Most likely the chain brake is engaged or the lock-off button is on. The saw won't run with the brake forward or the safety locked.
- Push the chain kickback brake handle fully back toward the rear handle. That's the run position.
- Depress the lock-off button on the top of the rear handle with your thumb. Keep it pressed.
- While holding the lock-off, squeeze the variable-speed trigger switch with your index finger.
IF THAT DIDN'T WORK: Check the battery. Make sure it's fully charged and properly seated. Align the battery ribs with the mounting slots and press down until you hear a click. A dead or loose battery is the next most common cause.
HEADS UP: Always grip the saw correctly. Left hand on the front handle, right hand on the rear handle, thumb wrapped under. A reversed grip can cause loss of control and injury.