Note the wattage of the bulb to ensure the correct starter is purchased. 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. Before removing a broken bulb from a socket, power to the bulb needs to be turned off. 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. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. How to tell what color a fluorescent light bulb is. You can also use a multimeter to determine if the electrodes still hold conductivity. Install … When all else fails, the ballast should be replaced. We know ads can be annoying, but they’re what allow us to make all of wikiHow available for free. Remove one of the working tubes from another fixture and replace it with the suspect tube. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. wikiHow is where trusted research and expert knowledge come together. For tips on replacing the starter bulb, read on! References. Bulbs are the most common problem with a bad fluorescent fixture. Step 2. And they're just as bright, if not brighter. So, if you see a darker tone on the ends of the bulb or the tube, that means the bulb has been burned off. While they may still light, they are wearing out and will die soon. Checking a common light bulb using a multimeter on the ohm scale. Do not let go of the tube while working with it in the fixture, especially when rotating it. 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. Make sure the lamp is plugged into a functioning electrical outlet, and then check for damage to the bulb itself. Learn more... A flickering or dead fluorescent bulb can be a nuisance and it may be time to replace it. Check the ends of the tube. Check the main power source for the house and see if the circuit breaker has been tripped or a fuse has blown. How to Tell If a Fluorescent Tube Is Bad? All tip submissions are carefully reviewed before being published. Unlike fluorescent tubes, LEDs don’t require a ballast to regulate current. In that case it would be more appropriate to say the bulb has blown. The constant on-off flow of electricity can sometimes loosen a light bulb in the socket. When bulbs age and have been used for a long time, brown spots will appear. Identifying the viability of a fluorescent bulb is somewhat more complicated. Gabrielle Black has been a professional writer, artist and designer since 2002. You will usually … We use cookies to make wikiHow great. CFLs come in a number of shapes, the most common being twin tubes, quads, triples, spirals, F type lamps, 2D lamps and circular lamps. If you really can’t stand to see another ad again, then please consider supporting our work with a contribution to wikiHow. Change out the fluorescent bulb with a new one. How to Tell If Fluorescent Bulbs Are Blown? Check if the bulb is working in another lamp; 5. Look at the end of the bulb for a dark area; if you see one, the bulb is either bad or going bad. 'FB' or 'FU' indicate that the bulb is 'bent' or 'U-shaped,' depending on the bulb manufacturer. Her theatrical designs, puppet design and construction have been featured in "Theatre Design & Technology" magazine and she has written numerous articles for various websites. If there is no reading on the multimeter, the bulbs should be replaced. Confirm that its not the circuit breaker that has tripped; 2. Well, first you need to find out if power is actually getting to the light socket. Replace the bulb with the same size bulb. Sometimes bulbs "unscrew" themselves or become rotated enough for the electricity not to flow correctly over the end pins. Bulb vs Lamp. How to Remove a Broken Light Bulb. If you’re armed with a tape measure, here’s a table to show you how to interoperate the length and diameter of your … How do you easily tell if a CFL bulb is bad? Include your email address to get a message when this question is answered. Tubes can fall out of a fixture if not properly installed. When working with electronics, make sure the power source is off to avoid electric shock. Be careful handling a fluorescent tube. Replace it with a fresh one. Light bulb manufacturers use the term “lamp” when referring to fluorescent lights. 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. 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. 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. 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. Flip the switch and wait a few seconds. 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. You must test the fluorescent bulb before considering a replacement. If there are black rings in the glass nearest the plastic body then the bulb has blown. The pieces must be sealed in a plastic bag then thrown away. For tips on replacing the starter bulb, read on! If the bulb still does not light, the gas may have leaked out and the bulb will need to be replaced. When light bulbs shatter as the failure mode then there has probably been a power surge. If the fluorescent bulb fails to come on, turn the switch off. Check your circuit breaker box and confirm that the corresponding breaker is firmly in the "on" position. Check the light bulb first to see if it has burned out. If it has a distinct odour of burnt electronics, then the bulb has blown. Last Updated: March 29, 2019 Check if the connecting pins are broken or bent; 4. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. Knowing the type of fluorescent light you will use with your ballast is a good start to your search. 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. Replace the ballast cover on the fluorescent light fixture. 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. wikiHow's. If the breaker has been tripped, push the switch entirely to the off position, and flip the switch back on. Please help us continue to provide you with our trusted how-to guides and videos for free by whitelisting wikiHow on your ad blocker. 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). When researching your fluorescent bulbs, pay attention to attributes that will help you narrow your options down. 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). Using a digital multimeter to test the bulb; 1. If your fluorescent tubes have recently fizzled out – don’t panic. How To Measure Fluorescent Tubes. If testing tube lights, be sure to test both bulbs even if only one is out. Lamp Type. Another possible code in this position is 'FC' which would mean that the bulb is a fluorescent circular bulb. Visually inspect ; 3. If they appear darkened this indicates the bulb is burned out. Step 3. 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. Only use lightbulbs that are the proper style and voltage rating for your ballast. Check for power first then the starter (if applicable) and then the bulbs. Sometimes light bulbs do shatter when they fail. By signing up you are agreeing to receive emails according to our privacy policy. And just to be thorough, you've also checked the main service panel for a tripped breaker or a blown fuse. 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. % of people told us that this article helped them. By using our site, you agree to our. With a CFL, is there any way to tell if a bulb is bad without plugging it into a socket and trying it out? If it illuminates, the suspect ballast, starter, or fixture may need to be replaced. Set your multimeter to test the resistance between the two pins Currents travel between both tubes and either could be causing the problem. If the bulb is the source of the problem, it will not light at all. 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". 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 all else fails, the ballast should be replaced. Scrub the rust and the dust at the holders; 6. Other Problems That Can Be Identified and Fixed with The Above Checks If so, replace the bulb. Make sure the power is turned off to avoid any electrical damage. Loading... Autoplay When autoplay is enabled, a suggested video will automatically play next. Hunker may earn compensation through affiliate links in this story. You can easily tell if a fluorescent bulb is burned or not. Photo 1 shows how to tell if a fluorescent bulb is bad and how to replace it. Step 1. Or in other words, the lifespan of the fluorescent bulb is over. This article has been viewed 52,369 times. Always buy quality brands if you value your time. Thanks to all authors for creating a page that has been read 52,369 times. 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