Control/Dimming Lightronics DB-612 Dimming Problems

[BLPisani]

I've moved venues within the same company to one that uses one Lightronics RE-121 and 7 DB-612. We're mainly using ADJ and "Guangzhou Special" movers (not the company name, but does it really matter? They're all Chinese crap) on hard lines, but the dimmer pack and bars have some Source-4 PARs, Source-4 ellipsoidals, and Altman 3.5Qs plugged in that need to be dimmed. Here's the problem: only one circuit on each bar dims, and it isn't the same circuit. The dip switches are all set to dim and not relay. They're 1.2kW dimmers per circuit. They respond to DMX, as they're normally off, but at 5% from the console they snap on like a relay or like they're under-loaded and need a ghost load. They're 575W or 300-500W (I didn't check) lamps, so I know that can't be it. Any ideas?

I think I can rule out the console, although there are other weird issues with it, too. That's a Martin M2GO with 3-week old software. Of course, "UPDATE" doesn't work, so it's possible. They are patched as Dimmer 8-bit, so that could be a thing, but I don't think so, because some of them work.

Thanks in advance for any help. We're using Leviton packs until we can get these fixed.

 

[Amiers]

Sounds like faulty electronics in the bars. Cause there isn't anything to them at least from reading the manuals and cut sheets.

 

[microstar]

Sounds like the input power to the DB612's is not wired correctly. They will not operate correctly if wired with 2 legs of 3 phase for single phase operation and, more importantly, will not operate correctly on 3 phase if the phase sequence is incorrect AND/OR the phase jumper on the pc board is set wrong.

From the manual: "When operating on three phase power, the DB-612 expects a particular phase sequence for these 3 input power connections. It does not matter which phase is connected to the L1 terminal but L2 and L3 must be in the correct order. The unit will not be damaged if these two connections are reversed but dimming will not occur correctly and some channels will appear to be in a on/off mode. If this occurs – see the “Phase Sensing Jumper” section in this manual and set the jumper block for 3 phase reverse operation."

This is easy to miss by an electrician. The DB-612 is a very reliable unit in my experience (Lightronics dealer).
I would suggest downloading the manual and reading it.

 

[BLPisani]

This makes sense, except they're an old install. The company I work for owns the theatre (and several others in a tourist town), and this is the 4th show to go up. The show before was by another company that rented the theatre. These light bars worked reliably up until that rental, and possibly through that rental. I doubt that the wiring on them was changed, but it is possible. The routing on a lot of things is weird. The place was built in the late '70s, I think, and things have been added on or taken out without proper documentation. Their breakers, however, are clearly marked and work.

I have no doubt they're good gear. They have some interesting features I like (rotary indexers for DMX addressing, for a start). This is definitely something I'll bring up, though.

 

[FMEng]

It could be as simple as failed DIP switches. A liittle oxidation is all it takes.