Symptoms
- Trigger does nothing when squeezed
- No sound or movement at all
- Worked fine on the last use
- Power light, if present, is off
Likely causes
- CommonSafety trigger lock not disengagedMost miter saws require pressing a lock-off button before the trigger works.
- CommonBlade guard interlock not fully releasedSome saws won't start unless the lower guard is in the correct resting position.
- CommonDead outlet or tripped breaker/GFCIShop outlets and garage GFCIs trip easily and cut power silently.
- PossibleDamaged power cordA cut or pinched cord can lose continuity even without visible damage.
- PossibleWorn carbon brushes or internal switch failureThese wear parts eventually stop making reliable contact.
What to do
- Confirm the safety lock-off switch is fully pressed before pulling the trigger.
- Lower the saw head fully and check that the blade guard is seated correctly, since some models interlock with it.
- Test the outlet with another tool or a phone charger, and check the breaker or GFCI reset button.
- Inspect the power cord along its length for cuts, kinks, or looseness at the plug.
- Try a different outlet on a different circuit if the first one seems fine but the saw still doesn't run.
- If everything above checks out, stop using the saw and have the internal switch or brushes inspected.
Tools and parts
- Tested outlet
- Screwdriver
- Multimeter (optional)
Carbon brush setSearch: “miter saw carbon brushes replacement”
When to call a pro
If the outlet, cord, and lock switch are all fine and the saw still won't start, a tool repair shop should check the internal switch and brushes.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.