🔎 What’s in This Guide
🔧 What You’ll Need Before You Start
You don’t need a fancy tool bench to do this job, but you’ll want to be ready. Here’s what to gather:
- A voltage tester (or multimeter)
- Phillips and flat-head screwdrivers
- Wire strippers (just in case)
- New circuit board (OEM or compatible with your fixture)
- Optional: Soldering iron (only if wires are soldered, not plugged)
- Safety gear: gloves and safety glasses
- Ladder or step stool if your light is mounted high
💡 What Does the Circuit Board Actually Do?
Think of the circuit board as the brain of your emergency light. It tells the unit when to charge the battery, when to switch on during a power outage, and when to shut things down. If it fails, nothing else works right.
Here are some signs that the circuit board might be bad:
- The light stays off, even when you hit the test button
- The charging indicator doesn’t light up—or blinks erratically
- The unit gets warm or smells like something’s burning
- You see blackened spots or corrosion on the board itself
🔍 Step 1: Make Sure You Get the Right Replacement
Before ordering a new board, flip open the fixture and check for a label. Most emergency lights will list the model number and sometimes the exact board part number. If you can’t find one:
- Take a photo of the old board and search online by image
- Call the manufacturer’s support line
- Match it by voltage (6V, 12V, or 24V) and battery type
You can often find universal boards that work with multiple models, but make sure:
- It matches your input voltage (usually 120V or 277V)
- The connectors are similar (plug-in vs screw terminal)
- It supports the same battery chemistry (NiCd, NiMH, or SLA)
💪 Step 2: Replace the Circuit Board (Step by Step)
1. Kill the Power
Start at your electrical panel and turn off the breaker that powers the light. Double-check with a tester—don’t assume it’s off! Then, unplug the battery inside the unit.
2. Open the Fixture
Use your screwdriver to remove the plastic lens or cover. Inside, you’ll see the battery, the LED heads, and the board itself.
3. Take Photos of Everything
Before unplugging anything, snap a few good pictures of the wiring. Label the wires with masking tape if you need to. This will save your sanity when reconnecting things.
4. Remove the Old Board
Unscrew the board from the housing. Some boards slide into plastic clips, while others use screws. Gently unplug any wire connectors. If it’s soldered in place, you’ll need a soldering iron to remove it.
5. Drop in the New Board
Line up the new board just like the old one. Reattach the screws or clip it into place. Then, reconnect the wires exactly how they were before. Use your reference photos!
6. Secure Everything
Neaten the wires with zip ties or clips so they don’t shift around. If you had to cut or strip anything, use proper connectors or heat-shrink tubing.
7. Close It Up and Test
Pop the cover back on and flip the breaker to restore power. You should see the charging LED come on. Press the test button—if the lights turn on for 30+ seconds, you’re golden.
🤔 What If It Still Doesn’t Work?
- No lights during test: Check battery connection and polarity
- No charging LED: Make sure AC power is actually reaching the unit
- Buzzing or heat: Disconnect immediately—wrong board or miswiring
💵 How Much Does a Replacement Board Cost?
Most replacement boards run between $15 and $45, depending on the brand. Universal boards cost a bit less, while OEM replacements may be pricier but fit exactly.
You can buy them online, from an electrical supply store, or directly from the manufacturer. Pro tip: If you're replacing several, buying in bulk can save you 10–20%.
🔄 Should I Replace the Whole Light Instead?
Sometimes, the board isn’t the only thing failing. Here’s when it makes more sense to replace the whole fixture:
| Keep the Light | Replace the Whole Thing |
|---|---|
| Housing is in good shape | Cracked or yellowing plastic |
| LED heads still work | One or more heads are dead |
| Battery still holds a charge | Battery is old or swollen |
| You want to save money | You want a newer, sleeker fixture |
🚀 While You’re In There…
This might be a good time to upgrade your emergency light. Modern boards come with helpful features like:
- Self-testing diagnostics: Does the monthly test for you
- Universal voltage: Works on 120V or 277V input
- Remote head capable: Power additional lights from one board
✅ Final Thoughts
Replacing a circuit board might sound technical, but it’s often no harder than changing a thermostat or a light switch. With the right tools and a bit of patience, you can fix your emergency light and keep your space code-compliant and safe.
If the board doesn’t fix it—or the fixture’s seen better days—consider upgrading entirely. Check out our full lineup of LED Emergency Lights or shop Exit Signs with Battery Backup to find reliable, modern alternatives.