Help me remember the story about a flight controller....

I remember watching a TV special on a NASA rocket launch where a
warning light came on shortly after take-off. It would normally call
for an abort, but a flight controller, or engineer (I can't remember),
remembered seeing an anomaly in the simulator that generated the same
warning. He quickly responded for the astronaut to cycle a set of
switches (or something like that), and that made the warning go away,
and saved the mission.

Does anyone remember this story? Who the flight controller's name
was? What switches they were?

Thanks in advance,
Joe