Up2 Board doesn't boot, no LED lights up, no screen

Hi all,

I just bought an Up2 board for my final year project and trying to use it yesterday. I'm using an adapter rating 5V,6A to power up my Up2 board but it does not seems working at all. No LEDs light up and nothing shown when I connect it to a screen.

I had tried to loosen the screws for heat sink and press reset button for 10 sec, but it stays the same.

Anyone know what should I do? Thank for your time.