Stuck at finale

[FadedShadow]

I've completed everything on Shay's end but when I get Vella to the deck and try to trigger the death ray, she says "It should have worked before, Alex did you disable the deathray?"

I tried triggering the deathray once before consulting a walkthrough and now it won't work.

[Northern Distortion]

Alex turns the power back off. You must return to the power switch and turn it on.