Hey oscar, couldn't you test all of the light sensors by doing a multimeter test aka: placing the positive prode on the left positive screw in, and the negative on the black, then having a 5v somewhere coming in, and just put something black in there to see if it's changing at all, because if it is working, shouldn't it send a shorted signal for the time its working *just like normal joystick pcbs or microswitches*. Or do I have my logic off somewhat....
-Luke