The HD HERO Original camera will make a clicking noise if the LCD BacPac is attached if you haven't first updated your HD HERO Original camera's software.
If you do not see the LCO/LCF options in your camera's settings menu, then you'll need to update your camera's software. Please remove the LCD BacPac and battery. Reinsert the battery only. Next, please update your HD HERO Original camera's software.
Once you've completed the camera software update, you should be able to use your camera with the LCD BacPac.