Strip light troubleshooting...please help

erosing

The Royal Renaissance Man
Premium Member
I was setting up some strip lights to be used with effects, and I was told that they weren't all working properly, so I found out which ones weren't working and fixed one, but I'm having a bit of trouble with the other. Here is what I've done so far:

-Ran a dimmer check
-tested extension cord
-tested individual instrument
-plugged it all back up

Here is what I know:
-Instrument works (no burnt out lamps)
-extension cord works
-dimmer works
-floor pocket works

I can't think of anything else, but I need to have it working in a few days, and I can't figure out what I'm overlooking. Please help.

Thanks
 
For the unit that still fails, you say that you have done the following:

-Ran a dimmer check
-tested extension cord
-tested individual instrument
-plugged it all back up

And each has passed its test. Correct? However, when you say that you have checked the individual instrument and the lamps were not burned out, did you actually plug it in and check that the lamps fired up? A visual inspection of the lamps does not rule out any other faults with the unit. Sometimes a lamp will fail with no obvious visual damage. I have had some MR16 lamps fail right out of the box and looked perfect. The lamp could not be seated properly, or the lamp base damaged. Is there a fuse on the fixture (probably not on a strip light).

What happens if you swap out one of the working units for this one (keeping everything else constant)? If the working unit works on this circuit then the fault is in the fixture.

In a situation like this I would check the fixture first and if the lamp was not faulty I would check the power coming into the unit with a power tester (such as a GAM check) or a DMM, or simply a light that you know works. If power was present in the feed to the unit, I would remove the unit and test it on a test bench.

Always be wary when powering up a unit that visually appears not to have a bad lamp as a wire inside could have come loose, which could touch the case – the ceramic terminal blocks frequently do come loose, so check those (if present). So I would always suggest testing a fixture on a protected circuit and not to “hot patch” it (perhaps that is a future QOTD). In Australia, we are fortunate that all out receptacles have a switch built into them but this is something that I have noticed to be missing form US receptacles.

If there was no power present in the feed, I would work back to the next component in the line and check again there. Once you have power, you know that the unit that immediately preceded it needs further checking.

It is all a process of selective elimination. Good luck.
 
Yes, I plugged in the instrument and it lit up like new.

It is a three way split strip light, and one of the three sections doesn't work, which is why I'm so confused. I have tested the dimmers and there is power coming from them, and I know the plug is wired correctly, so I'm lost at where to go. I thought there might have been a problem from the board, but I proved myself wrong, I switched to a different instrument and it worked fine in the dimmer.
 
sounds like theres a band connection in your one circuit, open it up and take a look, i wouldnt be suprised if that was the problem.
 
OK – now it makes sense. What you now describe is a strip light that has one segment that doesn’t work.

There is obviously a problem with the internal wiring, the lamp base or the lamp.

Step one would be to remove the lamp from the segment and check it with a multimeter/continuity tester to ensure that it is good. Check the lamp base to ensure that the contacts are good and making good contact with the lamp. You could always swap the lamp form a working segment into the non-working segment. If the lamp lights up a previously working segment, you need to look further. If the lamp doesn’t light up, safe bet that the lamp is dead. Try a working lamp and see what happens.

If the lamp works on another segment, then it is either the lamp base or the wiring. If you have a multimeter or a continuity tester, you could check the lamp base contacts with the plug pins for that segment. I am not sure if you are using a strip light with individual whips or one that has a multi pin connector (we have both types here).

One terminal on the lamp base will go to hot, the other to neutral. If not, you have a wiring problem (possible loose connection or broken wire). If the connections are good then the lamp base will either need to be cleaned or replaced. Can you see any signs of physical damage to the lamp base?

Remember to kill the power to the unit when taking the measurements and also when swapping the lamps.

You may very well have to open up the unit but I would check the lamp and lamp base first. If your unit uses the ceramic blocks to join the whip to the lamp base, check that the screws are tight as these frequently work loose.
 
The wiring is correct, I checked it and it is all good to go.

Sorry I forgot to mention that it is in whips, the segment works fine when it is plugged into a seperate wall outlet, but when I try plugging it into the dimmers, the other segments work, but not the one I have it set up like this:

Dim - Color/segment
------------------------
55 - Pink
56 - Green
57 - Blue

Dimmer 55/Pink is what doesn't work, but I know the dimmer is working, and I know the outlet is good, and I know the instrument is working.

Sorry I wasn't clearer before.
 
What happens when you swap the whips around so that 55 becomes Green and 56 becomes Pink?
 
55 still didn't work
 
Then the fault most likely is with your dimmer or the board or with the extension lead(s) between the dimmer and the whip for your Pink segment.

You said that you tested the dimmer.
What did you do to check this?
Are you able to repatch at all?
Swap the extension leads at the dimmer for outputs 55 and 56. Does 55 still not work?

What dimmer/board are you using? Whilst your systems are different to ours, some things are the same and by posting this info, you will make it easier for others to help.
 
55,56,57 are all on the same dimmer. I reset it after all the testing to see, and 55 still didn't work.

I'm not sure what you mean by extension lead.

