Alienware start button

Hi all,

I have my alienware aurora r4 since July and when it was delivered I  had to push the button in about a quarter of an inch to get the pc to start

it is not a normal round push button and I had to either push in the center or use two fingers to push on each sides, a couple of days ago it stayed in

but still works with just  a little pressure it  turns the pc on (or manually off) without actually moving .

What is the what it is supposed to work with a definite movement or just pressure?

Thanks

Claude