Often, a burnt light bulb will look darker. The burnt filament may leave a charred dark spotinside the light bulb. It may even make the whole bulb much darker. Its filament will be broken, and even a loose piece may be in the bulb.Click to see full answer. In respect to this, how can you tell if a Christmas light is blown?With the plug in hand, slide the door marked “Open” in the direction pointed by the arrow. Remove the two fuses, and inspect them by looking at them up against a bright background (such as the sky). If the fuse is good, you should see an unbroken strand of wire running between the two metal contacts.One may also ask, how do you remove a broken lightbulb from the socket? First, make sure the light switch is turned off. Use gloves, eye protection and a pair of pliers to break away any remaining glass. Cut the potato in half, firmly press it against the socket and begin twisting counter-clockwise. The potato should grip the base of the bulb and turn it while the socket remains still. Correspondingly, why do only half Christmas lights work? A loose bulb, broken socket or frayed wire is sometimes all it takes for the strand to malfunction. After taking down the lights, plug them in before storing them, to make sure they still work.Do LED Christmas lights burn out?LED Christmas lights use light-emitting diodes, rather than filament to produce light. This new technology makes LED lights more efficient, durable, and longer-lasting than fluorescent incandescent lights. They don’t burn out, like other bulbs; and they also don’t get hot to the touch, so they’re a lot safer, too.