Philips sonic toothbrush no longer vibrates head

A vibration transducing part inside the device is loose. Philips installed a screw into the vibrating mass but did not apply adhesive, causing the screw to come loose over time.

Symptoms:

The device turns on and vibration engine starts, but the brush does not vibrate. The brush/shaft might feel loose inside the housing.

Solution:

Remove bottom cover. This is glued, you might need to apply mild heat or cut it open and replace the cover later.

The device's active components can be slid out of the housing after loosening two retention clips. Remove the white charging coil bracket for easier access to the clips.

Bottom of the toothbrush with the cover and the small white bracket around the charging coil removed. Retention clips are on the left and right about 2cm deep

The insides of the device removed from its housing. The loose screw can be seen near the top of the device on the right

Tighten the philips head screw towards the top of the device. Test if vibration has been fixed.

Vibrating part of the sonic toothbrush which has come loose due to the unsecured screw

The copper wire around the top is an NFC coil to detect the age of the brush head. Remove the coil to disable brush replacement warnings.

Reattach the coil bracket and reinsert the assembly into the housing and close the bottom with the housing part or fill with silicone or glue.