The issue had threatened the space shuttle Endeavour's construction mission and astronauts were thrilled to hear the robot was powered up.
With the successful power bypass, NASA is keeping on track Saturday night's spacewalk to hook the robot's 11-foot arms to its torso.
The 200 million-dollar robot is designed to be a helper for astronauts conducting spacewalks.
NASA is promising a full investigation to determine how and why the design flaw happened.
