This looks like any other SOT-23 device:
But the markings are turning up little. Pin 1 (bottom-left) has something connected to pin 3 (top.) Pin 2 is N/C. So this seems like a zener, except there are four of these (two each on two malfunctioning boards) and they all measure about the same, as 18-25Ω resistors. Is that a common failure mode for SMT zeners with no visible damage, and what was this supposed to be?