How to fix half a string of Christmas lights?

There is a product you can buy at wal-mart - most any store that kinda looks like a space gun that

checks and finds prooblems with a string of lights.

Works great and cuts down the time it takes to find burned out bulbs in a string of lights or loose connections.-

This may not work for everyone but... The first thing I usually do is sort of shake the whole strand. If they flicker when I do that, then it's probably a loose bulb. Next I make sure each bulb in the strand is tightly in it's socket, and I try to hold them up to a light to try to see if any look burned out. Sometimes there may be a bulb missing. Sometimes it is just the fuse too.

Good luck :)

Cheap Christmas lights have that problem. Here's a tool that you can use to find the problem and fix it: http://www.christmasworld.com/installation-accesso...

Also it might help to have better quality lights with a warranty: http://www.christmasworld.com/christmas-lights

Happy Decorating!