Marks Jewelers clock and watch repairman Alan Truong works on reassembling a piece at his bench. Truong, 49, says he has been at it fixing watches for 35 years since learning as a young man in Saigon City, Vietnam.

When time stands still, Alan Truong restarts it. He’s worked with watches and clocks for more than 35 years, the last 19 spent at Marks Jewelers, 817 Mass.

His passion for fixing things started as a child in Saigon City, Vietnam.

“We were very poor in Vietnam, so we tried to fix things because we couldn’t afford to buy something new when things broke down,” he says.

“I’d fix anything I could get my hands on, including furniture and clocks. I felt happy when I fixed things and made them useful again.”

He lived in a three-story building with several watch repair shops, and he spent hours watching clock and watch repairers at work. His fascination grew and, at 15, it became his full-time job.

Truong’s older brother Mac, who had escaped from Vietnam in 1978, and made his way to Lawrence via Indonesia and California, sponsored his younger brother to come to the U.S.

“I left Vietnam in June 1991, spent some days in Thailand, then came to Lawrence,” he says.

“My uncle (Vinh Chieu) worked as a translator for the U.S. Embassy in Saigon, then came to Lawrence and worked for Farmland. When I arrived here he told me about a job at Marks. I started working here three weeks after leaving Vietnam.”

He still fixes many things, including antique typewriters, sewing machines, jewelry and jewelry boxes, but his passion remains with clocks and watches.

“You need a good eye and gentle hands as well as skills to fix watches and clocks,” he says.

“Some old mechanisms are very delicate, and if you hold them even a little bit too hard you can break the wheels or pivots. You must go very, very gently.”

He says it’s easier to fix clocks because of the larger mechanisms.

“It takes lots of patience to work with smaller watches. You have to be very, very careful not to break them,” he says.

“Sometimes I get a watch repaired 99 percent, but it isn’t quite right, then I have to start all over again. Sometimes I have to study the part very carefully and then build a completely new one to fit in with the spring and the rest of the mechanism.”

He’s been very successful, and his reputation extends well beyond Lawrence.

“People often come to me as a last resort,” he says.

“They’ve had their watches and clocks fixed by others, but they still don’t work right or stop working. I fix them like new, and they are very surprised. People wave to me in the street and say, ‘Hey you fixed my watch (or clock), and it’s still working after all these years.’ That feels good.”

Truong says he’s glad people still value older things and want to preserve them.

“People value old things that have been part of their family for a long time,” he says.

“I don’t do this work just for money. I do it because it makes me happy to fix things and make customers happy. I’m very lucky to live in Lawrence with such friendly people and very good bosses.”