I have too many pre-lit garlands with lights not working. I've replaced fuses, checked each mini light, and get a positive for electrical in each of these, but the lights still do not work.
Sometimes the replacement bulbs arent compatible with the sockets they are screwed in. Contact customer service for the right bulbs to buy.
Pre-lit trees and garland uses a special light bulb that has a small fuse in it. You'll need to find the right light bulb to use in order to make this work again. This is hard because every light has to be tested and changed until you find the one that is burned up.