I'm on an ETC 48/96
 
By extension lead – I mean a power cable that connects the fixture whip to the dimmer. You may call them something different.

Over here, most of our dimmers sit off to one side of the stage and then we use looms or extension leads to make the connection from the dimmer to the individual fixture. I know that in addition to this method, in the US you also use smaller dimmer modules as well, which would allow you to place the dimmer next to the fixture (correct me if I am wrong).

What did you do to test the output of the dimmer to come to the conclusion that ch55 is working? Have you checked to see that the fuse has not blown on this channel?

If you are sure that the dimmer has no fault, plug the fixture whips directly into the dimmer (assuming this is not the current set up). Does this make any difference? If so, they your fault lies in between the dimmer and the fixture.

What dimmer are you using?
 
What’s not working properly specifically?

If it’s not working it’s not working so what about it is not working?

First do the easy.

Power, can you swap this fixture with another fixture to localize the problem? Process of elimination. If the other fixture works, you know it’s not the dimmers or cable. Go back from there if it don’t work. Replace the cable if it don’t work with a new cable. Works, it was the cable, don’t work, it’s at the dimmer, light board or control cable. Etc.

If at the fixture, you state the fixture works. How did you determine this? Did it beep out on a ohms meter or physically work for you somewhere else?

What circuit on the fixture did not work or do none of them work? (A word of caution about using live power to test equipment that is said not to work. Bad Karma especially if it’s a internal wiring problem.) At very least Mayhem mentions a test bench, to this when working on equipment in question, such a safety circuit is very necessary for your own personal safety. Click the GFCI goes before you ever know what happened. Or click the fuse and or circuit breaker goes. A switch to turn on the power is also very useful so your hand is nowhere near the plug much less fixture in question - this all a part of the bench testing or remote test equipment. Hot patching a fixture is bad anyway.

Given this is the fixture and assuming everything beeped out in a it should work type of way, did you test hot to ground and neutral to ground? Lamps and fixture might seem like it’s all ready to go in beeping out correctly but if it shorts to ground it’s going to pop a circuit breaker. Only way you can tell is by way of metering to ground also.

Next, it works now but after it’s bumped around a bit or moved in general it no longer does. Did while you were doing the test did you do the wiggle test? Often stuff will meter out than when you get it to the location it does not. All it takes is something for now making contact than later being bumped so it’s no longer in contact to make that difference. Just one strand of a wire twisted in just such a way so that for the moment you have continuity will meter out but be nowhere near in workable condition later. From plug, to cable, to fixture to contact between lamp to lamp base lots of stuff could for the moment find descent continuity than once bumped no longer be in contact if not even short to the frame of the fixture.

In having a problem, be more specific, we don’t yet know if it’s a MR-16, RSC, screw based or even PAR 56 or 64 one. In at least the lamp base or in series wiring there will be a lot of differences in what is what.

After this, in now working and playing catch up, is the circuit not working or is the circuit breaker popping?

If the as expected circuit of the fixture does not work, do the easy first. Cut the plug, tug on each conductor to ensure there was not a break, than re-install the plug. While doubtful that a 12ga conductor could break in this application it’s possible. Thus while flexing the plug or whip to the fixture, in some positions it will show contact and in others it will not. This given it’s not a MR-16 or MR-11 strip in which case it’s series and you looke for the indicator lamp of where the problem is. Do the below lamp and lamp base testing and looking at also before you attempt to open up the fixture.

Is the entire circuit not working? At that point and if re-installing the plug does not help, it has to be the wiring if it’s a few lamps on that string. Or is this a three cell cyc that has one lamp per circuit? In that case it could still be a lamp and or lamp to lamp base contact.

If three cell cyc, and assuming that the lamp metered out, how does the lamp base itself look? All kinds of carbon arcing and blackening or looking like shiny brass or is the nickel plating in good shape? Given this is a simple check and if a three cell cyc, that contact would cause problems. A six cell cyc light has the lamps tapped off the trunk (Term?) line and at least one of the lamps would be working if localized to a single lamp base.

If it looks like brass or both lamps on a circuit don’t work, plus the plug and it’s wiring is good it is an internal problem. We have done the easy before we open up the fixture.

Knowing the results of the wiggle test and hot/neutral to ground testing will be useful here. Otherwise it’s more like some wire that has come loose and might be in contact for now but is not later given we have eliminated the lamp base as the problem.

In the lamp itself, how did it’s contact look? Was it dark if not pock marked with arc welding? Did in metering it out it look bad? Might have had the probes to a multi-meter find a place to make contact, but that does not mean the lamp base itself will find that same place. As with the lamp base, if bad, it could meter out but also either be too high in resistance to function or not make contact with the lamp installed into it. Looking at the lamp and it’s contacts is another easy check before one opens up the fixture.

