If your brush head does not move, please consider two solutions.

1. Please reinstall the brush head as shown in your toothbrush user manual.

2. Please charge your Philips Sonicare toothbrush for 24 hours. 

If this problem persists, please refer to the warranty chapter in your toothbrush user manual. User Manuals are available on the web on the Support page under your products HX model number.  Click Here for Support page