Fluorescent Light Not Working? Try This

Fluorescent lights are awesome for the energy-saving benefits they provide and are incredibly common in workplaces the world over. But if you chose to install them in your home, they come with their own set of challenges. If your fluorescent lights are not working, DreamyHome has your back with the best, most affordable fixes possible.

The most common causes for a fluorescent light not working are your power supply, a dead tube, dead ballast, or a faulty starter.

Keep reading for all of the troubleshooting tips that you could possibly need – and how to fix the issues.

Troubleshooting: Fluorescent Light Not Working

The first step to any repair is figuring out what’s causing the problem in the first place. We’ll start with the basics and move on in time to the more involved repairs – but let’s try the easy stuff first, shall we?

As a note, before we get into things, don’t forget that you’re working with live electric circuits. Always turn the power off if you plan to handle anything with a current before doing so.

Now, let’s get to it.

Fixture Not Lighting At All

The absolute most common cause for a fluorescent light not turning on is that the tube is simply burnt out, just like any other light with a bulb.

So let’s start with checking your tubes. Theoretically, you should have a few spare tubes lying around – if not, go buy them. They’ll save you time in the long run and help loads while troubleshooting. Be sure to purchase the correct type of tube for the light fixture you have – no need to have useless lights lying around. And if you’re measuring the length of the tube yourself, don’t forget to include the pins in that measurement (this isn’t the voice of experience talking or anything… don’t ask me about it).

If you’ve already replaced the tube, it’s time to pull out the trusty multimeter and take a look at your power supply. Follow these steps:

  1. Grab your multimeter and run a voltage test on the light fixture.
    1. If it comes back as an open circuit, you aren’t getting power to the fixture.
  2. If you do have power at the fixture, the next step is to repeat the process at the switch.
  3. Barring any power issues, your next stops will be the starter and ballast, in that order. Keep reading to see how to replace them properly.
  4. If you have an open circuit reading, it’s time to call an electrician. That’s a sign that there’s something wrong with the wiring of your home – which is not something you should be messing with.

Light Flickers When On

First things first – ensure your light tube is secured snugly in the fixture. You’d be surprised how often slightly tightening the tube will fix flickering. While you’re up there, inspect the tube to see that it’s not burnt out – the ends will be blackened if it is.

The next step is to run a voltage test as we did above. Begin by testing the voltage of your light fixture, then move on to the switch. An open circuit means that there’s no power at one end, the other, or both. In this case, refer to step 4 above.

Light Hums and/or Buzzes When On

You know the sound that most people associate with fluorescent lights? That humming and buzzing sound that makes you want to pull hair out? Yeah – that’s a sign that the ballast for your light has gone out.

No need to test voltage here, if this is the problem, you’ll want to hop on down to the ballast replacement section below.

Fixes: Fluorescent Light Not Working

And now we get to the fun part – fixing the issue! Now that you’ve discovered the source of the issue, it’s time to get it solved. The two most common parts that need replacement are the starter and ballast – let’s begin with the starter. After all, it’s in the name that it goes first, right?

Starter Replacement

Let’s start with some important information. If your light fixture is from the last ~5 or so years, you don’t have a starter. The “instant-on” ballast has taken the place of starters in modern lights, meaning you’ll need to skip down to the next section.

With that out of the way, it’s actually rather easy to replace a starter. Generally, fluorescent light starters are located on the inside of the fixture, at one end of the tube. They look a bit like a D battery – large, round, with a node on the end.

All you need to do is remove it (they usually screw into place) and take it to a hardware store to find the proper replacement. Simply pop the new one into place and theoretically, you should have a functioning light.

Ballast Replacement

This is the most involved fix that you should have to do. Let’s just get right into it:

  1. As mentioned above, shut off power at the breaker to your light. You’re going to be working with electricity, meaning you don’t want to get zapped. Now you test with a touchless voltage detector to ensure the power is completely off.
  2. Remove the diffuser. This is generally attached to the sides and can be removed by putting light pressure on both ends of the tube.
  3. Remove the tubes from your light fixture. Generally you can do this by twisting them out of place.
  4. Locate the socket underneath a metal cover plate. The plate is usually secured by compression tabs, though they could use screws. Remove the cover and detach the sockets so you can reach the wires beneath. Disconnect all wires attached to your ballast, unless they’re attached by wire connectors. In this case, simply detach the wire connector.
    1. While not usually the issue, sometimes the socket can go bad. Simply take this with you when going to buy a new ballast and purchase a replacement socket if you think this could be the problem.
  5. Remove the old ballast and find a replacement. It will be easiest to bring it to the store in which you bought the light and simply ask for a replacement (though some Google sleuthing could still find a new ballast if needed).
  6. Replace the ballast and go in reverse order to put everything back where it should be. Test, and hopefully all is working perfectly again!
    1. If this hasn’t solved the problem, it’s time to call a pro.

Final Thoughts

Fluorescent lights are awesome, but if they stop working, they’re generally harder to troubleshoot. Begin by replacing the tube, as that’s often the source of the issue. If that doesn’t work, you can move on to looking at whether they hum, buzz, or flicker – that in combination with their age will tell you if it’s a faulty starter or ballast. Follow the steps above, and you’ll be able to replace any faulty parts rather easily.

If you find that replacing parts didn’t solve the problem, it’s time to call a professional. They’ll be able to thoroughly examine your home and fixture to see if the issue lies in your home’s wiring or power supply, or if it’s the fixture itself.

Related Topics To Read Next

Window Mechanism Broken? Here’s What to Do

Plug Stuck in Socket? Here’s What to Do

How To Fix A Broken Ceiling

Electric Meter Not Working? Here’s How to Troubleshoot

Dimmer Not Working? Check This Out

Light Switch Broken? Here’s Why

Door Handle Broken? Try This

How To Get a Screw Out of Your Wall

Broken Window? Here’s How to Fix It

How To Fix a Broken Glass Door

How To Fix A Broken Plug

Plug Sockets Not Working? Here’s Why

Is Your Light Bulb Out? Here Are Some Fixes

About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.