Often what the lamp shows will match what the lamp base is able to conduct. Put a new lamp into a bad lamp base or even a bad lamp into a good lamp base and they will work but heat up alot in destroying the other or will eiter conduct to an extent but heat up under use and perhaps later not conduct, or if bad spot hits bad spot not conduct even if all else seems good but one point of contact. Lamp and lamp base are easily fouled with bad stuff and once one is, it's easy to destroy the other. If this is a newer lamp in a new base one might miss a bad lamp base, but as with doing the easy first, inspecting the lamp is easy, pulling out the inspection mirror and flashlight is one step harder.

If the lamp's base shows corrosion, you can suspect that the fixture base also is corroded. If the lamp does not than you can cross out this part of why a lamp might not work as a cause but not yet the lamp base. Doing the easy was only to look for a cause not cross out all of it. Much less is this the proper lamp. Dependant upon the fixture, if a say 250v lamp, perhaps it's not getting bright enough in a 110v system to note it working. Outside chance, but than of course I do have some 230v HPL lamps much less some 250v PAR 20 lamps, now where did they come from given I live in the land of 120v? A dim lamp can be lamp voltage or fixture high resistance short in having it's own symptoms to troubleshoot.

On internal wiring, your nose and eyes often can quickly determine a problem. Frequently a lamp base’s wiring will melt down as a proximity thing to the lamp base itself. This especially on RSC type lamp bases. It’s completely possible that a lamp base got hot and it’s wiring lost it’s insulation. The wiring than shorted to the frame while in some positions, and not in others. Could be a temperature type of thing too with insulation around conductors shorting out or just plain being broken at a connection point. If inside the fixture you don’t notice anything obvious, give a tug to all wires at the lamp base and any inside connections and taps off the wires leading from male to female plugs. Didn’t mention if it’s a three cell cyc if other fixtues wired from this fixture still work. This is another step in localizing the problem but a less important one given it’s often easy to see.

Hope it helps, I’m still in the dark about this cyc light type, much less what and how you tested it. Also in checking the plug, what were you checking and looking at, much less what type of plug it was. Very many details both to look at and note when asking for help in a way people are only able to surmise off what info you give.

Don't feel bad about not enough info however, I know of many if not most pro's in the field that would not be able to give more info on what is otherwise the process of elimination much less do the easy first and hone in from there.

Be cautious about plugging in a fixture that is noted to be bad. This can often be very to an extreme dangerous given as much info as you have provided or even less in what you were provided that you were told about. This you should never do again in testing while live.

Also if it is currently working and only trying to track down what others have said about it, such a fixture should still not be trusted until in all ways it passes your inspection. There is frequent "Operator errors" in the industry, but only after your absolute best amount of testing and inspection. When it comes down to it, if you can't figure out the problem, don't use the fixture and send it up to the next eschion (sp) for repair - meaning factory or factory service center. Your life is worth more than a design or a show, much less that of someone else in touching what you certify is even more important yet. In wiring there is no room for mistakes.

If it's said it don't work, and it does be absolutely sure that it does safely or don't let it on stage. Less about you and you not finding something about it than others getting killed by what you did not check. Than and only at that point in weighing your inspection abilities to have looked at everything and knowing all about it, than assume it might be operator error. In this case, if the lamps don't work it's not and you need find the cause or pass it up to those that can. Don't use unsafe gear nor let others use it as part of a fixture.
 
Mayhem
-The extension lead does work, tested it seperately
-I plugged another instrument in its place
-I don't know the specific dimmer off hand
-I'll check it with a direct plug tomorrow

Ship
-problem is localized
-Fixture physically worked in another area
-Just one circut doesn't work, each circuit on a seperate dimmer
-I'll test ground to neutral, and hot to ground tomorrow
-wiggle test was unsuccessful: made no difference
-the breaker isn't popping
-the instrument is a 12 cell: 4 lamps per circuit
-the lamps themselves all work
-I checked for corosion on the plug and made sure there wern't any loose wires.
 
Check for any hot patches and other stored cues also.

Good to know it's not a fixture problem. Check this with a third fixture to verify it.

Swapping dimmer cards is after cues a good step in addition to swapping patch and extension jumpers.

In having the dimmer/control/house wiring problem we get into a whole new part of the telling about your system details.

Good that it's not the fixture.

Lots more to do in figuring out what about the circuit don't work.

Fun stuff.
 
I have no idea what was wrong but it was fixed by a fellow tech, so as long as it works, all he said was it was somethign I overlooked.
 
It would be a great help to anyone that has been following this discussion (or may do in the future) if you could post what the actual problem was and how it was detected and rectified.
 
Yes, I will try to, I may not see the tech for a while though, but I will try.
 
ok.

Personally, I would have wanted to know all the details when I found out that some one else had fixed it, especially if they said that it was something that I overlooked.

Don't think of it as a failure by you but a learning opportunity. It is only a mistake if you do it twice.
 
I definately want the details but currently, the only way I'll be talking to that tech is if I punch him first.
 
I make in part my living off finding wee little things people forgot to look at. That's why they come to see me. However since my work load on wee little things is already sufficient, intent is to train others to fix it themselves. Helps me and more especially helps them. Punch the guy in the arm for what ever initial reason, than get him to teach you what he found, much less than punch him again for not passing on the knowledge to you in the first place. Tell him I said to if it helps.
 

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