I've tried doing this quest twice now and both times I've gotten stuck at this part. I've read that you need to go through all four teleporters before this can work, and I've gone through them at least two dozen times only to never have the teleporters shut off and enable this step. I have most certainly put all of the clocks down, and each teleporter is definitely active: Cafeteria behind the electric wall, Cell Block key room, Cellar teleporter and Reception buildable teleporter. I even went through Observation teleporter a few times for good measure, still no luck. Has anyone happened upon a solution?

I've been playing with the All-Around Enhancement add-on, so next time I attempt this quest I'll do it without and see if that makes a difference. If anyone has any input on that, that would also be swell.