LED Light Not Working but Has Power? 6 Fixes to Try

Why Is Your LED Light Not Working When It Has Power?

An LED light that has power but stays dark almost always comes down to one of five faults: a failed bulb, an incompatible dimmer, a dead LED driver, a loose neutral, or a false reading called ghost voltage. LEDs draw so little current that a fault an old incandescent bulb would shrug off will leave them completely dark.

Most are fixable in minutes with no special tools. Work through the six checks below in order, cheapest first.

One rule before you start. Turn off the breaker for that circuit, not just the wall switch. The cable feeding the fixture carries a full 120 volts whether the light is on or off.

Does the Fixture Actually Have Power?

A beeping non-contact tester does not prove a fixture has usable power. Pen-style testers react to induced voltage on nearby wires, so they chirp happily on a conductor that cannot deliver any real current.

Electricians call this ghost voltage (or phantom voltage), and it is the most common reason a homeowner is sure a dead fixture “has power” when it does not.

Real power means about 120 volts measured between hot and neutral with a multimeter, ideally one with a low-impedance (LoZ) setting. LoZ mode loads the circuit slightly, so ghost voltage collapses to near zero while real voltage holds steady.

No multimeter? The safest test is simpler. Screw a known-good bulb into the fixture, or plug a working lamp into an outlet on the same circuit. A bulb that lights is proof. A beeping pen is not.

Two safety limits are worth respecting:

• Swapping bulbs with the switch off is safe for anyone.
• Probing wires inside an open fixture or switch box means working near exposed live parts. If that is outside your comfort zone, stop at the bulb swap.

If the whole circuit is dead rather than one light, look upstream first. A tripped or failing breaker gives the same symptom, and those causes live in why a circuit breaker keeps tripping.

What Are the 6 Fixes to Try?

1. Swap in a Known-Good Bulb

Start with the cheapest possibility. Turn the switch off, let the bulb cool, and reseat it firmly, since LED bulbs are light enough to back out of a socket over time, especially on a ceiling fan that vibrates.

Then install an LED you have already seen work elsewhere. If it lights, the old one simply failed. Dead LED bulbs are far more common than the packaging suggests, and the reason is almost always heat, covered further down.

2. Clean the Socket and Reset the Contact Tab

At the bottom of every screw-base socket sits a small brass tab. Repeated bulb changes flatten it and corrosion builds up, until it no longer makes solid contact.

With the breaker off, gently pry the center tab up about an eighth of an inch with a wooden or plastic tool, then clean the threads. This tiny repair revives a surprising number of “dead” fixtures.

3. Match the Dimmer to the Bulb

Dimmer mismatch is the single most common cause of an LED that flickers, buzzes, glows faintly, or refuses to turn on. Older dimmers were built for incandescent bulbs and typically need a minimum load of about 25 to 40 watts to fire properly.

A single 9 watt LED sits far below that, so the dimmer never reaches its stable range. Two things have to be true at once: the bulb must be marked dimmable, and the dimmer must be rated for LED loads.

Here is what each dimmer type does on an LED:

• TRIAC (leading edge), the standard incandescent dimmer, is built for incandescent and halogen. On an LED it flickers, drops out below 10 to 20 percent, or stays dark.
• ELV (trailing edge), sold as electronic low voltage, is made for dimmable LED fixtures and drivers. It usually needs a neutral in the switch box, and it runs smooth when matched.
• CL or LED-rated universal dimmers are built for screw-in dimmable LED and CFL bulbs. Expect few problems if your bulb is on the maker’s compatibility list.
• 0-10V is commercial dimming for panels, troffers, and shop lights. It needs separate low-voltage control wires and is rare in homes.

When you buy a replacement, look for “CL,” “LED,” or “ELV” on the package and check the maker’s compatibility list for your exact bulb. If the light is switched from two spots, a miswired traveler can mimic every symptom above, so it helps to know how 2-way and 3-way switches are wired before swapping parts.

4. Check for a Loose Neutral

An incandescent bulb will glow through a marginal connection. An LED often will not. A loose wire nut, a backstabbed connection that has worked loose, or an oxidized neutral can leave the hot leg reading “live” on a tester while the circuit cannot actually pass current.

A broken neutral is the classic case where a fixture looks powered but stays dark, because the return path to the panel is gone.

