Series Circuit testing

[rew]

 Ok Folks I know this is not really radio related but please try to help me get out of the doghouse.  The problem: wifes favorite Christmas tree. Around 500 lights on it and only about 30 will burn. Pulling every bulb and testing them one at a time is more than I can stand. Does anyone have a simple way to find the open circuit(s).  Tried a tone generator and pick like you use traceing wires but could hear the tone everywhere.
 I have thought about connecting a 6KV plate transformer to the plug and see where the sparks come from!
 I feel really dumb asking the people of this board a question like this, but I figure some of you have been there too.
 Even if you cant help,, Merry Christmas to all of you anyway.

[KeithE4]

Ok Folks I know this is not really radio related but please try to help me get out of the doghouse.  The problem: wifes favorite Christmas tree. Around 500 lights on it and only about 30 will burn. Pulling every bulb and testing them one at a time is more than I can stand. Does anyone have a simple way to find the open circuit(s).  Tried a tone generator and pick like you use traceing wires but could hear the tone everywhere.
 I have thought about connecting a 6KV plate transformer to the plug and see where the sparks come from!
 I feel really dumb asking the people of this board a question like this, but I figure some of you have been there too.
 Even if you cant help,, Merry Christmas to all of you anyway.

I take it you have a tree with the lights already installed.  I apologize for sounding a bit condescending (I don't mean to), but did you check to make sure all the strings are plugged in?  Every pre-lit tree I've seen has multiple strings of 30-100 lights that are either daisy-chained or plugged into an extension cord/power strip that's installed along the trunk.  Check each string individually, if possible.  Those that are bad will have to be removed and new strings put on the old-fashioned way.  Most of them I've looked at use the cheap $3-per-string lights you can buy at WalMart.

That's why I don't buy pre-lit trees.

[rew]

 Yes KeithE4 the lights are already installed on the tree. Most likely I will have to replace the lights but I am going to try a few tricks first. The statement I made about connecting the 6KV plate transformer and watching for sparks has given me an Idea.
 No I am not going to use 6KV on the tree!!! But I am going to scale it down a bit and limit the current to a safe level. Waiting on wife to leave so I can try it. I will post Idea and results later.
 I bet this is about the dumbest thing that has been discussed on this board in a while!
 Yes I know $3.00 a strand and replace the lights, you are right. But I have got to have a little fun sometime.
 Keep the Ideas comeing folks.  Fire extingusher is full and insurance is paid. Keep the Ideas coming.

[Studio1]

If 30 out of the 500 are lit, then there is more than one circuit. The problem with tree lights now is they are producing
them in all manner of configurations.

As a kid I was the one that got the lights out each year, checked all the lamps and made sure the string worked.
It was simple, one series circuit - if one lamp went out, the whole lot went out. There were only 20 lamps on the
whole string however, so checking to find the dodgy one was easy.
These days they are coming out with series/parallel combinations, multiple feeds and so on. Some are incandescent, some are
LED, some have fancy electronic controllers to make them chase and flash.

As far as your situation goes, do you have a non-contact voltage stick? These are about the size of a Vivid marker and look
similar. The tip end lights up and it buzzes when it's brought near a wire that's got mains on it.
They'd only be any good though for a simple series arrangement where you have one wire traveling along.
With these modern light sets that have two or more cables twisted to form a loom it would be of no use at all.

[rew]

 I will try a voltage stick and see what it will do. I think these are just a plain series circuit with two wires in string so that may help.

 REW
 Making repairs of a Christmas light string A HI TECH JOB and enjoying it.( well almost)

[rew]

 Well here is my crazy idea. I had to wait for my wife to leave to try this.

 Parts needed:  fire estinguisher,,  just in case.
                       small neon sign transformer, mine was 120vac in and 12KV at 10ma out
                       a variac type transformer
                       a small AC amp meter to read primary current, mine was a 0-1 amp meter

 I connect the secondary of the neon transformer to one string of lights and slowly turned up the voltage on the primary while watching the primary current. I stopped increaseing the voltage when the current started jumping, and when I cut the room lights I could see an arc in one of the bulbs. I replaced it and now that string works. On the second string the primary current took a sudden jump and stayed. I plugged this string into the 120vac and now it works. 2 strings down and a bunch to go.
 Call me crazy if you wish.  I would have to agree with you.
 When my wife left the last thing she said was "Don't burn the tree down!"  She had no idea what I was planning.