To find the hidden HOY-BV2500 Generator, choose the "Eliminate Leos Klein" mission. Work your way through the corridoors with the bombs. There will be a circular room and a door on your left. In this door is a hallway with 2 doors that your radar will not pick up. The door on your right is empty. Further down the hallway is a door on your left.(coordinates: X-000564, Y-000256, Z-000537). Enter this door and on the floor to your right is the hidden generator part.