Same problem, new solution. I tried new fuses and still the one end of each string would not light up. So I thought...Since one string has the plug end that won't light and the other has the receptical end that won't light, what if I cut the strings and put the two ends that do work together? Making sure that I connected the one wire that runs straight thru the entire string to the same on the other side and the other wire that goes into the bulbs together I now have a complete string of working lights. Forgive me but...I somehow feel like a genius right now :). And a special thank you goes out to my daddy, who passed away on Christmas Eve in 1981, for letting me tinker in the garage with him when I was a child. And to all a good nighttttttttttt!