Chosen Solution
I have been working with a volunteer team to put up thousands of LED Christmas lights and incandescent lights. The light strings that are working at the end of the season are coiled up and placed in totes and placed in a storage shed. When we have pulled them out and started stringing them we discovered quite a few strings have only half the string working. I have read where the LEDs are steel and can rust and can create an open circuit. I believe that open circuits don’t damage anything else. But, a burned out LED will likely be shorted increasing the current in the circuit. That would be the same as removing the socket from the circuit and soldering the resulting leads together. Now…Current in a circuit is the same throughout the circuit. So…if you removed or had several LEDs burn out and short, than this circuit would have higher current flow…and if this string was the first in a daisy linked chain of strings…would this endanger the entire length of this chain? Some of our chains are 20 strings long and some are 40 strings long. Supposedly this was per manufacturer. So would the higher current flow of the first string raise the current for the entire chain endangering and shortening the life of all those strings?
Although im not exactly sure, it very well could be possible. Depending on how many are out depends on how much current. So if in lets say daisy chained strands equaling to 500 lights and 9 are out, it isnt going to do much harm, but if 200 are out, some major damage could be done to the other lights. But for the relatively short time they are in use, it should be fine. They should last for a few years yet before maor damage will occur.
I don’t think we have enough information to deduce what would happen here when you have a short or burnt LED. There are a few different ways the string could be wired…
Lets say you have three colors and you have them in a linear order (Y - G - R) over and over again down the chain. So the string is wired so you could blink the different colors independently. Then you would have three intertwined strands and the plug would house the blink controller. Then we get into the construction of the bulbs them selves. In many of the newer incandescent bulbs there is a special wire that shorts across the given bulb so the string is still working.
This is an interesting question. You have several sets of LED lights connected together, one set is missing half of the lights which is the question that having that many LEDs out would stress the rest of the strands. As long as the current for the whole chain is below the burn out threshold of the LEDs then it should be good although it would be smart to monitor the strands in case more LEDs burn out. But, when in doubt you should replace the defective set or remove it. The leads on the LEDs are copper with tin/lead solder or silver solder, the leads can oxidize and that could be the problem. You can try to remove the defective LEDs and use a pencil eraser to polish the leads to get rid of the corrosion.
