San Diego Airport Authority spokeswoman Cheryl Brown says the electricity was back on in Terminal 1 just after 3:30 a.m. Sunday.
A high-voltage transformer blew on the terminal's roof Saturday evening.
Lights went out, but came back on when an emergency generator kicked in. However, electricity remained out in the Southwest Airlines Co. area of the terminal.
The outage shut down computers, jet ways and the baggage delivery system. Brown says workers had to push stairs by hand to the doors of arriving aircraft so passengers could exit. Luggage was moved by hand instead of carousel.
The cause of the transformer failure is being investigated.