Strange dimmer behavior

We have a SENSOR CEM Dimming Rack with the 48 modules (96 circuits). It must be about 15 years old by now.

Recently I noticed that whenever our ETC ENCORE2 Console was shut down, a lamp on circuit, #80 comes on (full). I can do a CEM Reset to turn it off or it  will go off by itself after about 20 minutes. One msg I saw said #80 "Not Set"!  I replaced the 79/80 dimmer pack to no effect so I'm convinced its a CEM control problem. I even erased all Backup looks just in case somehow something had been set. We actually don't use this function and the clear all did not stop #80 turning on when the DMX signal disappeared. I'm not really sure of what I should/could do next. Ideas most welcome. 

  • Take a phone over to the dimmers and call tech support. 

    My guess is that something is telling 80 to go to full, but the DMX loss behavior is cutting it off at 20 minutes. Backup won't run unless told to, but there is DMX loss behavior. There might also be something else in the system...

  • A short talk with tech support mentioned some old version of EOS could send random DMX during shutdown but to test that I ran black out and pulled the DMX cable out (I.E. No shutdown routine). After about 5 seconds 80 came on! So I like your idea of taking a phone to the dimmer rack. Will do so today.

  • Go to the CEM and do an [About] and check out dimmer 80 (while it is misbehaving) and see what the control source is.  Many systems had DMX A going from console -> to -> Arch DMX In -> to -> CEM DMX A.  Then Arch DMX Out ->to->CEM DMX B.

    Is #80's drive LED (the green one on the D20's right side) on?  It could be a misbehaving D20.  I have seen the powercubes on D20's locking-on when running hot.  Try swapping the D20 (turn the breakers off, code says power down the rack...or full arc-flash protection---you've been warned) to quickly see if it is the module.

    Make sure the config of #80 didn't get changed to something like a 2-wire flo, or swapped with a different module type.

    I have also seen where a CC20 (constant current) that powered the arch processor, got switched with a D20, so what whenever they turned all lights off, the arch stations powered off. And when they turned stuff on with the console, sometimes the preset panels would randomly wake up. I chuckled when I figured out what was going on. 

  • It gets weirder! Yesterday and the day before when we switched off the console ALL lights stayed off as normal. So plan to call ECT with phone in hand was put off And then today, lamp on #80 came back on - after switch off 9back to square one). I'm printing out your reply to take in with me tomorrow and if that doesn't shed any light on the problem will call ETC. Thanks for the help.

  • Went through all we could Yes, LED's on and Dimmer information saying 100% and so on. The D20 has been changed out a couple of times now and al status messages on rack appear to be normal. Sorry for my ignorance but did not understand the ARCH part! (never heard the word used here, before). New twist; From the booth we could see #80 come back on but down at stage we noticed 3 other laps also came on but at much lower levels. But now if you really want to cry in your beer we arranged for me to sit at the rack and have a buddy turn off the console so I could talk to ETC whilst experiencing the problem. And what happened? Well of course the lamps DID NOT come up (this time). We turned the board on and off  to try to get the problem back. We've seen this before so we'll just have to wait for it to come up and then call in. Thanks for the input anyway

  • by Arch...I mean the architectural system...i.e. house lights,  The dimmer rack has two DMX ports (plus a possible network) as input sources. DMX A  and DMX B.  IF you have a house light system, it might be factoring in.

  • Yep, I can see the A and B. We only use one DMX Universe and do no have a house system. So, we'll just have to hope to catch it next time around and call ETC. Quite honestly I have been through about every menu item/tree on the CEM and can't see anything! Hopefully ETC will have some tricks up their sleeves.

  • Hi Robert,

    Some older consoles can send out DMX values during shutdown that can cause certain circuits to get stuck on at random values. Depending on your Data Loss Fade Time on your CEM is set to, these values should fade out naturally on their own after a certain amount of time. Turning the console back on should also cause these levels to go out, since the console would then be sending zero values to those addresses again. This issue potentially could also be caused by dirty or damaged DMX ports / cabling / infrastructure in your system, causing data to get garbled.

    Do you have a notification number from when you called in and spoke to Tech Services? I'd like to be able to take a look at the notes from the calls you've already made to see if I can make a more specific recommendation on what we can try next, since this issue is so intermittent.



    ETC Technical Services

  • Hi Alex, This thread is getting a bit long/old now and some of my earlier comments getting lost. I do have a number but its back at the theatre and if we see this behavior tomorrow I'll call in. Its a pain because today we were set up to call in but of course - we did not see the lamps coming up after shutdown! As to the residual DMX stuff during shutdown I think I ruled that out by simply pulling the DMX plug whilst the board was up and those lights came up 5 seconds later. And, as you say, some 10 -15 minutes later they will go out or I can use the RESET on the CEM to put them out. All green lights and levels within the CEM's Dimmer info menus appear to be the same as if they had been switched on normally. So, this is waiting a re-occurrence when I'm at the theatre and a call to ETC I guess. Thanks for wading I though. Its not effecting shows but the behavior is disturbing.  Oh I should add its a new Element 2 but the SENSOR rack is about 16 years old. It was installed by ETC originally.