If your camera is not powering on, there could be a fault with the camera, battery, SD card, or there could be a loose connection somewhere. We have some tips for you to try that should clear up the issue for you.
Remove any BacPac accessories, the battery, and SD card from the camera. Reinsert the battery only. Press the power button. If the camera powers on, your camera was frozen and you should be good to go now.
If your camera doesn't power on, remove/reinsert the battery and charge the camera via a USB charger or your computer. Don't attempt to power on the camera while it's charging. You should see the red LED light on the front of the camera. Once it goes off, disconnect the camera from USB and power it on. If it powers on, your battery was dead and just needed be charged.
If your camera doesn't power on after charging and it's a HERO3, take a look at the back red LED. If it's dimly lit, remove/reinsert the battery and try to power on the camera. You may need to do this up to 10 times before the camera powers on.
If you're unable to get your camera to power on, you can contact GoPro Customer Support by using the "Contact Us" form.