Repairing Faulty Mini Holiday String Lights

Pry mini-Christmas lights out of their sockets.

Miniature bulbs are a staple of many holiday decorating setups, appearing in a wide range of colors and sizes. They can also be temperamental, so when a strand goes dark, a bit of know-how can keep the display going. With some basic diagnostic steps and a handful of spare bulbs, a mini light strand can often be returned to service long before the holiday arrives.

Diagnosing Problems With Mini Holiday Lights

A common piece of advice from professionals is to test mini light strands before putting them up. Skipping that step can mean having to remove them again once you discover they no longer work after a year in storage.

Begin by connecting the strands to an outlet and inspecting every bulb. Should the entire strand stay dark, disconnect it from power. Next, push back the plastic housing around the plug to expose the fuse. When the metal filament within the fuse's glass tube shows a break, open the small sliding compartment and take the fuse out.

Obtain a replacement fuse of matching size and rating and install it in the compartment. With multiple fuses present, it may be necessary to swap them one by one until the faulty one is identified. If the fuses check out but the strand remains dark, a single defective bulb may be interrupting the whole strand.

Working With a Holiday Light Tester

Picking the bad bulb out of hundreds by eye is not realistic, which is why a Christmas tree light tester is worth keeping nearby. These low-cost devices can be invaluable for tracking down bulbs that have failed. Certain handheld models feature small openings that accept the end of a bulb, and they require the strand to be plugged in during use.

Other testers on the market locate and repair faulty bulbs by pushing electric charges through the bulb's circuit to correct internal failures. These models are operated by squeezing their triggers.

Some bulbs, however, cannot be salvaged. For a bulb that will not respond, press and hold the tester's top button while running the tip along the string until it beeps. Once the beeping ceases, unscrew the faulty bulb and put in a new one. Replacement bulbs matching your strand's specifications are easy to find for purchase.

Additional Pointers on Swapping Bulbs

What if you are diagnosing mini light bulbs while they are already on the tree? Artificial Christmas trees are built in separate sections, and on an illuminated model, each section carries its own plugs. Locate those plugs before working on the bulbs, and confirm that every connection is seated before testing the lights. Having a tree light tester within reach during assembly is a sensible precaution.

To use a tester, take the dark bulb out of the strand and fit its small socket into the opening on the tool. Squeeze the trigger twice to restore the internal shunt, then screw the bulb back into place. Work through the remaining bulbs the same way, replacing any that still fail to light. If a large number of bulbs remain dark after the sockets have been addressed, purchasing a new strand of mini holiday lights may be the better option.