Lights randomly strobe and flash

Tyler Smith

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Joined
Mar 3, 2017
Location
UK
Hi,

today, our light system (which we use lightfactory to manage) started to randomly flash and strobe and we have to stop them and use house lights- all whilst we had a full audience!

We initially thought the fan had broken in the PC and was over heating, stopping background processes related to lightfactory, thus stopping the lights from operating correctly.

Would this be the problem or what do you think is happening?

All of our motor lights started strobing the audience.

Thanks
 

TheaterEd

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Could easily be a dmx issue. Are you using terminators and proper cables (aka not mic cords)? I've had a similar ghost show up in a system when a fog machine was plugged into the same circuit as one of the dimmer packs, so it could be many things.

In general though, the lights were receiving some sort of incorrect signal, I don't think a pc overheating would cause that, but you never know.
 

Tyler Smith

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Mar 3, 2017
Location
UK
Could easily be a dmx issue. Are you using terminators and proper cables (aka not mic cords)? I've had a similar ghost show up in a system when a fog machine was plugged into the same circuit as one of the dimmer packs, so it could be many things.

In general though, the lights were receiving some sort of incorrect signal, I don't think a pc overheating would cause that, but you never know.
We're using proper DMX cables not really sure about the PC overheating too. Thanks
 

gafftaper

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Sounds like a DMX problem to me. Are your lines properly terminated. DMX has the ability to work with improper cable and without termination sometimes. And then sometimes it just decides it can't handle being missused any longer. The classic symptom of improperly terminated DMX lines is random flashing.
 
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gafftaper

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If the line isn't terminated, the signal can go down a line, hit the end and then reflect back. This causes the fixtures to hear DMX data coming from both directions at the same time. If your devices don't self terminate (some do some dont), you should have a terminator at the end of every DMX daisychain.

It can easily work for a while and then when you add the wrong device to the system it causes it to reflect. It can also just start happening without changing anything.
 
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Tyler Smith

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Mar 3, 2017
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UK
If the line isn't terminated, the signal can go down a line, hit the end and then reflect back. This causes the fixtures to hear DMX data coming from both directions at the same time. If your devices don't self terminate (some do some dont), you should have a terminator at the end of every DMX daisychain.

It can easily work for a while and then when you add the wrong device to the system it causes it to reflect. It can also just start happening without changing anything.
Seemed to be working fine then suddenly all of the lights flashed and the motored lights started revolving, flashing and all headsets attached to the system stopped working.

Will change PC and then see, what do you think?
 

RonHebbard

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Location
Waterdown, ON, CA
It seemed to happen every 10 mins or so and when there was loud stage noise, it would happen again...
What happens every 10 minutes or so? Does your bar have an ice maker that cycles or is there anything else you can think of that happens automatically approximately every 10 minutes or so?
Toodleoo!
Ron Hebbard.
 

JD

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Jan 1, 2005
Location
North Wales PA
all headsets attached to the system stopped working.
Whoo! hold the bus, you just expanded the nature of your problem to include your com system?
That's a biggie. sounds like a cabling problem, or some other large electrical item (HVAC?) starting up and superimposing a lot of noise on the system. Possible big-time ground loop issue.
 
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RonHebbard

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Whoo! hold the bus, you just expanded the nature of your problem to include your com system?
That's a biggie. sounds like a cabling problem, or some other large electrical item (HVAC?) starting up and superimposing a lot of noise on the system. Possible big-time ground loop issue.
But the plugs fit. Y'mean I can't just loop it all together? BEING CYNICAL HERE! BE SURE YOU REALIZE I'M KIDDING!!
Toodleoo!
Ron Hebbard.
 

gafftaper

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all headsets attached to the system stopped working
Are they truly attached to the lighting system some how? Or do you mean that your separate com system goes down at the same time?

I agree that this now sounds like it's something electrical that happens every 10 minutes. Time it to be see if it's exactly the same time or not.
 

JonCarter

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Meridian, Idaho, US
We must believe that your systems (light, com, sound, whatever) ran as they should have in the past, like, since they were installed. When did this trouble begin? What happened JUST AS it began? Think about what could have changed.
 

Tyler Smith

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We must believe that your systems (light, com, sound, whatever) ran as they should have in the past, like, since they were installed. When did this trouble begin? What happened JUST AS it began? Think about what could have changed.
We think that it is actually the DMX -> USB converter as when we used the lights with the old Jester system they worked fine.
 

Tyler Smith

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Mar 3, 2017
Location
UK
Whoo! hold the bus, you just expanded the nature of your problem to include your com system?
That's a biggie. sounds like a cabling problem, or some other large electrical item (HVAC?) starting up and superimposing a lot of noise on the system. Possible big-time ground loop issue.
We think that it is actually the DMX -> USB converter as when we used the lights with the old Jester system they worked fine.
 

TNasty

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Sep 9, 2016
Location
New Jersey
I agree with the fact that it very well could be due to a large appliance such as an HVAC unit kicking in. One thing you can to to test this is to use a multimeter to check how/if the voltage fluctuates on different outlets during the conditions that cause this. I know that my UPS at my house has to do its AVR boost magic during the summer when there's a lot of power draw in the house and neighborhood. It's probably due to an abnormal voltage (probably running in the 110-105 range).

If it is something big, the most you could do immediately is to buy some hefty line filtering unit, such as a UPS (be sure to get real sine, not the fake stuff, since you're dealing with equipment that could easily reflect any abnormalities in power).
 
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Jay Ashworth

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Feb 7, 2014
Location
St Pete FL USA
Note that *most* UPSs are not continuous or line-interactive these days; they're switchover, which is a) half the price, and b) won't have any impact on the waveform until they trip.

We have an in-depth thread on this somewhere that someone oughtta pin. :)