With the breaker off and verified dead, open the fixture box and the switch box, confirm every wire nut is tight, and make sure each conductor is fully seated. Pay special attention to the white neutral bundle.

If connections keep loosening, or you find the same fault at several fixtures, that points to a larger problem with the home’s wiring rather than one bad splice.

5. Test or Replace the LED Driver

Many modern flush mounts, recessed wafer lights, and under-cabinet strips are integrated fixtures with no replaceable bulb. Each one holds a driver, a small power supply that converts 120 volt AC into the low-voltage DC the diodes need. Drivers fail more often than the diodes do.

The telltale signs of a dying driver:

• Dead despite a confirmed 120 volt supply.
• Flashes on for a moment, then cuts out.
• Only part of a panel lights.
• Works cool, then quits as it warms up.
• Hums, buzzes, or smells hot.

The same logic hits older fluorescent troffers converted with ballast-compatible LED tubes: the tube still leans on the old ballast, and a dead ballast means a dark tube even with power at the fixture.

This is where DIY usually stops. A replacement driver has to match the original’s output type (constant current or constant voltage), voltage, and wattage, and a wrong match can cook the new fixture. If you have reached this point, call (877) 473-1995 and we will connect you with a local electrician in San Angelo who can match the part and confirm the fault before you spend on the wrong one.

6. Stop Smart Switch Leakage Current

An LED that glows faintly or blinks when it is supposed to be off usually points at the switch, not the bulb. Smart switches and dimmers wired without a neutral keep their electronics alive by trickling a small current, typically 2 to 10 milliamps, through the bulb itself. Incandescent bulbs never showed it. LEDs do.

Fixes, from simplest to most thorough: use a slightly higher wattage LED, install a small bypass capacitor (sold as a minimum load capacitor) across the fixture leads, or replace the switch with a model wired to a true neutral.

Do LED Bulbs Really Last 25,000 Hours?

Only in the conditions the rating assumes: open air at about 77 degrees Fahrenheit. Ratings of 15,000 to 25,000 hours come from that testing, and the box says nothing about a sealed globe, an enclosed porch fixture, or a can light under a poorly vented attic.

Heat is the enemy, and it kills the driver electronics in the base of the bulb long before the diodes dim. In an enclosed fixture, a bulb without the right rating can fail in a few thousand hours.

West Texas makes this worse. San Angelo attics and enclosed exterior fixtures spend long summer stretches far above the temperature those ratings assume, so early failures are common here. For any globe, jar, or sealed can, buy bulbs marked enclosed fixture rated. They cost a little more and last dramatically longer.

What Does Repair or Replacement Cost in 2026?

If troubleshooting ends at a fixture that needs replacing, national cost data as of 2026 lands in a few clear ranges.

Labor to replace an existing fixture typically runs $50 to $300. A new fixture installed, part plus labor, usually totals $100 to $650. Electricians charge roughly $50 to $130 per hour, and jobs that need new wiring or a new box add $200 to $500.

Simple like-for-like swaps on existing wiring land at the low end. Heavy fixtures, tall ceilings, and anything that means running new cable push the price up.

When Should You Call an Electrician?

Call a licensed electrician when the bulb, the socket, and the dimmer are all ruled out and the light still will not work. Call immediately if you find scorch marks, a warm switch plate, a buzzing switch, or a burning smell.

Those signs point to a failing connection, which is a real fire risk. The right move is to shut off that breaker and get emergency electrical help rather than keep experimenting.

In Texas, electrical work is regulated by the Texas Department of Licensing and Regulation under Occupations Code Chapter 1305. Homeowners who own and live in their house are exempt for work on that home, but permits through the City of San Angelo still apply to anything beyond a like-for-like swap, and rules change, so confirm current requirements with the local permit office before opening walls.

For diagnosis, a licensed electrician traces the fault with proper test equipment instead of replacing parts one at a time, which is exactly what an electrical repair and troubleshooting visit is for.

Get the Lights Back On

If you have worked through the six fixes and that LED is still dark, the remaining causes live inside boxes and behind walls where guesswork gets expensive fast.

Call (877) 473-1995 and we will connect you with a local electrician in San Angelo who can find the real fault and fix it right. No pressure and no obligation.