I have a Christmas light problem.

The problem is that I have a 150 set of Twin light blinking Icicles.
Some of the lights/strands aren't lighting and I can't figure out why.

There are 15 "icicles" (strands) on the whole set. Icicles # 1,4,7,10,
& 13 blink first. Then icicles # 2,5,8,11, & 14 blink second. Finally,
icicles, # 3,6,9,12, & 15 blink last; these are the ones that aren't
lighting up. There are a total of 50 bulbs in these and I've tested
every one of them - they all work.

The first light in the first and second strand each have a blinker
light in it. The third strand didn't have one as it was in the very
last light on the whole set. So I moved the blinker into the first
light/bulb of the third string, but they still won't light up.

Any ideas on why they won't light up if all the bulbs are ok? I don't
want to throw them out as I can't find any stores that carry these. I'm
sure they do somewhere but not around here. Also, these were purchased
very cheap at a yard sale and as far as I can see, they had never been
opened. So I have no idea if they're just faulty or if something else
is going on.