Lights Stopped Working – Troubleshooting & Fix The Problem

We all take for granted how convenient it can be that we can turn on or off lights anytime we need to. But what happens when your lights stop working and you can’t figure out why? Was it the bulb that blew? Did something fall off inside of the light switch? Do we have mice eating the wires?

Hopefully, you don’t have mice eating your wires, or else you have a whole different problem. In most cases, the problem is something that you can remedy yourself without having to call an electrician.  

Chances are, your lights have stopped working because of one these four common reasons:

  1. The light fixture was unplugged.
  2. The light bulbs burnt out.
  3. The circuit breaker or GFI got tripped.
  4. The socket tab got flattened, and it’s not making contact with the light bulb.

Some other common reasons might include:

  • The light switch has stopped working.
  • The Light fixture has stopped working.
  • The wires are not connected properly.
  • The ballast needs replaced.
Safety First

Before attempting to fix any problems with your light switch or light sockets, remember to turn the breaker off first to avoid electrocuting or burning yourself. A helpful tool to invest in is a voltage tester; they are inexpensive and will alert you if there is any power still going to the light switch or electrical outlets. It’s also smart to work with rubber gloves and to make sure that you aren’t standing anywhere near a wet surface. However, do remember that it’s always a much smarter idea to consult an expert rather than try to fix electrical issues yourself.

Why Light Bulbs Burn Out

Over time, the constant surging of electricity through a lightbulb will wear down the filaments on the inside. Eventually, over time, the filaments will get thinner and more brittle, until a single surge of electricity will either cause the filaments to break, burn, or melt completely. That is why your lightbulb will suddenly go out, or make a popping sound right after flipping the switch on.

If this happens, replacing the lightbulb itself is likely the only solution that’s needed. If your lightbulb is flickering, however, the light bulb may be okay, and you may only need to tighten it in its socket to get it to stay on.

Why Would a Light Switch Suddenly Stop Working?

Light switches can go bad over time, and when that happens, the easiest solution would be to replace it since they are inexpensive.  But before you do replace the switch, you should be aware that there are other reasons why the switch might have stopped working.

No Power

A light switch could lose power if the circuit breaker has been tripped, which will prevent electricity from flowing to the switch. Circuit breakers will trip as an automatic response to wires heating up. If it’s safe to turn the power back on, you can reset the breaker, or press the reset button on your ground fault interrupter (GFI) sockets.

Short Circuits

A common reason for a light switch to stop working is for example, when a “hot” wire comes in contact with a “neutral wire,” a large amount of current will flow through the circuit and cause the circuit breaker to short out and shut itself off before something bad could happen.

Short circuits are dangerous because they have the potential to start a fire.

Loose Wires

Sometimes over time, the wires within their terminals will begin to loosen. Loose wires can cause the lights to flicker when the switch is turned on or cause the switch not to work at all. With the breaker turned off, you can go to your breaker box, remove the baseplate, and tighten up the wires in their terminals.

If the wires aren’t that loose, you can disconnect them from the switch, twist them together with pliers, and use the voltage tester to check if power is running through the wires or not. If it is, the problem is most likely not with the wires, but with the switch itself. In that case, you’ll have to have the entire light switch replaced.

Circuit Overload

If you have an old light switch or tend to keep all the lights on in your house, you might be at risk of overloading the circuit by demanding more electricity than your circuit breaker can provide. A circuit overload can lead to short circuits and blown fuses due to the excessive amount of heat all the power creates at once.

Ground Faults

Like a short circuit, a ground fault occurs when a hot wire touches the grounding wire and blows the grounding fuse. A ground fault might cause an unusual smell or a burnt socket. Unless you’re an electrician, this needs to be fixed by a professional and not tampered with on your own.

Do Light Sockets Go Bad?

Light sockets can go bad. One of the more common reasons is when a light bulb is screwed down and tightened too much, causing the contact to squish down and become flattened. If the light bulb is no longer able to connect with the contact, the light can not get power.

A flattened socket tab or damaged socket may also occur if you’ve been unknowingly using the wrong type of lightbulb for the socket in question. It is possible to raise this tab back up, but make sure that the power is off before touching it.

The socket may also be discolored to signal a problem. Discoloration may be caused by burning from faulty wiring behind the socket, but it can also be caused by collecting rust over time that prevents the bulb from connecting with the tab in the socket.

What Would Cause a Light Fixture To Stop Working?

Below are some common reasons for a light fixture to stop working.

Burnt Bulb or Socket

As mentioned previously, light bulbs and light sockets can go bad. The problem with your lighting fixture not working might be as simple as a burnt-out lightbulb or a dirty/flattened socket. Changing the bulb or socket might be required to correct the problem.

 Faulty Wiring

Like with a light switch, the wiring in a light fixture can experience a short circuit, circuit overload, or a ground fault, if the wiring is not properly connected to the light, if it’s loose, or if it is improperly protected. The wires can also end up touching the metal parts of the fixture and redirecting the electricity away from the bulb. Bad wiring within a light fixture can be a potential fire hazard or cause for electrocution, so either call an expert in to fix the wiring or get a new light fixture altogether.

