December 7, 20160 found this helpful
all lights need power and ground, if you show that you have current flowing but no illumination then you have a bulb out at or near the end preventing the circuit to be complete. try unplugging that string and turn the plug around to reverse the current. you should now see there is no current. now go spend $20.00 on a light keeper pro. you can follow the current to the point it ends, thats the problem bulb.