Before you reset your toothbrush
If you’re having issues with your toothbrush, wherever possible, make sure it has a decent amount of charge before resetting it. A low charge level can lead to unexpected operating problems that won’t resolve with a reset.
Resetting the toothbrush
Don’t be alarmed if the brush vibrates during the procedure. It’s normal.
Press and hold the power button for about 10 seconds. The toothbrush will shut down. After pressing the power button again, the Smile light will then blink quickly in red, meaning that the toothbrush has been successfully reset.
You might see the Smile light blinking in blue while the toothbrush restarts. This means your toothbrush is being paired via Bluetooth.