My Sonicare toothbrush doesn't vibrate as much or isn't so powerful.
First, make sure that your toothbrush is fully charged.
Did you purchase your toothbrush within the last 60 days? If so, your Easystart feature may still be activated. The Easystart feature gently increases power over the first 14 brushings to ease you into the Sonicare brushing experience. If Easystart is activated, your brush may not seem to be as powerful as expected.
The Easystart feature on your toothbrush may have been activated. To determine whether it has, place the handle in a plugged charger base and press the on/off button firmly. If you hear one beep, the Easystart feature has been deactivated. When you use the brush in this condition the brush will be working at its full power level. If you hear two beeps the Easystart feature has been activated, and you will feel less power.
If your toothbrush has more than one mode of operation, you may have activated a different mode with a different brushing action. For brushes with dual speed settings, the dual speed button may be at the reduced speed setting.
Old, worn brush heads can also seem to be less effective or powerful in their brushing action. If your brush head has been in use for more than 3 months, it should be replaced with a new one.