# Neon sign troubleshooting questions



## JohnnyGreenbomb (Sep 17, 2008)

Today I went on a service call to a customer that has one letter out in their outdoor neon sign. I'll be the first to admitt that my experience with neon has be very limited. I went online before going on the service call to get a crash course in neon signs and troubleshooting them. There were a couple questions I came up with after going to the job site today that I cant find the answers to anywhere and was hoping someone here help me out on.

1st- With a neon tube de-energized and completely disconnected from the xformer, should you be able to detect continuity through the tube if you test from each end of the tube at the electrodes?

2nd- Could a failing xformer still only illuminate half of a neon tube?

Any help or neon sign troubleshooting tips anyone is willing to share would be very much appreciated! thanks


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## cdnelectrician (Mar 14, 2008)

I have a little experience with neon...first of all there could never be continuity across a neon tube as there is no filament inside it. And it is possible you have a bad transformer...sometimes the insulation can go bad and you will get tracking inside the case. Usually we just contract stuff like this out to a sign company. How big is the sign?


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## JohnnyGreenbomb (Sep 17, 2008)

The sign is on a bank's corporate office building and is a little bigger than your average bank signs I suppose. The letter "K" is not illuminating. Each individual letter is probably 3'h x 2'w approx. and if stretched out straight the "k" would be I"m guessing 6' - 7' in length from end to end. Each letter has it's own xformer. The output on the secondary is 5kv and 30mA. We normaly don't do sign stuff either but we do all of the lighting maintenance and minor electrical projects for all of these banks in most of my state and understandably the bossman wants to keep these guys happy and do all we can for them because they pay their bills always without any hassle. He also has been wanting to start doing more sign work since we get quite a few calls asking to do so and we already are equiped to do it. If it were my choice I'd choose to pass it off to the sign guys as well.


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## subelect (Nov 25, 2007)

If each letter has its own xfmr, is it possible to connect the suspect neon tube to a different xfmr and see if the problem stays with the tube or moves with the xfmr?
In my experience, it is difficult to track down the correct xfmr and ballasts for these signs unless you can still read the labels on the existing ones.
Rick


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## Billy_Bob (Aug 25, 2008)

subelect said:


> If each letter has its own xfmr, is it possible to connect the suspect neon tube to a different xfmr and see if the problem stays with the tube or moves with the xfmr?...


That is what I would do. Or if a fluorescent light fixture not working, I'll do the opposite. I'll take all the bulbs out of a working fixture and place them in the broken fixture and see what happens. Quick troubleshooting!


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## JohnnyGreenbomb (Sep 17, 2008)

That is a good idea and I will try it if I can. Has anybody every used a neon tube tester or spark coil to test the tube? How do they work, not the theory behind them, I mean are they a waste of time and money or are they helpful? thanks for everyone's in put so far!


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## cdnelectrician (Mar 14, 2008)

Can you disconnect the Xformer from one of the working tubes and connnect it to the letter "K" to see if it illuminates? I'm guessing you have a bad transformer...neon tubes usually last a very long time. Also you might try checking the resistance on both primary and secondary of the transformer in question and compare the readings with a working transformer of the same size. Also check all the connections on the HV side and make sure the transformer case is grounded properly. Also, if you do have Allanson ballasts and transformers available to you these seem to be the best out there...expensive but they last!


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## leland (Dec 28, 2007)

JohnnyGreenbomb said:


> If it were my choice I'd choose to pass it off to the sign guys as well.


 
Bad attitude!! 

We already have lost the Air conditioning and control work. How much more do we want to relinquish?
We're still clinging on to the fire alarm, mostly lost the security/access control and totaly lost the data..... Lets not lose any more.

basic trouble shooting as described above will figure this out.
And think of what you'll learn along the way.

If it was easy everyone would do it.


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## John Valdes (May 17, 2007)

leland said:


> Bad attitude!!
> 
> We already have lost the Air conditioning and control work. How much more do we want to relinquish?
> We're still clinging on to the fire alarm, mostly lost the security/access control and totaly lost the data..... Lets not lose any more.
> ...


Gotta love ya man! :thumbsup:


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## JohnnyGreenbomb (Sep 17, 2008)

Bad attitude? Really? IMHO, I wouldn't be here at a forum in my free time trying to figure out how to better my knowledge as an electrician and figure out how to trouble shoot neon signs for my company so we can broaden or scope of services we offer if I had a bad attitude. Right now I'd currently like the sign guys to do this for me so I'm not wasting the time of a good customer because of my lack of expertise in this area. Please don't stand back and pass judgment on me, You don't know me as I don't know you.


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## leland (Dec 28, 2007)

Johnny, That was not personal!
That was a specific statement,to a specific comment.
I understand your keeping the customer happy, thats the important thing.I have subed out and been subed out, you gotta do it sometimes, yes. 

It's just in my 23 yrs at it I've seen alot of our trade go out the window because some were to lazy or scared to persue it.

The more we do and keep "in house" the less the chances of us slowing to a stop when building takes a down turn. As is the case for quite a few here in the USA right now.


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## sparkie (Apr 2, 2008)

if each letter has a transformer you can compare resistance readings of primary and secondary windings-of two of the transformers.


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## JohnnyGreenbomb (Sep 17, 2008)

Leland, sorry to jump on you like that, I understand where you were coming from and why you said that. I'm like you I'd rather keep our scope of work broad rather than turning every little thing into a specialty trade as at least in my area the trend seems to be happening more and more daily. To me one of the best things about this career and trade is the opportunity to be working on something completely different than you were the previous day.


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