Unwanted Flickering Lights

[Hornsfan71]

Hey guys. Newbie here on this forum, needing some expert diagnosis. Our church is using the Jands Vista M1 controller with the native vista software on a Mac Mini for service lighting, and we are seeing a couple of strange things that we've been unable to solve as yet.

 

One instance is this: one set of (4) incandescent Par cans will oscillate from OFF to full brilliance until we override the programming and turn them OFF. Then we can bring up one or two cans to around 25% and they will hold until the next lighting cue is triggered.

 

Another issue: we have some LED color washes on the stage set, and (1) of them will occasionally flicker from the programmed setting to full white brilliance, lasting only 1/2 second or so.

 

Both cases, we have checked / replaced wiring and fixtures and the problem stays in the same location, so I feel that we have something going on in the controller setup or programming.

 

Has anyone ever seen something like this? Any ideas about where to look next?

 

Thanks in advance!

[flashcrashboom]

If the parcans are being run on a dimmer make sure the dimmers are loaded correctly. I.e that the minimum wattage is on each dimmer - 2.5kw dimmer has 2.5kw of lamps connected, at least 2 X 1kw parcans or 4 X 500w parca ns. This might work.

If the LED fixtures have a self DMX terminator make sure thats switched and if not buy or make a DMX terminator and introduce that at the end of the chain. Try using a DMX terminator at the end of the DMX chain.

[themadhippy]

As above is the DMX line terminated?Another thought is its a DMX timming issue,got the same sort of errors when using a pc to genarate DMX in the past,although that was a diffrent software hardware set up,but it might be worth trying a diffrent computer,

[indyld]

IF this is a geunine "flicker" issue and not finger trouble at the control (the "hold" mentioned, is this the same issue? Not understanding the programming is a big cause of "faults" with less experience):

 

Seeing as you have LED cans AND the dimmers with the flickering issue, this is likely not the dimmers or the loads (only rarely an issue with extremely underloaded older dimmers), but most likely a crap DMX issue. To isolate the issue from either dimmer or LEDs or desk, take the LEDs out of the equation. Then swap out the dimmers in the chain and replace them with the LEDs.

 

Depending on which "half" is causing the problem, you are usually looking at a cable or the In/Outs on the LEDs, possible the DMX output devices/desk or dimmer cards, but less likely. If they are cheap LEDs, I tend to suspect the Ins/Outs more, but this doesn't replace proper verification.

 

DMX issues like this can be a beggar to trace on site, because the problem seemingly moves around. But one way or another, you need to eliminate bits of kit until you find out which bit it is. Take out any buffer and terminators while you fault find, and re-introduce if you want to verify the fault. The terminator will usually break everything more so it's easier to "see".

 

DMX Fault Finding On Site

 

Good fault finding process of elimination speeds the whole thing up, rather than random tweaks. I'd look at all these things first, although the fault description sounds like a number of "different" things.

[brainwave-generator]

If the parcans are being run on a dimmer make sure the dimmers are loaded correctly. I.e that the minimum wattage is on each dimmer - 2.5kw dimmer has 2.5kw of lamps connected, at least 2 X 1kw parcans or 4 X 500w parca ns.

 

I assume you mean just for testing? There is no requirement to load a dimmer to it's full 'capacity' to make it work properly.

[Don Allen]

A clarification of minimum dimmer loadings.

 

Irregardless of the maximum dimmer loading, usually 2400 watts (2.4kW0 or 5000 watts (5kW, there will be a minimum dimmer loading, usualy spectified in the manufacturers handbook. For the older Strand dimmers, the minimum load was 60 watts.

 

As an example, the Jands HP Spec sheet sates " Each of the six (6) dimmer channels shall smoothly control loads

from 25 watts to 6000 watts."

[Fred Mikeska]

Please give Darryl Ross of A.C. Lighting, Inc. a call to help troubleshoot the problem.

 

Darryl provides fantastic technical support of the Jands Vista range and will help you diagnose your system.

 

 

 

Darryl can be reached at (518) 832-3487.

 

 

Fred Mikeska

V.P. of U.S. Sales & Marketing

A.C. Lighting Inc.

 

Hey guys. Newbie here on this forum, needing some expert diagnosis. Our church is using the Jands Vista M1 controller with the native vista software on a Mac Mini for service lighting, and we are seeing a couple of strange things that we've been unable to solve as yet.

 

One instance is this: one set of (4) incandescent Par cans will oscillate from OFF to full brilliance until we override the programming and turn them OFF. Then we can bring up one or two cans to around 25% and they will hold until the next lighting cue is triggered.

 

Another issue: we have some LED color washes on the stage set, and (1) of them will occasionally flicker from the programmed setting to full white brilliance, lasting only 1/2 second or so.

 

Both cases, we have checked / replaced wiring and fixtures and the problem stays in the same location, so I feel that we have something going on in the controller setup or programming.

 

Has anyone ever seen something like this? Any ideas about where to look next?

 

Thanks in advance!

[paulears]

Before you start a big complex review of the DMX chain,have you actually looked at the cue running when the problem happens. Occasionally I've discovered I have inadvertently recorded a cue with some for of effect applied. Maybe I was experimenting with an effect on something like an LED RGB fixture,making one of those slow every colour colour changes, but then just faded it out and added something else,liked it and recorded it as a cue, only to realise later the effect was still running and having an impact on other lights in the cue? What I'd certainly try before you do anything else is simply put that 'dodgy' channel to full in the programmer with nothing else selected and active, record it to a cue, and see if it works. If it remains at a steady brightness, then it's a cue content problem, dimmers and DMX being not guilty. The way I work often leaves unwanted bits in cues. Somebody on stage says "did you know the movers on bar 3 are moving about but not lit?" Very easy to do - somehow I managed to record a cue with a shape applied. Usually it's due on my chamsys to liking what I see, so putting that into the programmer, making a few changes and then recording it. If you do this, you'll also capture things in the cue you can't see. If you look at your problem cue when it's misbehaving, can you see any data actually changing in real time.

 

The clue was when you said putting the channelinto the programmer at OFF cured the problem - suggesting to me the dimmers and DMX system are working fine - leaving the control as the problem source.