Troubleshooting My Philips Sonicare toothbrush won't switch on? If the handle of your Philips Sonicare electric toothbrush will not switch on, there might be a simple solution. Resolve it yourself with these easy tips. Tips and tricks: Ensure the correct button is being pushed (power button vs. mode button). The mode button will not turn the handle on. Reinstall the brush head as it is shown in your toothbrush users manual If there is not a brush head on the handle it may not be easily heard. Try placing a brush head on the handle and turning it on. Place the handle in the charger and charge for 24 hours before turning it back on If the handle still does not switch on, please contact customer service.