Hi.
This 3 leg component (looks like any other smd transistors) is found within an old HP 930C printer from 2001, more specific it is located at the internal power supply board, hi voltage side.
I haven't done any attempt to draw the schematic, doing so may help identify it's real type.
However, I'm interrested in being able to work out what kind of component it is based on it's printed number - if possible.
So far, google haven't being of any help - only wasted my time redirecting to click-bait websites (I mean, those that list up millions of part numbers at once just so someone get to follow its links).
PCB board:
ASTEC MODEL : AA20550
HP PART NO : C6426-60081
white label underneath: B266816R1 0103