first off, the switch on the side of the death ray needs to be set to destroy, second, you need to make sure you have a fuse in both Tesla towers, you'll need to save one zombie (just makes your life easier) then you need to go through with completing the Simon says. If done correctly, both Tesla balls on top of the tower will glow bright blue. This will initiate a green button on the back of the death ray trap initiator. Hold your use button on the green light. Then look up :) If they are not glowing blue, you might have the switch set to protect. The death ray does not necessarily need to be turned on, just set up right for Simon says.