[hubbard]

I opened a new box of 200 Christmas mini lights (not LED) and 50 in the middle do not work. There are no missing or broken bulbs. I checked the 50 unlit bulbs to make sure they were seated tightly and they are. Do I need to check the ones that work? I know this is not a big problem in the scheme of things but I already put them up on a large outdoor tree. Would this indicate some sort of individual bulb problem or a fuse problem or a wire problem? I can reach the 50 unlit bulbs and the plug as fortunately they are on the lower part of the tree. Thanks if you have any suggestions.

 

[Msradell]

Long strings like that are normally broken up into several shorter strings internally. More than likely one of the bulbs in the section that's not working when out and thus took out the whole section. You can buy a voltage detector quite easily and if you sniff around each bulb that's not working with one of those it will illuminate when it gets to the bulb that's blown...

 

[jimn]

A 200 light string is actually 4 50 light strings wired together. Each bulb contains a shunt that allows the section to work if one bulb burns out. I often find these shunts fail at an alarming rate. If this was new, return it.

 

[twinboston]

As was said above, a 200 light strand is 4 50-light strands. The 50 light segments are wired in series, but the four sets are parallel; hence why 50 go out at a time, rather than the whole strand.

It's not a fuse problem, since the other sets of 50 are lit. If you've confirmed that all 50 bulbs are good, you're likely dealing with one of three things:

1. A broken wire
2. A bad socket
3. Multiple loose/improperly seated bulbs

Get a LightKeeper Pro, use the shunt repair feature, and if that still doesn't work, use the voltage detector to narrow where the break in the current is.