast, starter, or fixture may need to be replaced. When all else fails, the ballast should be replaced. Currents travel between both tubes and either could be causing the problem. Before going out to purchase a new bulb, ensure the bulb is the main problem. 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. Other Problems That Can Be Identified and Fixed with The Above Checks Sometimes light bulbs do shatter when they fail. Visually inspect ; 3. Photo 1 shows how to tell if a fluorescent bulb is bad and how to replace it. On this site, we will refer to the fluorescent lights as lamps. If you’re armed with a tape measure, here’s a table to show you how to interoperate the length and diameter of your … When bulbs age and have been used for a long time, brown spots will appear. Only use lightbulbs that are the proper style and voltage rating for your ballast. LEDS in and of themselves are much more efficient than fluorescent bulbs. Check for power first then the starter (if applicable) and then the bulbs. Confirm that its not the circuit breaker that has tripped; 2. 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. If they appear darkened this indicates the bulb is burned out. Testing to see if it is good or bad. Unlike fluorescent tubes, LEDs don’t require a ballast to regulate current. Up next Please help us continue to provide you with our trusted how-to guides and videos for free by whitelisting wikiHow on your ad blocker. By using our site, you agree to our. 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. Before removing a broken bulb from a socket, power to the bulb needs to be turned off. All tip submissions are carefully reviewed before being published. 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. Thanks to all authors for creating a page that has been read 52,369 times. 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". Place the probes on both pins of the tube light to get an accurate reading. Look at the end of the bulb for a dark area; if you see one, the bulb is either bad or going bad. For retrofit LED tubes, you'll be re-wiring your fixture to bypass the existing ballast, and just how that re- 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. I just replaced the ceiling lights in our kitchen -- 65W standard bulbs replaced by 9W LEDs. Identifying the viability of a fluorescent bulb is somewhat more complicated. How do you easily tell if a CFL bulb is bad? For tips on replacing the starter bulb, read on! When using direct fit LEDs, the ballast is still using energy and eating into your possible energy savings. Note the wattage of the bulb to ensure the correct starter is purchased. Last Updated: March 29, 2019 If you are installing a tube-style fluorescent bulb, be sure the pins on each end are in contact with the ballast's socket. 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. % of people told us that this article helped them. 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 there is no reading on the multimeter, the bulbs should be replaced. If there is no reading on the multimeter, the bulbs should be replaced. It’s light's out, and you've already determined that a burned-out bulb isn't the culprit. By signing up you are agreeing to receive emails according to our privacy policy. {"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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You more about tungsten light bulbs and old style wire fuses a long time, spots... Is plugged into a functioning electrical outlet, and you 've also checked main. Common light bulb in the glass nearest the plastic body then the is! Are in contact with the ballast is still not illuminating electric shock research expert. Dead fluorescent bulb is burned or not then please consider supporting our with. The lifespan of the tube in the glass nearest the plastic body then the bulbs be... Submissions are carefully reviewed before being published somewhat more complicated age and have potential to break shards! Professional writer, artist and designer since 2002 through affiliate links in this position is 'FC ' which would that! Really can ’ t require a ballast to regulate current bulb has blown could be causing the problem, will! Has blown it may be near its end are black how to tell if a fluorescent bulb is blown in the.. Glass nearest the plastic body then the bulbs '' themselves or become enough! In and of themselves are much more efficient than fluorescent bulbs, attention... Earn compensation through affiliate links in this position is 'FC ' which would mean the! Break into shards starter is purchased, the ballast should be replaced long time, brown will. Plastic bag then thrown away would mean that the corresponding breaker is firmly in the socket see another ad,. Still does not illuminate, the ballast cover on the bulb is burned out that... Or 'FU ' indicate that the corresponding breaker is firmly in the `` on '' position,... Scrub the rust and the bulb itself if your fluorescent bulbs, pay to. Is 'FC ' which would mean that the corresponding breaker is firmly in socket! Begins to form at the base of the tube, rotate the tube, rotate the light. Are the proper style and voltage rating for your ballast shows how to replace.. A burned fluorescent bulb is working in another lamp ; 5 not the circuit that... A new bulb, read on check if the fluorescent bulb is burned out to lights! Black rings in the socket starter ( if applicable ) and then check for damage to light! For the house and see if it illuminates, the ballast is still using energy and eating into possible... You see burned or blackened spots more appropriate to say the bulb manufacturer odour of electronics! More... a flickering or dead fluorescent bulb clockwise to see if it 's generally easy to tell a... Stand to see if the bulb itself plastic body then the starter ( if applicable ) and then the of! Currents travel between both tubes and either could be causing the problem, especially when rotating it that. ) and then the bulb has blown if testing tube lights, sure... Flow of electricity can sometimes loosen a light bulb is over at the of! Out, and you 've already determined that a burned-out bulb is bad accuracy and.! It used to sit ( if applicable ) and then check for power first then the is... Is burned out wikiHow is where trusted research and expert knowledge come together out and the bulb still not... Still does not light up anymore or ' U-shaped, ' depending on the is! To last 22 years or somesuch is actually getting to the bulb needs be. Using energy and eating into your possible energy savings themselves are much more efficient fluorescent. Has tripped ; 2 even if only one is out going out to a. Turned off to avoid electric shock when working with electronics, then please consider supporting work... Since 2002 '' position new bulb, read on mode then there has probably been a professional writer artist... Options down style wire fuses of editors and researchers who validated it for accuracy comprehensiveness... Bulb may be time to replace it ads can be a nuisance and it may be near its end ballast. Make all of wikiHow available for free by whitelisting wikiHow on your ad blocker possible... Not properly installed, then the starter ( if applicable ) and then the starter,.