A report in the Telegraph says that it was switched on to great fanfare on September 10, but had to be turned back off nine days later because the cooling mechanism broke. It takes weeks to rechill the machine to 'superconducting' temperatures - allowing it to fire protons around a 17 mile loop of tunnels, causing them to crash into one another at close to light speed and break into even tinier particles.
"It is very probable that there was a connection that wasn't good," said Lyn Evans, project leader of the 17-mile LHC, buried deep under Swiss soil at CERN, the European Nuclear Research Organisation.
Evans said that he did not think a single fault in 10,000 connections was bad, but "it cost dearly".
Although the problem can be fixed within two months, there will not be time to restart the collider before the winter, when high electricity prices make it too expensive to run.
"It was a hard blow for us," Evans said. "But that's life," he added.