Landscape lighting rarely fails all at once. A single path light dims a little, then a fixture near the patio goes dark for a few nights before flickering back on, and by the time an entire run stops working, most homeowners have no idea whether the fix is a five-minute bulb swap or a buried wire that needs to be dug up and replaced.

That uncertainty is part of why repair costs vary so widely. According to Angi’s 2026 landscape lighting repair cost data, homeowners pay anywhere from $20 for a simple timer fix to $600 or more for extensive rewiring, with most repairs landing around $250. That range exists because “my lights aren’t working” can mean a dozen different things electrically, and guessing at the cause usually costs more in the long run than having it diagnosed correctly the first time.

Here’s what actually causes landscape lighting systems to fail, what’s safe to check yourself, and when it’s worth bringing in a professional outdoor lighting repair company like Landscape Illumination rather than troubleshooting blind.

Burned-Out Bulbs Are the Simplest Cause — But Not Always the Real One

A single dark fixture is often just a burned-out bulb, especially in older halogen systems where bulbs have a shorter lifespan and fail more predictably. Swapping it for a replacement of the same wattage and beam angle usually solves the problem in minutes.

The catch is that a bulb that keeps burning out fast, or several bulbs failing around the same time, usually points to a different underlying issue: voltage running too high for the fixture, a loose connection causing arcing, or moisture reaching the socket. Treating the bulb as the whole problem when it’s really a symptom is one of the most common reasons homeowners end up repairing the same fixture twice.

Water Intrusion Is the Most Common Reason for a Dead Circuit

Outdoor lighting connections are supposed to be sealed against moisture, but seals degrade, connectors crack, and heavy rain, irrigation overspray, or melting snow can work its way into a splice over time. Once water reaches a connection, it can create a ground fault, and if the system is on a GFCI-protected circuit, that fault trips the breaker and takes out every fixture downstream, not just the one with the bad seal.

This is why an entire section of a lighting system can go dark overnight, even though nothing was visibly damaged. The failure isn’t at the fixture that stopped working; it’s at a splice somewhere upstream that finally let moisture in.

You want your home to look its best, and having your outdoor lighting working perfectly give your the curb appeal, and keeps your house secure.

Cut, Nicked, or Rodent-Damaged Wiring

Low-voltage landscape lighting cable is typically buried only a few inches deep, which keeps installation simple but also puts it within reach of aerating equipment, edging tools, new plantings, and digging animals. A single nick in the insulation can let moisture in and cause a short months later, well after whatever damaged it is long forgotten.

Rodents are a more common culprit than most homeowners expect. Voles, squirrels, and rabbits will chew through buried cable, and the damage is often invisible until a section of the system stops working with no obvious cause. Tracing a break like this without the right equipment usually means digging up cable blindly, which is part of why wiring repairs are one of the pricier line items in Angi’s cost data.

An Undersized or Failing Transformer

The transformer steps household current down to the low voltage that landscape fixtures run on, and it’s the single point of failure for the entire system. If it stops working, everything connected to it goes dark at once, regardless of how healthy the wiring or fixtures are.

Transformers fail for a few predictable reasons: age, a blown internal fuse, water intrusion if it’s mounted somewhere exposed, or being undersized for the system in the first place. An undersized transformer that’s been quietly overloaded for years is a common discovery during a professional inspection, and it’s a case where a repair doesn’t really fix the underlying problem — the unit needs to be replaced with one properly sized for the fixture load.

Photocells and Timers Wear Out Too

If a system isn’t turning on at all, or is turning on at the wrong time, the transformer and wiring might be perfectly fine. Photocells, which sense ambient light and trigger the system at dusk, get dirty or degrade over time and can stop reading light levels accurately. Mechanical and digital timers can also fail or lose their programmed schedule after a power interruption.

These are some of the least expensive fixes in Angi’s data, often in the $20 to $60 range, but they’re frequently misdiagnosed as a bigger electrical problem simply because the symptom looks the same from the outside: lights that aren’t on when they should be.

