Unfortunately there has been an issue with an older version of the HD HERO2 camera software, which would sometimes prevent the camera and BacPac from properly communicating, that then causes the LCD BacPac to not fully power on.  

We have released a newer software for the camera, which prevents this from ever happening, and also repairs communication with the BacPac if it has failed for you.  Please take a look at the LCD BacPac Black Screen with HD HERO2 camera article for instructions on how to fix your LCD BacPac.