Stuart91

The CASbox is in one enclosure, mounted on the back of the frame. The output from it runs into another enclosure further down which is where all the connection blocks reside. Roughly 1m between the two, and it's also done in 4 core HO7 0.5mm flex.

Interestingly, there were some flickers from one lamp (which began literally as I was starting the engine on my van, ready to make my escape...) Adding a terminator seemed to suppress them so I've advised them to add the resistors to the end of each chain. There's nothing there at present.

That might be interesting once some phantom power gets loose. A few years back a college theatre near me wiped out the HF in all of their loudspeakers. The installers had put every connection on a (non-switching) XLR patch-bay, and some genius had managed to connect a phantom powered mic input to the amplifier inputs, with noisy and expensive results.

Is that an actual physical switch contact like inside a jack, or do they use some other method to detect an ongoing DMX chain?

Me too! Although I suppose it makes sense, as there's no other way of setting the address on the LED drivers. I was anticipating a hidden set of dip switches somewhere but I guess that wouldn't make sense on an IP rated unit.

Thanks, Tim. Yes, all the other fittings are wired the same way, and as far as I can see all of the other "clusters" of fittings have been done identically. There are at least half a dozen "troublesome" fixtures now so it's getting a bit fraught. I'll suggest dropping the green connection and see if that improves anything.

I've taken the casing off the faulty fixture today. Inside is a PSU and fairly generic looking LED driver. I'm getting continuity on the brown, blue, and black cores, but not the green. If as I suspect, it's some sort of power supply, I suppose that would make sense. But the driver unit has a separate power supply, which leaves me scratching my head as to why the DMX signal requires an additional (presumably DC?) feed along with it. However, when I traced the wiring back in-situ, these connections are wired back to mains earth. Again, there's no obvious reason why, although I'd expect the spark who did the install looked at the colour-coding and figured that they needed to go to earth.

I was back at this job today (for my sins...) What we've managed to establish is that fixture number four in the chain is the one that seems to be causing the problems. Omitting it from the chain means that the other fixtures all work as expected. I did try wiring fixture four into the end of the chain, but it still caused the same problem (the first two fixtures in the chain not working). The fixture has now been removed entirely, and I'm going to go through it on the bench and see if there's anything wrong with it. So far I've only been able to ascertain that it will respond happily to a DMX signal by itself. It looks like, in the meantime, another four or five lights have stopped working in similar fashion in the other clusters, so there'll be more to be done no doubt.

I wonder if Silcone lubricating spray (like this ) would work? Might be easier to apply than talc.

I can't speak for radio mics, but have used IEMs in both 65 + 70 simultaneously without any issues. (A mixture of G2 on Ch70 and G3 on Ch65, four in each space)

Is there a "move whilst dark" option somewhere? I got caught out by this on some movers from another brand. Someone had hired them from me for a theatre show, using them as specials so the "move whilst dark" made perfect sense. In some kind of programming glitch, the setting stayed in effect, even when there was no DMX present and the movers were running in standalone mode. Had me scratching my head for quite a while. You could see that the lamps were on inside the fixtures, so I was suspecting jammed shutters etc. before I figured it out.

Each fitting has a mains cable (wired in 1.5mm H07) and two cables for DMX. Each of the DMX cables is 4 core 1.0mm H07. They have been labelled "in" and "out" by the spark that installed the system, presumably there was some labelling on them from the factory but that's been removed when the cables were trimmed to size. As things stand, they have been arranged in a daisy-chain configuration, but rather than jumping between fixtures, all the (in and out) cables run into a junction box, where they are linked together using chocky block. So "Out 1" is connected to "In 2" and so on. There is a separate junction box for the mains supplies, which I presume are just wired together on terminal block of some kind. That's interesting. Whilst I haven't opened up any of the fixtures themselves, I can see that there's a separate power supply unit, and an LED driver unit. Both about similar size and style to the LV transformers that you would use for 12v ceiling downlighters. I'm guessing this arrangement was specified so they could be run from the DMX supplied by the casDMX unit, but I wonder if there's also some capacity for this 4c parallel system, that shouldn't be wired up... Another potential clue is that I did notice a bit of a tingle from the blue core, nowhere near 230v, but enough to give me a fright. That might square with the +v power being supplied that way, even if it's not needed.

