Early last Saturday morning, an unexplained power glitch resulted in a loss of power to some International Space Station systems that are operated by one of eight power channels for the complex (4B channel). The crew was never in any danger, and the affected systems were repowered in a short period of time by one of the other station’s power channels (4A).
As of Monday morning, all impacted station systems are operating normally while flight controllers in Mission Control review data to try to assess the cause of the problem and a forward plan of remedial action.
-NASA