how to figure out which christmas light is bad

Ah, the age-old question of figuring out which Christmas light is bad. Let me see if I can help. You know how when one light goes out, the whole strand stops working? Well, the best way to find out which one is the culprit is to start with the first light on the strand and work your way down. You can do this by carefully removing each light bulb one by one and testing them with a tester or a multimeter. Once you've found the bad bulb, simply replace it with a new one and voila!