Control/Dimming Entire Dimmers Ghosting

[erico3456]

I'm working down at the theater today, and around noon 5 or 6 channels on my dimmer pack started ghosting and were uncontrollable from the board, so I turned off the dimmers and worked on some other things. When I turned on the dimmers later today about 30 channels were ghosting so I started to try and diagnose the problem. After my dinner break I came back turned the dimmers back on and all 48 dimmers are ghosting. Since then I have been trying to fix the problem. In trying to fix it I have:
-Turned on and off the board and reset it
-reset all of the dimmer packs and checked their addresses
-manually flipped off all of the circuts on the dimmers and then turned them back on to control
-unplugged all of the dmx connections and then repluged it all
-tried plugging the dmx into another control board and brought all faders to zero
-turned the dimmer packs off to rest for awhile and then turned them back on.
-tried controlling just one dimmer pack at a time

None of these tries were successful (except them actually going off when i cut power but coming right back on when i put power back through.)

The board I am using is an Elation Show designer 3
I also tried them in a Leprecon 48/96

The dimmer packs I am using are Leprecon MX-2400 dimmer packs and i have 4 of them adding up to 48 dimmers.

I talked to the Tech Director and tried all of his suggestions but he is out of town working on another show.

Any and all help would be greatly appreciated
Thanks!!

 

[renegadeblack]

I'm not quite sure if this would be it, but, is your last dimmer pack terminated? That could cause some issues in the signal.

Also, are your packs set to go to full when they lose signal? I looked at the manual and read that it has a switch for that, but I'm not sure about that ins and outs. Also, is the indicator on the front showing that you are receiving a signal? Lastly, have you tried pressing the reset button on the front?

 

[JD]

Check your line voltage. During the summer, local distribution (electric company) can get weird as they anticipate demand. About two years ago, I came into the church where I work and all 24 dimmers in the sanctuary were ghosting. When I checked the line voltage it was 137v ! Next day, everything was fine.

What an over-voltage does is it pushes up the low end trim to a visible level.

 

[erico3456]

I just looked through the manual and couldn't find anything about a max switch. I also saw that both the over temp and over voltage are on on all but one ( that one just has the over temp light on). i read in the manual that over voltage would cause them to be uncontrollable most likely the problem, but i used a voltage meter to see if it was over voltage and the meter was reading average readings. Still perplexed any help is appreciated. And yes I did press the resets on the front.

 

[renegadeblack]

How about the signal lights?

 

[erico3456]

All of the dmx signal lights are on. I have since been able to get 3 of the 4 dimmer packs to reset themselves (they finally responded to the reset button) but the 4th dimmer pack (not the last one in the chain) is still being unresponsive. Even though i have gotten 3 dimmer packs working and their over temp and over voltage lights went off they are still showing that they are ghosting in channels that i don't have any fixtures in by looking at the output light (not sure why that is so), but the channels i have fixtures in are working fine. I am still only getting the lights to respond to the leprecon board, as they are show no signs of life when plugged into the elation board, even though I know i have it patched right. i would like to have all my dimmers and the elation board working as soon as possible as i have a major musical that opens friday. let me know if you have any suggestions.

On a separate note, the moving lights that I have running through a different dmx chain going into the elation board seem to be working, but the mac 250s are not opening their shutters when i use the elation to tell them to do it, but they open when i manually instruct the fixture to do it. Any suggestions for this too.
Thanks

 

[David Ashton]

This problem is consistent with a lost or bad neutral connection, measure the voltage between neutral and earth on the supply to the rack while you are trying to operate the lights, if it is more than 2-3 volts this is a likely fault.

 

[NickJones]

Check your load, some dimmers stay on at full if overloaded, yours might be overloaded, it sounds like it could possibly be a console issue as your Mac's shutters aren't opening, most dimmers leave on whatever the last signal they received is, if you have access to even a small preset DMX desk, it would be better than nothing for testing purposes, presumably you are using DMX cable not Audio?
Nick

 

[JD]

It is really fascinating how the problem started with one pack and has moved to all of them! As long as your line voltage is somewhere between 115 and 122 volts, it should not be a line voltage problem. Bad neutral maybe... But why did it start with one pack? You haven't had any recent lightning hits, have you? You tried resetting the packs and doing a primary power-off. You also removed DMX from the packs. Still, many dimmers are set to "hold last value" if DMX goes bye bye. What about a simple direct patch with a short cable right from the leprecon board to one pack? What is the level of ghosting? 10% or more like 25% or more?

 

[erico3456]

I took all of the dimmer packs apart and cleaned them and then reset them through the inside, let them rest for a little while, and then got them working, still about 5 or 8 channels across all the dimmer packs ghosting but I'm not really worried about that right now, must move on for the show. Still having a few problems with the Show Designer 3, the console thinks very differently then most other consoles I've worked with. It seems like the fixture profile for my mac 250s is corrupted, as it won't open the shutter, but whenever i control it any other way (different board, or on SD3 as a generic 18 channel fixture) it works fine. I contacted Elation and i think they are going to send me a new fixture profile, but I think i'm going to have to move on for the show before i get it. Thanks for all your help.

 

[FatherMurphy]

The apparent ghosting of channels you don't have anything patched to isn't a bug, it's a feature - the drive LED lights up to indicate 'no load' when it doesn't detect a complete circuit. On the older LD-2400 dimmers, this was a separate LED, but the MX/VX series uses the same LED as the drive indication. The purpose was to let you know when you had a blown lamp, bad cord, etc., while bugging out a patch.

Have you tried disconnecting DMX, then cycling power to the entire rack? This would clear any stray or corrupt DMX signals, and let you know if it's a dimmer problem or a console problem.