Story: Putting up my mom's Christmas tree today, we had it all lit up, bright nice 7.5" tree. About 10 or so minutes later the bottom strand goes out so we spend a good couple of minutes checking the fuses and making sure the bulbs are fine (it's wired in parallel, so why would that matter?). Replace the fuse with a known good fuse etc etc, no joy.
I finally got a hold of a DVOM and find out the working strands have around 55volts but the dead strand has .15 volts at the first light socket. I didn't think jumping from the outlet to the first light socket would be a smart idea so I skipped that.
So is there any reason the electricity won't flow through that light strand? I've verified the plugs are fine.