Christmas Light Question

[slowrev]

I'm not frustrated, nor am I going to spend $$ on "good" lights. There has to be a simple explaination as to why that one socket keeps blowing bulbs.

As for how Christmas light strings work, I have a pretty good handle on that...

All the bulbs in a section are wired in series.
All the bulbs have a shunt inside them.
If the filimant blows, the shunt lets voltage through.
If half your lights are out, you probably have TWO sections.
One of the bulbs probably has a bad shunt.
Finding the bad bulb can be a problem.
A product like the Light Keeper Pro can find and repair bad shunts without having to hunt for the bad bulb. It sends high voltage down the line and snaps the shunt back on. Then you just look for the bad bulb and replace it.

However, I know where the bad buld is. I just can't get any bulb to work in that socket.

the little mini series type bulbs have different operating voltages. A 100 light string will have a much lower voltage bulb than one from a 35 light string. If you put the 100 light blub in the 35 light string it will blow.

 

[chucko]

cut out the offending scocket and splice in the good part

 

[ronjhall]

I just picked up a Lightkeep Pro at Lowes for $8.50 about 20 minutes ago. Everything Christmas related is on 50% clearance. I'll let you know how it works tonight.

You must have alerted the whole TBN network. They were sold out at the local Lowe's.

 

[KubotaSteve]

After messing with those stupid lights in the freezing cold a couple years ago, I've been transitioning over to the C-9 bulbs and the rope lights. My wife has one of those pre-lit Christmas trees that rotate. She told me a section of lights were out. After she showed me, I turned the tree on until it rotated to where the unlit lights were back against the wall and turned the rotating thing off and said problem fixed .
I love decorating outside for Christmas but I hate dealing with those little bulbs.

 

[mwechtal]

O.K. I have tens of strings of 100 mini lights. You know, just like everybody else's. Nothing special. One socket on one string blows a bulb as soon as power is applied. I can't figure it out. I've disassembled the socket, looked real close, etc... what causes this? Any thoughts? I'm using the replacement bulbs that come with the sets, so that shouldn't be the problem.

MossRoad,
Maybe the bulbs they gave you are the wrong ones. You could tell with a multi-meter. Measure the resistance of a known good bulb, then one of the replacements.

Otherwise, I'd bet that you have several bulbs burnt out and shunted in that string. When they shunt, they have less resistance than a good bulb. This causes all the bulbs in the string to see a bit more voltage. You'd probably have to run the lights at a reduced voltage to find the bad ones. I'd use a Variac (variable voltage transformer) to run the string, but you probably don't have one.

Mike

 

[MossRoad]

The new Lowes on Ireland road had about two dozen left this morning.

 

[MossRoad]

The new Lowes on Ireland road had about two dozen left this morning.

That's in South Bend, Indiana, for those of you that are going to make the drive!

 

[Dusty]

MossRoad..... by this time a week from this Thursday you won't care, and will have another year to fix the problems.

 

[MossRoad]

MossRoad..... by this time a week from this Thursday you won't care, and will have another year to fix the problems.

Whadda you mean? I leave them up year round. They decorate the cars that are on blocks in my front yard. I sit on my porch recliner and watch them as I burn the trash in the barrel every evening.

 

[3RRL]

Well,
After reading this thread and downloading that Light Keeper Pro video, I jumped in the truck and went to Lowe's. Guess what? My Lowe's has never heard of it. I asked around and they told me to look in the seasonal Christmas section and there was nothing there either. Bummer! I live in Southern California, so is it just a back East thing?

 

[ronjhall]

Well,
After reading this thread and downloading that Light Keeper Pro video, I jumped in the truck and went to Lowe's. Guess what? My Lowe's has never heard of it. I asked around and they told me to look in the seasonal Christmas section and there was nothing there either. Bummer! I live in Southern California, so is it just a back East thing?

Golfgar4 says he got his at a Ace Hardware in Havasu City. I guess that is east of you.

 

[RobS]

That's in South Bend, Indiana, for those of you that are going to make the drive!

The one in Mishawaka has one less as of about 2:00 this afternoon. And the Menards near there has about 300 sq ft less laminate flooring. Guess what I'll be doing this week!?!

I handed the light tester to my 12 year old son who will attack the problem spots... after scouts.

 

[BobRip]

If many of the bulbs had the filaments open then the shunt kicks in and the remaining bulbs get higher voltage. The higher voltages causes the new bulb to burn out.

Another scenario is that the replacement bulb is a different current (probably lower) than the existing bulbs and as such is subjected to too much current when intalled. Does any of this make sense?

 

[MossRoad]

Yeah!!!! It works!

First, the problem with one socket that blows bulbs on that one string....

I have tens of these sets of lights. I have the original boxes that they came in. I have all the spares for these sets in those original boxes.... all of the spares in all of the boxes blow when put in my sets! I moved one light over from a different socket on the string and it works. I measured resistance on the spares and from lights on the sets. They are different. The ones that blow have a lower resistance than the ones that are in the sets. Therefore, I think all of the spares are for 35 light strings and not 100 light (50 per section) strings. Factory bad. Yikes!!! I ended up sacrificing one of these strings for spare bulbs.

Second, I have dozens of old strings that do not work, or only half of the string works. I replaced them over the years with new strings, but did not chuck them, as "Some day I'm gonna fix those things!"

Well, today is that day. The Light Keeper Pro actually works! I pulled a bulb from a dead string, stuck the empty socket into the Light Keeper Pro and pulled the trigger. Nothing happened. The directions said to pull the trigger up to 20 times. So I started clicking away. After 5 clicks about a third of the lights came on! A couple more clicks and more came on. 15 clicks or so clicks and all but about 5 came on. I started pulling those bulbs and testing them in the Light Keeper Pro's tester. They were bad. I replaced them and the entire string is good!!! So I'll let you all know how things go later in the evening.

 

[tallyho8]

I would take a working bulb out of the socket next to the one that is burned out and try it in the bad socket. This is just in case that your replacement bulbs are accidently the wrong voltage. If this fails to work, check the voltage in the bad socket with a voltmeter and the voltage in a good socket and see if they are the same. If the voltage is the same, then we go to the next step.....

I guess we don't have to go to the next step now. MERRY CHRISTMAS

 

[MossRoad]

I guess we don't have to go to the next step now. MERRY CHRISTMAS

It worked good. Thanks!

I repaired about a dozen strings tonight and chucked three as they had back sockets and or had every bulb blown in a string. The things works good for resettingt the shunts, but I cannot figure out how to get the beeper to find where the voltage stops yet. Good gadget for the money. The bulb and fuse tester work fine, too.

 

[Dusty]

I suggest that everyone here that has light sets that don't work to send them to The Moss Road Orphanage Home for Unwanted Christmas Lights.. Bird.... you said that you are going to throw your present ones out and buy new next year. Put them to good use and send them to Moss Road...
Dusty

 

[RobS]

It worked good. Thanks!

I repaired about a dozen strings tonight and chucked three as they had back sockets and or had every bulb blown in a string. The things works good for resettingt the shunts, but I cannot figure out how to get the beeper to find where the voltage stops yet. Good gadget for the money. The bulb and fuse tester work fine, too.

So you've got the place that the airplanes are mistaking for a landing beacon!!!