Place the toothbrush handle on the charger. Does the battery indicator blink or do you hear a beep? If yes, your toothbrush needs to be charged. 
When charging, make sure that you use the original charger that came with your Philips Sonicare Toothbrush. Charging components are not interchangeable. If you have a DiamondClean handle, see the matrix below to ensure that you are using a compatible charger. 

Handle Name	DiamondClean	DiamondClean Smart	DiamondClean 9000
Code on bottom of handle	HX93, HX934, HX935, HX936, HX937	HX992, HX993	HX991
Code on bottom of charger base	HX9100	Type: CBA1001, CBA2001, CBA3001	Type: CBA5001, CBA4001

Also make sure that you plug your toothbrush into a working electrical socket to charge it. 
Charging times may vary per toothbrush model. See your user manual for more details on charging.

Toothpaste residue can build up in the small gap around the power button. This might cause the power button to get stuck and not function properly. Clean the power button and the area around it with a damp cloth to make sure it is free of debris.  We recommend removing the brush head after each use and rinsing the brush head and the handle under water to remove residue.
 

If you are using a smart toothbrush, note that it gets software updates when connected to the app. This happens through firmware updates. Some of these updates improve charging capability.

Follow these steps to check if you have the latest firmware installed on your toothbrush handle:

Update (or download) the latest version of the Philips Sonicare app from the App Store or Google Play.
Open the Philips Sonicare app
Tap on the menu icon in the top left corner
Go to 'My Products'
Select your toothbrush
Select 'Handle update' to see if any updates are available
If you have updates available, please update the firmware of your handle by following the instructions from the Philips Sonicare app.

If none of these tips solved your issue then please contact us or try our troubleshoot assistant for further support.