Wii U demo console

I bought a Wii U demo unit and have a couple issues. The model for the Wii U is wis 001 and the game pad is wis 003. I used my retail Wii U power and hdmi cables and plugged gamepads coax/ smaller cable into the back of console. I have no sound on tv and my game pad won't power on. What can I do about the sound? I read in another thread that there's a separate power button for the game pad. Is this true and how does it work? Thanks