GENEVA (Reuters) - The giant sub-atomic particle collider built to reproduce Big Bang conditions is set to restart this autumn, the European Organization for Nuclear Research (CERN) said on Friday. Scientists believe they have figured out how to prevent a repeat of the problems that caused the 10 billion Swiss franc ($9.2 billion) Large Hadron Collider to be shut down just nine days after it was switched on last September, CERN expert Steve Myers said in a statement. The machine the largest and most complex ever made overheated because of a faulty splice in the super-conducting cable connecting two cooling magnets, according to Myers. There are 10,000 splices around the underground colliders 27-km (17-mile) ring, which smashes particles together at a temperature of just above absolute zero to recreate the conditions believed to have been present at the beginning of the universe 13.7 billion years ago. CERN has put back the start date several times, and most recently said the collider would restart in September. Many new tests have been developed, Myers said. That has given us a wealth of information about the LHC splices, and confidence that we will be in good shape for running this year. Among the repairs and modifications made to the collider which are thought to cost up to $30 million are a system to respond to any heating up of its core, several added pressure relief valves, improved vacuum technology, and stronger anchors connecting its magnets to the floor. All of this contributes to preparing the machine for a long and safe operational lifetime, CERN said.