Problems with an Outlet

If your light fixture plugs into an electrical outlet via a wall plug, the problem may lie within the outlet rather than the light fixture. The outlet could possess any of the wiring problems listed above, or the circuit may be prone to tripping due to the outlet being in areas with moisture, such as a bathroom or on the wall of a kitchen counter.

These circuits can get reset if plugged into a GFI socket, but if the light in your fixture doesn’t turn on when plugged into the outlet, it is most likely a problem with the bulb, the light socket, or the wiring in the walls.

How Do I Know If My Light Socket is Working?

If you have changed your light bulb and you have ruled out that it’s not a bad bulb, and the circuit breaker wasn’t tripped, the culprit might be the light socket not working. Here are some simple tips that you can follow to check the socket.

Continuity Test

A continuity test is a basic test that you can perform when troubleshooting any light fixture, and it will help determine whether the electrical circuit is good or bad, continuous or broken. First, you want to check to see if there is a voltage available at the lighting outlet box or not. For this, you can use either a digital multimeter or a non-contact voltage tester to check for AC voltage. The non-contact voltage tester is recommended for homeowners since it does not require you to touch a probe on live wires carrying a current. Instead, all you have to do is bring the noncontact voltage tester close to the lighting fixture with the light switch on.

Troubleshooting Incandescent Fixtures

First, start by turning off the circuit breaker at the service panel, so there is no power going to the lighting fixture. Next, carefully remove the light fixture from the outlet box and double-check the circuit again using a voltage tester to make sure that you have turned off the right circuit breaker (video below showing how to test for this).

Here  is a quick video showing you how to test that there is no power:

Once you have confirmed that there is no power going to the fixture, you can disconnect the fixture wires so you can then check the continuity. Use a digital multimeter set to the ohms function (Ω), check the white fixture wire for continuity by placing a probe to the bare metal on the white wire, and another probe to the metal shell inside the light socket. Test multiple spots all around the metal shell. If there is continuity, the multimeter will display “0.000” on the screen. If the socket is bad, the screen on the multimeter will display “O.L.”

Next, check the continuity between the black fixture wire and the brass part at the bottom of the light socket. Again, the screen on the multimeter will display “0.000” if its good, and “O.L.” if it’s bad. If you get any bad reading during the tests, you know there is a problem with the light socket and it needs to be changed.

If the continuity test shows that the light socket is OK, but the light still doesn’t work using a new light bulb, then what is most likely happening is that the brass contact at the bottom of the light socket got flattened and the light bulb is not able to come into contact with it. With the circuit breaker still turn off, the brass plate will need to be pried away from the base of the socket.

How Do You Fix a Light Socket?

Sometimes a light socket can go bad, and rather than replacing the entire light fixture, you can replace the socket instead. It’s a fair, easy job, but before you attempt to change it, you need to turn off the circuit breaker at the service panel. It’s always wise to double-check with either a digital multimeter voltage tester or a non-contact voltage tester to confirm that you have completely shut off the power before going near any wiring.

Here is a very helpful video that will help explain how to change a light socket.

What Are The Signs of a Bad Ballast?

When people see a fluorescent bulb flickering, their first thought is normally that the bulb will soon need to be replaced; however, it may not be a bad light bulb at all, but rather, the ballast on the fixture needs to be repaired or replaced.

Below are some commons signs that the ballast on your fixture is not working correctly.


A strobing or flickering light is the most obvious sign of a bad ballast. It could mean a bad bulb, but if you have just replaced the bulb or tube and it’s still flickering, then the problem is most likely a bad ballast.

Buzzing/Humming Sounds

If you are hearing any buzzing or humming sounds coming from the fixture, it is a sign that the ballast is about to go. Noticing any sounds is a good time to test the ballast and make any repairs necessary.

Different Levels of Light

Bulbs can change colors throughout their lifespan, especially in tubes, but if you are noticing dark areas or just overall inconsistent lighting, that could be a sign of a bad ballast.

Starting Delay

A light that is slow to come on is another common sign of a bad ballast. Keep an eye on the lights and see if they take longer then usual to reach its full brightness.

Low Lighting Output

Lastly, low output lighting or dimmer than normal lighting is a sign of a bad ballast. This could also mean the bulb has reached its lifespan, but it’s important to check the ballast first before replacing it.

Some less common causes are:

  • Burn marks on the casing
  • Casings that look swollen
  • Leaking oil (this applies to a magnetic ballast)

What Causes a Bad Ballast?

Ballasts will typically last about 20 years if under the proper conditions. Knowing what causes a ballast to go bad is important in keeping light fixtures in good working order to maximize how many years you can get out of it.

The most common reason’s for a ballast to fail is due to heat and moisture. Extreme temperature changes can affect the ballast, whether it be too hot or too cold. However, heat and condensation (high humidity) will cause corrosion, which can damage the ballast.

The good news is, some fixtures offer a UL rating that is better suited for damp/wet locations. When placing your fixture, take note of where it is getting mounted and make sure that it can withstand temperature changes as well as high humidity levels.

Repairing a broken ballast is typically quick and easy if you are comfortable working with light fixtures. The whole procedure should take you around 10 minutes to complete. There are several videos and tutorials online that can easily guide you through the process. If you are unsure or not comfortable with the repairs, make sure to contact a professional for help.

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