Home Button Replaced but does not register the press

Hi

I have ordered a replacement Home Button for my 5th Gen iPod Touch and managed to open up the unit and replaced it. But it is still not responding when I press on the home button and the only option I can manage to get the home button to function is to remove the button itself and use a small point to press on the middle of the actual switch. I can feel the click as i do that but not with the Home button on top. Does this mean that switch itself, the middle raised part, is not elevated high enough for the home button to press down on or is there some smaller piece that should be on top of the switch that is lost? Appreciate any insights.

Will