DrV

If the drivers are socketed, swap the one(s) in the suspect channel with another one and see if that moves the problem elsewhere.

DOH! Yes, you're right about the transformer. It would discharge any X caps but the resistor is still needed for the Y cap (C1). I've certainly had a shock from an oscilloscope mains filter a couple of times. I don't know what value the cap was but this was definitely the reason. It's not the size of the jolt but the secondary consequences that could be a problem - dropping your hot tea down your leg etc🙂. Sunray's point about the fuse is also valid.

I believe those resistors are there to discharge the filter caps. If you were to pull out the plug when the mains was at a peak of its cycle the filter caps would be left with a charge on them. If you then touched the pins of the supply plug you'd get a small shock. Nothing dangerous but enough to give you a surprise and maybe drop something. The resistors just stop that happening. Changing them to 1 or 2 meg or so will still achieve the same effect but just take slightly longer to discharge the caps. Wait for someone else to confirm what I've said before doing anything. After all I'm just some bloke on the internet!

Or even just a hint as to the type? More info = more useful help

Do the other functions work? Are the lights on full full or zero?

Sounds to me as though the internal +/- 12 or 15 volt supply is not balanced around 0V. Perhaps the 0V connection from the PSU has come loose? Can you check the internal supplies with a meter?

Have sent you a PM. Dave

Yes, almost certainly. It depends on their condition and what the actual fault is but they're usually repairable - old technology. Edit: by the way, I've just looked at your profile and see you're over the Irish sea. Coincidentally I've just repaired a module for one of your compatriots.

I assume you are also at Halifax Playhouse and we are talking about the same system as your colleague, Ged. The power up display is normal. 888 means you have 3 x 8 channel modules installed (most common config for these units). The error code after that I explained above. I don't think the mux lights come on until the self test has completed although I could check tomorrow. I suppose I could simulate the fault code you're seeing but frankly there's not a lot of point as it'll need to be fixed anyway. As I said, I'm happy to look at it and as a last resort I do have some spare processors. From the original post it sounds as though you already have two processors so what was the reason for the initial swap out?

Apart from temperature control I think the other controls are open loop. In other words, the microcontroller commands an action (switch on fluid, switch on air) and simply expects it to happen with no checking of the results.

Well, it took me a few minutes of mental gymnastics, but yes, I see it. Tried to imagine describing a circle on the tabs with a follow spot, which works but then tried imagining describing it on the ceiling and I can see - the wires would get twisted up! Thanks for that Dave

Thanks for replying but that's not the problem. The fixtures are reasonably fast and I did try it really slowly, and with a very small FX size to make sure.

Is it just me? Trying to use a circle FX on some Selecon SL180s and it is moving in a figure of 8. Am I doing something dumb? Version 1.9.9.5

That's great - thanks all. I went for the second eBay ones in the end as the picture showed a red spot which matches what I've got. Thanks to KevinE for pointing that out and to kgallen for spotting the eBay ones. And probably more nutritious 😉

Thanks for all the suggestions (and the PM). I've enquired whether there's a good one available to measure but I now have some things to research. Thanks all.