@ADC100 

Hi, 
You can try the following steps and see if they help.

  1. Remove the SD card from the camera if there is one. 
  2. Power the camera with the original power adapter and cord.
  3. Wait for a while, press the power button on the camera for three seconds, and check if you can turn it on. 
  4. If not, press and hold the reset button on the camera for 10 seconds to perform a factory reset. Then, check whether the camera's system LED will turn on.
  5. If the camera still can't be turned on, you can contact your retailer or the technical support team to check if the camera is under warranty.

Best Regards

  @Annecutler 

Hi, 
You can refer to the instructions below to set up the Tapo C402.
How to Set Up Your Tapo Camera Using the Tapo App
 

If you fail to set up the camera, please refer to the following instructions for troubleshooting. If the problem remains, it's recommended to contact the technical support team for assistance.
Fail to configure Tapo Camera

Best Regards