The PCOS machines in the Bayanihan Kennedytown Center did not immediately accept the ballots from two voters in precincts 15 and 16 during the resumption of the voting period at 8 a.m. Sunday.
The ballots showed no stray and ambiguous marks, one of the possible factors that could result to rejection.
The PCOS machines that malfunctioned were replaced within two hours and balloting immediately resumed thereafter.
A statement from the officials of Smartmatic TIM Corp., the supplier of the machines and the automated balloting system, said initial findings pointed to the combination of cold and humidity in HK as the culprit responsible for the malfunctioning machine.