Electrical & LightingBuildingWrench repair guide

Exit Sign Not Lit: Facility Troubleshooting Checklist

An unlit exit sign may have lost normal power, failed LEDs, a bad battery or charger, or internal electronics trouble. Document and correct it promptly because it is part of the egress system.

Safe first checksSkill: Beginner-friendlyFormat: Diagnose → Fix → Test
Safety boundary: This guide stops before energized wiring or panel work. Use qualified electrical personnel for internal diagnosis.
Source Control Load
Find the boundary of the problem before replacing parts.

Likely causes

Do not jump straight to the most expensive possibility. These are the common places to start:

  • Lost normal power
  • Failed led module
  • Battery failure
  • Charger failure
  • Internal electronics fault
Possible causeHow to checkRoutine first move
Lost normal powerCheck external power or charge indicatorsReplace approved lamp or battery if field-serviceable
Failed led moduleUse built-in test button if providedReplace listed sign unit if appropriate
Battery failureCompare nearby signsRetest normal and emergency operation
Charger failureRecord location and failure modeReplace approved lamp or battery if field-serviceable
Internal electronics faultInspect for heat or damageReplace listed sign unit if appropriate

Tools and preparation

Bring these

  • Flashlight
  • Camera
  • Known-good compatible lamp or plug-in tester when appropriate
  • Manufacturer instructions

Before touching anything

  • Confirm the exact location and complaint.
  • Photograph labels, settings, fault codes, and the original condition.
  • Determine whether the failure affects one item or several nearby items.
  • Know how to safely isolate the system if the task requires it.

Step-by-step checks

Check external power or charge indicators

Work through this check deliberately and record what you find before moving to the next one.

Use built-in test button if provided

Work through this check deliberately and record what you find before moving to the next one.

Compare nearby signs

Work through this check deliberately and record what you find before moving to the next one.

Record location and failure mode

Work through this check deliberately and record what you find before moving to the next one.

Inspect for heat or damage

Work through this check deliberately and record what you find before moving to the next one.

Why this order worksThese checks move from the easiest, lowest-risk causes toward issues that require more specialized service. If you find the problem early, stop there, correct it, and test before doing anything else.

Routine fixes that make sense here

Test the repair more than once. Run several cycles, use the fixture normally, or observe the equipment long enough to prove the symptom is gone. One lucky cycle is not a diagnosis.

Common mistakes

  1. Replacing parts before proving the failure.
  2. Changing several settings or components at once.
  3. Failing to photograph the original condition.
  4. Ignoring whether nearby equipment has the same symptom.
  5. Crossing into electrical, refrigerant, life-safety, structural, or plumbing work beyond training.

When to stop and hand it off

Bring in qualified help when:
  • Required egress marking is lost
  • Circuit problem affects multiple signs
  • Internal wiring fault exists
  • Housing is overheated or damaged

Frequently asked questions

What should I check first?

Start by deciding whether the problem is local to one fixture or piece of equipment. Then begin with the simplest safe observation: check external power or charge indicators.

What is the most common mistake?

Replacing parts before proving the failure. BuildingWrench recommends documenting the symptom, changing one thing at a time, and testing after each change.

When should maintenance stop?

Stop when the repair crosses your training or site-safety boundary. In this case, one clear handoff point is: required egress marking is lost.

What should I document?

Record the exact location, model or asset tag, what the equipment was doing, what you checked, what you changed, and whether the fix held through repeated testing.

Related BuildingWrench guides

Leave the next technician better information. Record what you found, what you changed, the part number if anything was replaced, and whether the repair held.

BuildingWrench provides general educational information for commercial-facility maintenance. Manufacturer instructions, applicable codes, site procedures, and required trade qualifications always take priority.

← Back to Electrical & Lighting