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Fix a light that will not turn on

We'll check power, the bulb, the switch, and the fixture to get your light working—or tell you when to call an electrician.

Troubleshooting · Home maintenance
5–20 min
What you'll need
  • Known-good bulb (from another fixture)
  • Screwdriver (for switch cover and fixture)
  • Multimeter (optional; for continuity tests)
  • Replacement bulb, switch, or fixture (if tests show a fault)
Step 1 of 10

Quick triage — pick your path

Quick triage — pick your path

Choose the option that matches what you see. You can jump straight to that section.

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Steps

Goal: Confirm the symptom, rule out power and the bulb, then isolate the switch or fixture.

  • Flip the switch. Check whether only this fixture is out or all lights in the room are out.
  • Good: Light does not turn on—proceed to Check power.
  • Bad: Light flickers or works sometimes—different fault; check the bulb connection or switch.

Check power

Goal: Rule out a tripped circuit breaker or GFCI before touching the bulb or fixture.

  • Go to the electrical panel. Confirm the breaker for the light circuit has not tripped. Reset it if tripped.
  • Check for a GFCI outlet in the same room, bathroom, or garage. A tripped GFCI can cut power to downstream lights. Press Reset and test the light.
  • Good: Breaker on and GFCI not tripped. Proceed to Check the bulb.
  • Bad: Breaker keeps tripping when you reset it—there may be a short. Call an electrician.

Check the bulb

Goal: Rule out a burned-out, loose, or wrong-type bulb.

  • Turn off the switch. Remove the bulb. Check that it is seated firmly. Look for a dark spot or broken filament (incandescent) or blackened base (CFL). If the light is on a dimmer, confirm the bulb is dimmable.
  • Install a bulb you know works from another fixture. Turn on the switch.
  • Good: Known-good bulb lights—the original bulb was the fault. Replace with a new bulb of the correct type.
  • Bad: Known-good bulb does not light—the fault is the switch or fixture. Proceed to Check the switch and fixture.

Check the switch and fixture

Goal: Isolate a faulty switch or socket.

  • With the switch on, listen for a click. A loose or non-clicking switch may be faulty. If you have a multimeter, turn off power at the breaker, remove the switch cover, and test for continuity when the switch is on.
  • Turn off power. Remove the bulb and inspect the socket. Check the center contact—the small tab at the bottom. If flattened, gently pry it up with a small screwdriver. Look for corrosion or discoloration.
  • Good: Switch and socket look good—the fault may be in the wiring. Call an electrician.
  • Bad: Switch has no continuity or socket is corroded—replace the switch or fixture, or call an electrician if not comfortable.

Smart bulb path

Goal: Get a smart bulb responding again.

  • Confirm the switch is on—smart bulbs need power to the fixture to work.
  • Open the smart home app. Check that the bulb is connected and not turned off in the app. Try turning it on from the app.
  • If the bulb is unresponsive, power-cycle: turn the switch off for 10 seconds, then on. Check the manufacturer instructions for a reset procedure if needed.
  • Good: Bulb responds in the app or after power-cycle. The light turns on.
  • Bad: Bulb still unresponsive—try a known-good standard bulb to confirm the fixture works; if it does, the smart bulb may need replacement.

When to get help

Call an electrician if:

  • You have checked the bulb, power, switch, and fixture and the light still will not turn on.
  • The switch or fixture feels hot or sparks when you use it.
  • The wiring looks damaged or corroded.
  • You are not comfortable working with electrical wiring.

Verification

  • The light turns on when you flip the switch.
  • No flickering, buzzing, or sparks.
  • The bulb is the correct type (dimmable if on a dimmer) and properly seated.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify the light does not turn on—single fixture vs whole room.
  2. Power Check the circuit breaker and any GFCI outlet that feeds the light.
  3. Bulb Check the bulb is snug, not burned out, and the correct type. Try a known-good bulb.
  4. Switch and fixture Check the switch for continuity and the socket for corrosion or a flattened center tab.
  5. Call a pro Call an electrician if fixes did not work, wiring is damaged, or you are not comfortable.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Whether one fixture or all lights in the room are out
  • Whether a known-good bulb works in the socket
  • Switch continuity test result (if performed)
  • Socket condition (corrosion, center tab)
  • Steps already tried

Does the light not turn on at all?

