Just making sure, but according to the wiki, I quote:
The terminal on the mainframe contains some notes the player has
probably already seen on previous terminals in the building, and an
option Configure Power Grid. Selecting it reveals 5 options:
5 Full region (emergency output level): This solution overloads the plant, which prevents Archimedes I from being activated (see further
notes). This gains no reputation with any faction, but Ignacio Rivas
will still give the player some rewards.
If the player has chosen to activate the Archimedes I defense system,
and has chosen option 5 (overload) for the power grid, horns will
blare and a warning will play about the imminent weapon test, but
shortly thereafter everything grinds to a halt. If the player is
trusted by Ignacio Rivas, they can now go talk to him to receive
awards. Otherwise the quest ends.
You did not do this, right?
Edit: Further down that page:
- pc The Archimedes I sequence may not play out even though activated at the mainframe.
You could have run into that.