MANILA, Philippines - Laboratory tests for 72 of more than 30,000 Precinct Count Optical Scan (PCOS) machines are ongoing and going well, a Commission on Elections (Comelec) official said Saturday.

Commissioner Gregorio Larrazabal, head of the poll automation steering committee, on Friday visited the warehouse in Cabuyao, Laguna where the machines are stored for laboratory tests.

"I'm happier now than last week," Larrazabal said, noting that no problem has been found in any of the machines so far.

Last week, some 600 machines reportedly rejected ballots cast, which the Comelec official denied.

He said only one machine rejected ballots, which were poorly shaded. He said the machine just had to be "re-calibrated" to accept ballots.

The ballots have selection ovals placed beside each candidate’s names. Each circle should be shaded at least 50 percent by the voter so that machines will be able to count their votes, Larrazabal said.

"That's why we do the tests," he said. "If you see something you don't like, you can still change it."

Done to ensure the automated polls will go smoothly, laboratory tests simulate the steps of the entire voting process -- from the casting of ballots, transmission of votes to a server up to the canvassing of votes -- in an indoor setting.

The Comelec has banned media coverage for the tests citing security concerns.

After the tests, machines will undergo field testing on January 27 where the entire voting process will be replicated outdoors.

Voting centers will be set up in Metro Manila and some provinces where votes will be cast and then transmitted to a Comelec central server.

Only members of the Comelec's advisory council, technical evaluation committee, and the Department of Science and Technology will be involved in the field test, said Larrazabal.

The Comelec has also scheduled a nationwide mock elections on February 6. Registered voters in selected areas will be asked to participate in the mock polls, which Larrazabal calls the ultimate test for the machines.