Voltage Drop Makes the Far End of a Run Look Dim, Not Dead

Not every problem is a total failure. Voltage naturally decreases the farther it travels from the transformer, so fixtures at the end of a long cable run can appear noticeably dimmer than ones closer to the source, even though every connection is intact. Homeowners often describe this as lights “getting weaker” over time, when in reality the system was designed with a run that’s simply too long for the wire gauge carrying it.

Fixing voltage drop isn’t a matter of replacing a part. It requires rebalancing the electrical load across the system, sometimes by rerouting wiring or splitting a run across additional transformer outputs, which is a diagnostic and design problem more than a repair.

What You Can Safely Check Yourself

Before assuming the worst, a few checks are safe for most homeowners to do on their own:

• Confirm the breaker or GFCI outlet feeding the system hasn’t tripped
• Check that the transformer’s timer or photocell is set correctly and hasn’t lost its schedule
• Inspect visible bulbs for obvious burnout and swap in a matching replacement
• Look along exposed sections of cable for cuts, fraying, or wire that’s worked its way to the surface

What’s not safe, or productive, to handle yourself is opening a transformer to test internal components, digging up buried cable to search for a break without tracing equipment, or working on splices while the system is live. These are the situations where a professional diagnosis saves both time and money compared to trial-and-error repairs.

When to Call a Professional Landscape Lighting Repair Company

Some signs point clearly toward a professional repair rather than a DIY fix: an entire zone or the whole system going dark at once, fixtures that keep failing repeatedly after being replaced, visible corrosion or discoloration at connectors, or a system that’s noticeably dimmer overall than it used to be. Any of these usually means the problem is upstream of what’s visible, which is exactly the kind of issue that requires proper voltage testing to pin down.

Working with Landscape Illumination for a repair means the diagnosis is done with the same equipment and process our team uses on new installations, not guesswork. We test voltage at multiple points along a run, trace wiring to find breaks without unnecessary digging, and check transformer output against the actual fixture load before recommending a fix.

What Professional Repair Actually Looks Like

A proper repair visit starts with understanding what the system looked like when it was working, since that tells us what changed. From there, our technicians test the transformer’s output, check voltage at fixtures throughout the run to isolate where the drop-off starts, and inspect accessible connections for the corrosion or water intrusion that’s the most common root cause.

Once the actual cause is identified, whether that’s a single bad splice, a failed photocell, or a transformer that’s been undersized since installation, we fix that specific issue instead of replacing parts that were never the problem. That’s a meaningfully different approach than swapping bulbs and hoping, and it’s why professional repairs tend to actually resolve the issue rather than delay it.

For bigger jobs, call the professionals. We know how landscape lighting works, and can get the repair done for you.

Repair vs. Replace: When an Aging System Should Be Redesigned

Not every problem is worth repairing individually. If a system is more than 10 to 15 years old, was installed with halogen fixtures and undersized wiring by today’s standards, or has needed several unrelated repairs in the past couple of years, patching each new failure as it appears usually costs more over time than redesigning the system properly. This is especially true for older halogen systems, where fixtures run hotter, use more power, and fail more often than the LED fixtures used in current landscape lighting installations.

Part of a professional repair visit is an honest read on which category a system falls into. Sometimes that means a targeted fix. Other times, it means recommending a redesign that solves the recurring failures instead of billing for the same type of repair every season.

Protecting the System Once It’s Fixed

A repaired system is only as reliable as the maintenance it gets afterward. Seasonal checks for shifted fixtures, degraded seals, and exposed cable go a long way toward catching small issues before they turn into another repair call, and we’ve laid out a full seasonal routine in our outdoor lighting maintenance guide, including what to check after storms and how each season affects the system differently.

Schedule a Landscape Lighting Repair Consultation

Landscape Illumination has spent over 27 years designing, installing, and repairing outdoor lighting systems across the Midwest, and that experience is what separates an actual diagnosis from a guess. Whether it’s a single dead fixture or a system that’s been failing intermittently for months, our technicians can identify the real cause and fix it correctly the first time.

If your landscape lighting has stopped working, schedule a repair consultation with our team today.