Anat Arbhabhirama, director of the Bangkok Mass Transit System (BTS), said the malfunction forced train drivers to switch from automatic to manual drive mode in order to stop trains at Siam and On Nut.
Trains had to approach stations slowly, meaning it took about 10 minutes instead of the usual three to stop at each station.
The computerised system was reset and a normal service resumed on the skytrain from 7.45am, Mr Anat said.
Passengers faced long queues at BTS stations and trains were jam-packed. (Photos by Pattarachai Prechapanich)