Whereabouts in Scotland are you? This is a simple enough job but it sounds like you're quite unfamiliar with the kit so you might get on better (and quicker) if a local company or freelance tech pop up to do it for you.

Yep - it's four core H07 rubberised mains flex. (0.5mm) 🙄 This is how they came from the importer/supplier, apparently. I think we all agree it's not ideal and may be exacerbating any problems, but all the other clusters have their fixtures wired exactly the same way, so I'd lose any argument to replace the whole lot.

Looking through the casDMX manual, I think I agree. So it looks like we have the blue core on the 4-core cable connected to DMX ground and the earth coloured core connected to mains earth... That makes sense - reminds me of the "pin 1 problems" that used to plague audio kit back in the day. That seems like a good plan of attack, and certainly less time-consuming than taking everything apart and starting from scratch. The fixtures are all clustered together. They were supplied with 2m long tails, which have been trimmed to fit the short run into the junction box, with no extensions added. With all the in+out jumps we're still 10+m for the total run, but I agree that whilst poor practice it's probably not the root of the problem.

A couple of other bits of information: Control for the system is via a casDMX unit which takes bluetooth control from an app and produces DMX. The DMX connections to the fixtures are run in 4-core H07 (unscreened). Brown and black cores are the DMX positive and negative respectively. There is a blue core, and the earth (green/yellow). It looks like the earth is connected to mains earth. The blue core seems to be connected back to a "return" terminal on the casDMX. The importer/distributor of the fixtures doesn't know what the blue core is for. However, there are three other identical clusters that are all wired the same way, and are operating without problems. The installation/wiring was done by an electrical contractor who is no longer involved in the job, so I'm second-guessing some of the choices that were made when it was being put in...

I've been asked to help troubleshoot some outdoor floodlights. There is a cluster of five, all running together on a single DMX chain from a controller. The main symptom is that the first two units in the chain misbehave, whilst the other three respond as they should. Unfortunately the connections are all hardwired so it's quite time-consuming to try different configurations. However what I've discovered so far is: • Running the DMX signal direct into either of the first two fixtures, with nothing connected to the outputs, and they behave perfectly. • Attach the rest of the chain, and 1+2 stop behaving, but 3-5 work. • Bypass fixtures 1+2, and feed directly into 3-5, and they won't work. • Adding termination doesn't seem to make any difference. What's making it harder is that I have just trailing wires coming out of each of the fixtures, with no easy way to tell whether they are correctly wired internally. I am resigned to having to undo all of the wiring and check every fixture individually, before trying to get it all working together. However I thought I'd mention it here in case there is any obvious fault that anyone could think of that could be causing this misbehaviour?

If you follow that to the logical conclusion, every double socket should have a 13amp fuse fitted in case it's fed as a spur and someone plugs two tea urns into it.

These models will take a 2.5mm flex without any problems. I've sometimes used them for 13 to 16 jumps, (and Crown Macrotech amps...) I'm not sure about matching trailing sockets, though. Possibly the ones in the same range, but I haven't tried them myself. Yes - I'll take a dozen of each please.

The Mixing Station app is available for the DM3. That might be a better option than Yamaha's standard app, it'll certainly be much more user friendly than logging into a web app.

We have also had issues with colourspace on BlackMagic kit. Took quite a bit of digging until we found out what was causing the problems.

The IP rated versions of the LEDJ uplighter are only marginally more expensive so might be worth considering. Truecon rather than IEC and don't have pass-through connectors so are less useful for running from the mains when available.

Funnily enough, I came away with a similar sort of impression. Nothing that I could specifically call out, just a general dislike of the look and feel. Would be interesting to try an Avantis which is very similar hardware but different underlying software.

+1 I've specified Soundcraft for a couple of installations for exactly this reason - it seems to be really easy to make the transition from analogue. Having a full channel strip worth of physical controls is also a big plus. It's a shame that they're not as ubiquitous as the X32 family.

Well, Zoro emailed me this morning to say that my shipment has been delayed, so...