Stevens R. Miller
Well-Known Member
Well, yet another middle school is throwing curve balls at me. This one's system is based on a Lehigh DX2 with a rack control system (picture below) and a small architectural control processor with four faders (a master and three that each control a part of the house). The ACP has a Doug Fleenor Designs PRE10-A DMX512 10-Zone Wall Controller with ten presets and and an LED that indicates that it is passing DMX data through it (at which time it gives up control).
We plug our computer into the ACP (we're running QLC+ and using an Enttec OpenDMX), and things work as expected. But last night, we noticed one of the lights flickering. I thought it was arcing, but then we saw that others were doing it. As the evening wore on, it got worse, to the point where it looked like a disco did in my college days (late '70s). We thought maybe the computer was the problem, so we disconnected it. The ACP includes an "all on" preset, and a few others, including an "apron only" preset. When we activated "apron only," we again saw lights that should have been off flashing on and off. By "on and off," I mean a very brief "on" time, followed by anywhere from half a second to several seconds of "off" time. This is with no computer connected.
We cycled the power on the rack and the problem seemed to go away, but returned after a few minutes. Three of us were working on this and all agree that it seemed to follow the same progression each time we cycled the power: the problem went away, then returned after a few minutes, gradually growing worse. I will admit, however, that this observation is more anecdote than science. What is certain is that the problem always returned.
At the rack, each dimmer is in a module paired with another. Each has two green LEDs on it, labeled "A" and "B." We noticed that whenever a light flickered, its LEDs also flickered on its dimmer. We also noticed that, if all lights were off, there was no flicker. This was true when the computer was connected and streaming DMX data too: if even one light was up, others would flicker, but nothing flickered if we set the scene to total blackout.
We tried swapping dimmers that were flickering with others that weren't. The problem stayed with the slot the dimmer goes in, not with the dimmer. We concluded, therefore, that something upstream of the dimmer and downstream of the computer input, was sending sporadic signals of some kind. This would imply that most likely the culprit is either the ACP, or the rack module. We looked inside the rack to see if there was a DMX input downstream of the ACP, but what we found was not a five- or three-pin plug (there's actually just a terminal strip in there that the ACP apparently feeds into), so we couldn't connect downstream of the ACP.
Of course the school has put in a work order for service, but our show is supposed to open on Friday, so I am not optimistic that the contractor will visit before then, much less fix the problem. But we are stumped!
Any suggestions?
We plug our computer into the ACP (we're running QLC+ and using an Enttec OpenDMX), and things work as expected. But last night, we noticed one of the lights flickering. I thought it was arcing, but then we saw that others were doing it. As the evening wore on, it got worse, to the point where it looked like a disco did in my college days (late '70s). We thought maybe the computer was the problem, so we disconnected it. The ACP includes an "all on" preset, and a few others, including an "apron only" preset. When we activated "apron only," we again saw lights that should have been off flashing on and off. By "on and off," I mean a very brief "on" time, followed by anywhere from half a second to several seconds of "off" time. This is with no computer connected.
We cycled the power on the rack and the problem seemed to go away, but returned after a few minutes. Three of us were working on this and all agree that it seemed to follow the same progression each time we cycled the power: the problem went away, then returned after a few minutes, gradually growing worse. I will admit, however, that this observation is more anecdote than science. What is certain is that the problem always returned.
At the rack, each dimmer is in a module paired with another. Each has two green LEDs on it, labeled "A" and "B." We noticed that whenever a light flickered, its LEDs also flickered on its dimmer. We also noticed that, if all lights were off, there was no flicker. This was true when the computer was connected and streaming DMX data too: if even one light was up, others would flicker, but nothing flickered if we set the scene to total blackout.
We tried swapping dimmers that were flickering with others that weren't. The problem stayed with the slot the dimmer goes in, not with the dimmer. We concluded, therefore, that something upstream of the dimmer and downstream of the computer input, was sending sporadic signals of some kind. This would imply that most likely the culprit is either the ACP, or the rack module. We looked inside the rack to see if there was a DMX input downstream of the ACP, but what we found was not a five- or three-pin plug (there's actually just a terminal strip in there that the ACP apparently feeds into), so we couldn't connect downstream of the ACP.
Of course the school has put in a work order for service, but our show is supposed to open on Friday, so I am not optimistic that the contractor will visit before then, much less fix the problem. But we are stumped!
Any suggestions?