Not sure - likely smacked against something, I never babied it. I couldn’t find a repairer for less than the price of a new one.

I wore a version of this as my only watch for over 10 years. It finally got retired when the crystal got cracked kayaking and I couldn’t get anyone to repair it. Even so, it still worked, and I bet if I put it in the sun now it would start up again. Awesome travel watch with the dual time, alarms etc.