Finish game

I got to the very last part of placing all the objects where they belong but can't seem to find a place for the fingerprint scanner. Any suggestions? I think I have placed it everywhere on the board but it doesn't do a thing.

On the spot where the key pad is there is a small area on the left with some wire/circuit board showing. That's the spot.
Now I have to find out how to open the darn vault.

i'd like to know how to finish the game. on the last thing , placing your found objects on the different places-like where?

Th fingerprint goes on the scanner.

This is the solution to last puzzle:
quarter goes in slot on slot machine, cup in scale, red lever by scanner, king with other cards, slot arm on slot machine, fingerprint on scanner pad, clock on wall in round wooden frame, and hourglass under clock in metal circle.

Then, plug in cord on slot machine, drop quarter in slot, pull slot arm, hit hourglass with hammer, clock on hourglass, it will tilt and fill cup, which will push red lever to on postion, and drag fingerprint from evidence caard over to scanner pad, and enter win line from slot machine into scanner pad.

This should unlock safe.