Leftylampie

That's an interesting thought. I'm away from home now until Thursday, I'll try that then and let you know the outcome. I think you said a few posts ago that putting the wireless tx unit in line between the controller and first parcan fixed the problem. This makes me think it is something electrical rather than a timing problem, since the tx unit will just be a pass through. If you have the controller and the first parcan running but not plugged into each other, and you measure voltage between pin 1 on the the controller and pin 1 on the parcan, do you get a surprising voltage there?

I have the same issue with just one PAR can connected. :-(

It's not an earth loop as the controller is class two (no earth) and I've tried with the ground lifted at one end of the DMX cable (that didn't work). I think that DrV has probably hit the nail on the head and it's something that I'll have to work around, i.e. only use this combination of fixtures/controller wirelessly and use a different desk in the rare situation where I have to hard wire. Thanks for everyone's help. It is appreciated.

Hi, all five of the controllers are different makes/models. All permutations of controllers/DMX leads/fixtures work perfectly well apart from this one particular desk and the PAR cans. For testing purposes I set all of the cans (and some other fixtures) to start at address one and connected them both wired and then unwired to the other controllers one at a time everything worked perfectly with every controller. When I connect the same 'working' wired set up to the problem controllers all of the fixtures work apart from the PAR cans, then when I add the wireless transmitter/receiver into the chain from the desk everything including the PAR cans work perfectly.

Yes, there are no short or open circuits anywhere, all leads and fixtures work without any issues on my other four desks.

Hi, thank you for your suggestions. There is no polarity switch on the desk but I do have an XLR male to female phase reversal adapter (which I have tried). I've also got end of line termination resistors fitted.

Thank you for your help and suggestions, it is appreciated. The desk is a class two and fed by an external PSU and, as such, doesn't have an earth (but obviously it does have a ground on the circuit board). One of my other desks is also a class two and the PAR cans work fine with it. I have now tried the following without any success. 1. Taking the back of the desk to check that all of the pins on the back of the XLR output are connected to the circuit board - They are. 2. Disconnecting the screen inside the XLR Plug at the desk end - the results are the same as in my original post. 3. Tried different (identical) PAR cans - again the same result as in my original post. I'm still puzzled.

Here's an odd one. I have five DMX desks and numerous fixtures all are used in mobile situations and are in excellent condition. I have a small desk that I'm having a problem with. 1. The desk in question works fine both wired and wireless with all fixtures apart from some LED PAR cans. 2. The LED PAR cans work fine both wired and wireless with my other desks without issues. 3. My cables are all proper DMX cables and in good condition. 4. My wireless DMX transmitters & receivers all work fine. Here's the issue... When I connect one (or more) of the LED PAR cans to the desk using a DMX cable they don't work, absolutely nothing happens. When I connect one (or more) of the LED PAR cans to the desk using a wireless transmitter/receiver they work perfectly. When I connect one (or more) of the LED PAR cans to the desk using both the DMX cable and the wireless T/R (i.e. in series) they work perfectly. So, they work perfectly when there isn't a physical connection between the desk and the PAR cans but not when there is. Does anyone have any idea why?