24v brushless DC Driver Pinout
I don't see anywhere near enough devices on that board for it to be anything like a servo controller.

I would guess you have a simple electronic commutator, with no provisions for any other control (except perhaps PWM speed control). I wouldn't be surprised if it couldn't even reverse.

The board looks to be just two layer, and all the parts are nice and big, so it shouldn't be too much trouble to map out the traces. That should get you a rough schematic.