An equipment failure that caused trains to move slowly in San Francisco’s new Central Subway on Sunday has been fixed.

The San Francisco Municipal Transportation Agency crews inspected, replaced and realigned support cables at the crossover tracks near Chinatown-Rose Pak Station that caused a misalignment of the sectionalizing breaker—an automatic switch—on the subway’s overhead power lines.

“We believe this solved the problem and restored the overhead to full service,” SFMTA spokesperson Erica Kato said.

The malfunction caused trains to travel slowly on Sunday morning. To keep the subway running, the transit agency installed a temporary cable and operated trains in only one direction. Full service was restored at 11:30 a.m.

The $2 billion extension of the T-Third light rail line soft-launched last month and operates only on weekends so staff can be trained as final touches are completed for the full opening on Jan. 7.

The mega project is four years late and some $375 million over budget by last tally. Other issues that have challenged the new transit line since it opened include party cups used as drain pipes and faulty smoke detectors that set off the fire alarm.