Lehigh Dimmer Rack problems

Paul V

Member
We have a Lehigh DX Dimming Rack installed at our church. Recently we noticed one row of house lights are not responding to our Collage control unit which is a tabletop box used to select different lighting cues when not using our light board. It is connected to the rack via serial cable. The lights also do not respond to our lightboard. I don't believe there is a patch issue on our lightboard because when I go into patch in live mode the lights don't respond when their DMX number is displayed. There are four lights that are out. They all have the same DMX address and are all on the same circuit. When the lights are supposed to be on, we have no power going to the outlets which the lights are plugged into. I suspect a dimmer module may have done bad. I'm wondering if we had a power spike because about 2 weeks ago we had 4 spotlights all blow their bulbs at the same time. I wonder if we could swap out the suspected bad module for an unused moduel. May be a bad breaker as well. All breakers appear to not be tripped. Any suggestions?
 
it is looking like a bad power cube / SSR so yes the next step would be to turn the rack power off and then swap modules.
After further testing, it seems the module is working correctly. When our Collage control unit is turned on with the house light cue, they work. When I turn on our light board, that row of lights turn off. When I turn the light board off, the lights turn back on. Sounding now like a control issue. The rack does have a control panel on it allowing someone to configure the dimmers. The panel can also run the rack in console mode and run cues. I can not get the control panel to respond to any key presses. Not sure if this problem is associated with the DMX issue or not. I am going to the affected DMX channel in the light board to see if the problem clears. If not, I'm calling a service company. The rack is a Lehigh DX Dimming System with Collage CM100 Programmable Station. Any other suggestions?
 
Well I would get a hold of the manual for the control panel on the rack and try to figure out what the addresses really are for that bank of lights. Sounds to me that the CP is locked so your gonna have to deal with that first.
 
Well I would get a hold of the manual for the control panel on the rack and try to figure out what the addresses really are for that bank of lights. Sounds to me that the CP is locked so your gonna have to deal with that first.
Already know what the DMX address is. Fortunately they are all one address (there's only four lights affected). Going to call Lehigh on Monday to get the nearest dealer that can service the rack.
 
Already know what the DMX address is. Fortunately they are all one address (there's only four lights affected). Going to call Lehigh on Monday to get the nearest dealer that can service the rack.

It's possible that the system is set so that any DMX from the control console will over-ride the Collage unit/system. Once Collage see's valid DMX out of the lighting console, it's control is lost and possibly and only for certain fixtures. ETC Unison can be set to function that way as example.

So once the lighting console is turned ON, it is sending DMX and even though the value for the dimmers in question is zero, it'll still override the Collage. Once you patch and bring those addresses to a value on the lighting console, the lamps should work.
 
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It's possible that the system is set so that any DMX from the control console will over-ride the Collage unit/system. Once Collage see's valid DMX out of the lighting console, it's control is lost and possibly and only for certain fixtures. ETC Unison can be set to function that way as example.

So once the lighting console is turned ON, it is sending DMX and even though the value for the dimmers in question is zero, it'll still override the Collage. Once you patch and bring those addresses to a value on the lighting console, the lamps should work.
Today I tried restarting the dimmer rack control power. The control panel now works and I was able to see what was going on. Turns out the problem DMX address was not patched to either DMX A or B. The collage unit, I believe, is an analog input. After re-patching the lights are again functional as intended. Just don't know why the patching got messed up. I don't believe anyone was messing with it. The panel was working a little flakey which I don't like. Thanks for all the input.
 
Here comes the thred necro! Nothing we have done stops the lights from all turining on when dmx is removed.

Will report back tomorrow after resolved with Karl from Lehigh.
 
Here comes the thred necro! Nothing we have done stops the lights from all turining on when dmx is removed.

Will report back tomorrow after resolved with Karl from Lehigh.
Sounds like "DMX Thump" Basically, as the board is turned off, it throws a bunch of noise out on the line as it dies.
Try pulling the DMX line out of the board while it is still powered on. If-
1) Lights don't come on - then DMX thump
2) Lights start coming on when line is pulled- line is picking up noise and dimmers are trying to see it as data.
In the last case, I had a problem with an install a few years back. Solved it with a "DMX mute switch." Basically, a DPDT switch: one side goes to the board, center goes to the dimmers, other side shorts 1, 2, and 3 together. Cheap and worked.
 
Sounds like "DMX Thump" Basically, as the board is turned off, it throws a bunch of noise out on the line as it dies.
Try pulling the DMX line out of the board while it is still powered on. If-
1) Lights don't come on - then DMX thump
2) Lights start coming on when line is pulled- line is picking up noise and dimmers are trying to see it as data.
In the last case, I had a problem with an install a few years back. Solved it with a "DMX mute switch." Basically, a DPDT switch: one side goes to the board, center goes to the dimmers, other side shorts 1, 2, and 3 together. Cheap and worked.

Ok. I resolved the issue a couple weeks ago.

Lehigh has engineered a fabulous system to resolve the issue. There exists and order of operations configuration that is flexible and robust.

When DMX was lost, the dimmer rack reverted to the "Collage" system, aka "House Panel". A contractor pressed the "Full" button on a panel I didn't know existed. Nor did the auditorium director. Pushed the "Off" switch, and we were all set!

Top marks for Lehigh and their engineer Karl for outstanding tech support on a system that was turned up in 2005!

If anyone has an issue with Lehigh, call them, or send me a message. I'm happy to help. Now, I'm on to a Colortran system. Yay!
 

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