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Electrical Issue - DMXIS?


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  • Electrical Issue - DMXIS?

    I have been using DMXIS at home as I am building my rig, and recently bought some new lights (reputable brand and dealer - though I don't want to name either yet). I hooked the first one up to DMXIS (running via my laptop, on battery power), plugged in the power cord, and it didn't even power up. Bad sign. I was a little concerned, so I checked power on the second unit before plugging in the DMX connection. The second one powered up fine and began running through its test patterns. I then unplugged it, brought it over to my laptop (still running on battery power, with DMXIS up and running) and hooked it up, plugged in the power cord...and heard a pop, and now this light won't power up either.

    I bought several of these and don't want to do anything else with the unopened units, to be honest. My question is - can a sufficient electrical signal travel from your computer via DMXIS to fry a fixture? My computer was undamaged, apparently, and when I plug the DMXIS dongle up to my existing rig and power it up, everything seems to work fine. The electrical outlet into which I plugged both units works fine. Any ideas what could be going on here?

  • #2
    I know the DMXis interface is isolated from your light to your computer so it doesn't make sense that it would be sending a discharge of some sort down the line either way.

    Perhaps it's a mis-wiring problem in the fixture.

    Battery power from your laptop wouldn't be ab le to travel to do that.
    There's nothing to see here. It's another day in IDAHO!!!

    My bands Facebook page, https://www.facebook.com/stiff.richard


    • #3
      By chance are you using Blizzard lights that are "wicicle" compatible? If so, there is a very good chance your DMX cable is mis-wired. I've seen wicicle devices shut down with cables that work fine on other fixtures due to swapped wires. I haven't seen one "pop" though. With this, pull the DMX cable and the fixture started working again. Check the fuse on that.

      If not, I don't know what it could be. I highly doubt it has anything to do with the DMXis dongle as that is working with other fixtures.
      Good judgment comes from experience, and a lot of that comes from bad judgment. -Will Rogershttp://facebook.com/SpitShineRocks


      • #4
        More specifically - Blizzard wicicle compatible fixtures need dmx cables that do NOT have the shell of the connector connected to ground. Many commercial dmx cables need to have a jumper cut.
        Moe---It puts the SINES in the basket, or else it gets the hose again.http://www.hotrodmotm.com


        • #5
          Interesting theory, yes, it is a Blizzard light with wicicle compatibility. It didn't just stop working, though. There was a definite pop when I plugged in the dmx cable to unit #2, and it won't power up now (I suspect the same thing happened to unit #1 though I did not hear a pop). Probably a fuse blown. And my cables are actual dmx cables, not mic cables, they are widely available and have never caused a problem. I probably have 30 cables of this brand, of various lengths. How do I test the cables? If the cables caused the problem, would I have to replace all of them or just the cables that go to the Blizzard units? Are there any brands of DMX cables that are known to not have the problem?


          • #6
            You just open the connector shell up and cut the jumper between the ground pin and the shell ground lug. Do it on both ends. Do you have a meter to test continuity? That will tell you if the cable has this connection problem.
            Moe---It puts the SINES in the basket, or else it gets the hose again.http://www.hotrodmotm.com


            • #7
              MI Tee brand cables have the shell grounded and I believe Blizzard sources their cables from the same manufacturer.

              Open one end of the cable and clip the wire going to the ring. Problem solved. You'll probably need to replace the fuse in the fixtures however.
              Bill Cronheim
              Entertainment Systems Corporation
              Back stage since 1965
              Equipment specialist since 1973