All 40km of the North East Line (NEL) tunnel have been inspected and no abnormalities were found, said SBS transit.
According to its statement, the inspection checks of the remaining 17 kilometres of the NEL track was completed after train service hours on Saturday morning.
Previously, it only inspected 23 kilometres of the track on Friday. It lasted four hours because the checks were thorough and intensive.
SBS Transit said it will continue to monitor the system closely.
Train service at the NEL was disrupted for about 11 hours on Thursday after engineers had to fix snapped power cables and electrical insulation problems.
Some 90,000 commuters were affected by the lengthy breakdown between Dhoby Ghaut and HarbourFront MRT stations.