Additionally, Nelson recommends the LightKeeper Pro, a tool that diagnoses and fixes Christmas string lights, which is available in both incandescent and LED versions.

To help offset the price difference, Home Depot is offering $3 to $5 coupons to customers who trade in their old Christmas light strings (either working or non-working).

Holdouts to the LED Christmas light revolution are finding it harder to get replacement bulbs for well-loved incandescent strings that have been passed on within families.