I'm a bit new to circuitry in general, but I'm pretty confused about how this string operates — specifically the fact that there three wires connected to the board with the microprocessor (which controls the blink patterns). Why 3 wires?
I'm guessing the lights don't all turn on/off at the same time, there's really two or three strings woven together.
Also, could someone explain to me why when I remove the board between the power source (three AAA batteries) and the lights, and just connect the lights to the power source directly — nothing works?
Three AAA batteries is only enough to light up two LEDs. The board must have a voltage booster circuit on it to raise the battery voltage to whatever's needed for the LED strings (something like a "joule thief").