Flip the switch. If only this fixture is out, the fault is likely the bulb, switch, or fixture. If all lights in the room are out, the fault is likely power.

Flip the switch. Check if this is the only dead light or if the whole room is dark. Good: light does not turn on—proceed. Bad: light flickers or turns on sometimes—different fault; check the bulb or switch connection.

Yes No (flickers or intermittent)

You can change your answer later.

Is power on? (breaker and GFCI)

A tripped circuit breaker or GFCI can cut power to the light.

Check the circuit breaker for the light—reset if tripped. Check for a GFCI outlet in the same room, bathroom, or garage. Press Reset on the GFCI. Good: breaker on and GFCI not tripped. Bad: breaker keeps tripping—call an electrician.

Yes No

You can change your answer later.

Reset breaker or GFCI and test

Reset the circuit breaker or press Reset on the GFCI. Test the light. If the breaker trips again immediately, there is a short—call an electrician. If the light works after reset, the fault was power.

Done

Does a known-good bulb work in the socket?

The most common cause of a dead light is a burned-out or loose bulb.

Turn off the switch. Remove the bulb and install a bulb you know works from another fixture. Turn on the switch. Good: known-good bulb lights—original bulb was the fault; replace with a new bulb. Bad: known-good bulb does not light—fault is switch or fixture.

Yes No

You can change your answer later.

Light working

The light turns on. Replace the original bulb with a new one of the correct type and wattage. Confirm the bulb is dimmable if the light is on a dimmer.

Done

Does the switch have continuity when on?

A faulty switch will not complete the circuit. Test with a multimeter or replace the switch.

Turn off power at the breaker. Remove the switch cover and test the switch for continuity with a multimeter when toggled on. Good: switch has continuity when on—check the fixture and socket. Bad: switch has no continuity when on—replace the switch (or call an electrician if not comfortable).

Yes No

You can change your answer later.

Replace the switch and test

Turn off power at the breaker. Replace the switch with a matching type (single-pole, three-way, etc.). Restore power and test. If the light still does not work, the fault is in the fixture or wiring—call an electrician.

Done

Is the socket clean and the center contact making contact?

A corroded socket or flattened center contact can prevent the bulb from making contact.

Turn off power. Remove the bulb and inspect the socket. Check the center contact—the small tab at the bottom. If flattened, gently pry it up. Good: socket clean and tab up—fault may be wiring; call an electrician. Bad: socket corroded or damaged—replace the fixture or call an electrician.

Yes (still dead) No (corroded/damaged)

You can change your answer later.

Replace fixture or call a pro

If the socket is corroded or damaged, the fixture may need replacement. If you are comfortable with electrical work, turn off power and replace the fixture. Otherwise, call an electrician.

Done

Call an electrician

Call an electrician if: the light still will not turn on after checking the bulb, power, switch, and fixture; the switch or fixture feels hot or sparks; the wiring looks damaged; or you are not comfortable working with electrical wiring.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a light not turn on?
Common causes: a burned-out or loose bulb, a tripped circuit breaker or GFCI, a faulty switch, or a bad socket or fixture. Smart bulbs may need a reset or app check. Check the bulb first—it is the most common fix.
Should I check the bulb or the switch first?
Check the bulb first. Turn off the switch, remove the bulb, and try a known-good bulb in the same socket. If the known-good bulb works, the original bulb was the fault. If it still does not work, check power and the switch.
When should I call an electrician for a light that will not turn on?
Call an electrician if you have checked the bulb, power, and switch and it still will not turn on, the switch or fixture feels hot or sparks, the wiring looks damaged, or you are not comfortable working with electrical wiring.

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