Sonicare Toothbrush Turns On By Itself. Getting ready to remove solder. Once a mode is selected, the toothbrush works for a specific time period and then turns off automatically.

To change this, press the mode/intensity button (power button in some instances) to change the setting. Follow these steps to check if you have the latest firmware installed on your toothbrush handle: Here is an overview of possible modes and their timings: