Hello.
The springs are from behind the buttons that are on the outer edge, possible the central button also. Even though the actual switch on the circuit board hold the buttons out the springs are in place to provide less wear and tear on the switch itself. Put the game back together and Inspect each control switch on the game to see if the button or toggle is loose. none of the buttons should have any slack in them, if they do these are where the springs are from.
I hope this points you in the right direction for re-assembling it correctly
Regards GM