Some channels/submasters inexplicably full at 1%

I'm using an Express 24/48 board, and I'm having a problem where, randomly, some submasters and some channels will go full when their slider is set to 1% or higher. I have checked, and the issue is not the dimmer profiles -- they are all set to linear. Furthermore, the problem does not appear to be with specific dimmers; e.g. the sliders for channels 2, 5, and 11 all work okay, but my submasters containing those same channels is affected by the problem.

Does anyone know what might be going on here? Any help would be much appreciated!

  • Based on your description, it sounds like the console's fader board mightn't be making a good connection with the brick - was it moved or dropped lately? Check the big, recessed posts with a flathead screwdriver to make sure they're snug, on the back of the brick. The brick shouldn't have any wiggle at all.

    It could also be that some of the ribbon cables inside the fader board have been knocked loose - or if something heavy was placed on the faders, it might be a cracked circuitboard. I'd suggest contacting tech services if it's either of these.

    If you look at the sub list, you can see what the sub faders are reporting as values - [blind][sub][S2] will get you there, I think - see if there's a smooth run up to full as you bring the subs up. If you see a smooth run and there's still issues, it's almost certainly somewhere in the software.

  • Hi JHarpur, thanks for the quick response. I am fairly inexperienced with lighting systems and I'm not sure what 'the brick' refers to; my best guess was the brick on the wall where the board connects to the dimmers by dmx cable, so I checked that connection (the board had in fact been resting on that cable, but repositioning it didn't help me). But based on what my issue was, I'm guessing that's not the brick you were referring to; could you clarify?

    I also checked the sub list, and the submasters do indeed smoothly fade up/down as I move the sliders. Does this mean I need to get the board repaired? (sorry, hate to be the clueless new guy, but I don't know how else to go about resolving this)

  • The brick is the section of the console with the drive in it - the bit that holds the fader panel up at an angle. It also has all the connectors the console uses on the backside (and top, for the 3-pin tasklights).

    If you look at the back face, you'll see two recessed, slotted posts - these are what holds the brick snugly against the fader panel - the other part of the console. As I said before, these two parts of the board should not move at all, independent of one another. If those posts have loosened, tightening them up should eliminate the wiggle, and likely your levels issues as well.

    If you're seeing different behaviour between a channel and a sub containing that channel, the problem is very likely in the console, not elsewhere; and most likely in the connection between the fader panel and the brick, which houses most of the brains of the console. If tightening the posts was unnecessary (no wiggle), then the problem is internal, and I'd suggest contacting ETC tech support and taking their advice on how best to proceed.

    If the problem occasionally occurs on a channel and/or a sub, but only intermittently, the issue may be elsewhere, like a bad DMX cable somewhere.

  • I just had this same problem on 9/29/14 with a block of dimmers in a newly-installed rack (NOT an ETC rack!). On the advice of the consultant who suggested this system, I powered down the rack, pulled out the bottom 4 cards and looked for a switch to make sure the rack was terminated. I didn't see the switch, but I did see a little blue wire that was NOT attached to a bus bar. I put the cards back in, powered up the rack, and all of a sudden the problem was solved. Still trying to figure out why. I don't know what's worse: equipment that doesn't work, or equipment that does work but I don't know why.
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