how to find a bad bulb on led christmas lights

If one of your LED Christmas lights isn't working, the first step is to find the bad bulb. To do this, you'll need to inspect each individual bulb for any signs of damage or discoloration. If you see a discolored bulb, it's likely that bulb that needs to be replaced. If you don't see any visible signs of damage, try unscrewing each bulb from the strand and testing it individually on another string of lights. If the bulb lights up on the other string, then the original strand is the problem.