The 200-year-old Presbytere on Jackson Square has reopened its doors more than six weeks after a minor fire damaged its air-conditioning and electrical systems and forced the museum to close.

The fire, which broke out April 3 in a mechanical room in the building that is part of the Louisiana State Museum, had the potential to wreak havoc, given the structure’s lack of a sprinkler system.

But New Orleans firefighters arrived swiftly and had the fire under control 17 minutes after it started, preventing a destructive blaze like the one that struck the nearby Cabildo in 1988.

Officials initially blamed the fire on a malfunctioning compressor in one of the building’s air-conditioning units, but they said Thursday that the state Office of Risk Management still is investigating the cause.

Crews fixed the air-conditioning system in order to get the Presbytere open again. Officials said they estimate the repairs and cleanup will end up costing less than $500,000.

While the fire did not damage any museum artifacts or displays, it did cause what officials described as light smoke damage to some surfaces. Long-term repairs also are expected to include some sort of remediation for the asbestos in damaged areas of the building.

The opening comes in time for the upcoming Memorial Day weekend, which is usually a busy one for the Presbytere, said Lt. Gov. Billy Nungesser, who oversees the state Department of Culture, Recreation and Tourism.

“We encourage everyone to come by and show their support,” Nungesser said.

The Presbytere was built on the site of the former residence, or presbytere, of the Capuchin monks. Built between 1791 and 1813, the building was used for commercial purposes until 1834, when it became a courthouse. In 1911, it became part of the Louisiana State Museum.

Its two permanent exhibits deal with two contrasting sides of Louisiana’s history and culture: Carnival and Hurricane Katrina. The building was designated a National Historic Landmark in 1970.

Neither the Presbytere nor its sister building, the Cabildo, was constructed with a fire-suppression system. The threat of a devastating fire has loomed over both structures for years, a threat realized in 1988 when a welder’s torch set off the fire that destroyed the Cabildo’s third floor and damaged other areas.

It took nearly six years and $8 million to restore the Cabildo, install a suppression system and make other fire safety improvements. But no such system was installed in the Presbytere,

That building has only smoke detectors and fire extinguishers, museum spokesman Marvin McGraw said. The $500,000 in repairs will not pay for a fire-suppression system, he said.

The fire-sparked overhaul is separate from $2.6 million in planned external renovations to the Presbytere and Cabildo, work scheduled for completion in August.

The Presbytere is open from 10 a.m. to 4:30 p.m. Tuesdays through Sundays.

Follow Jessica Williams on Twitter, @jwilliamsNOLA.