Channel Stuck?

Synchronize

Active Member
It's quite odd. Channel 15 at my highschool is like possesed. Sometimes, it would just come on in the middle of the night. The wall controls would show the channel as off, but sure enough it was lit up. It would always be off by morning again. But, just recently, it decided not to go off. We were cleaning up after play practice one day, we just turned off the light board and channel 15 lit up. We turned the board back on and it showed no power going to it so we just packed everything away and expected it to be off by morning. Well it wasn't, and wasn't the day after, or the day after that. It was on for 5 days straight and never turned off. We finally turned the light board on, got the big ***** ladder out, and unplugged the light, then replugged it back in. It was off, so we turned on the channel on the light board. It turned on no problem. When we went to turn it off the board showed it as 00 but it looked as though it only backed down to about 70. We tried plugging the fixture into other channels and other fixtures into channel 15. We deduced that it was not the lamp, but the channel. Any ideas what would cause this, or what we could do to fix it?
 
But when its unplugged, the plugged back in, the light stays off untill activated. And once its on, then turned off, it doesnt stay full, it backs down to around 70 and stays there. Its almost as if the channel is only getting part of the signal.
 
It would be unusual for an ssr to be intermittent, usually they blow "on" and stay on.My guess would be a module electronics fault.There is no way it could ever be a lamp fault, it would seem the module is accepting the up signal but is not responding to the down signal, nothing to do but send the module back for repair.
 
By module, do you mean the rectangular box with four recepticals in it? Sorry, I know I'm a total newb at this. Sad part is, I know more about it than anybody at my school :(.
 
I can only give you a general assessment of the fault, you should not attempt to go any further to fix this problem, it is dangerous to go into dimmer racks unless you know exactly what you are doing, please pass on the information that it is almost certainly a fault on ch 15 dimmer module and have a technician/electrician deal with it.I fully endorse letting students get involved with tech work and it may be useful to watch how to do it but do not at this time do it yourself.
 
So how would I even go about finding somebody to do that? The maintinance dept doesnt know anything about it.
 
David, just noted your post about intermittence. I will note that a had an issue like this, but not replicate-able, just random. It makes me thing maybe this is a data error, levels being sent? Something? It's 3 AM and... yea, sorry I'm of no help.
 
Sync... if your school has an electrician he/she can get parts to fix it, but in my experience they usually don't want to mess with this stuff. You probably just need to have your local theater shop repair it.

Tell us a little more about the dimmer rack. We are assuming you have a dimmer rack that looks something like this. A series of boxes with circuit breakers on the front? The modules may also be short and wide and look more like drawers than boxes like this. It would be really nice if you could post a picture of your rack as we can tell you exactly what you have. Or if you look around to find a brand and model that would be great too.

As David said, messing around inside a rack is an easy way to get yourself killed. I've let students work in my racks but only when a) I'm in the room supervising and b) the power is locked off. So I want to stress that the ADULT in charge of this at your school is the one who needs to take care of this. What they need to do is take the dimmer out of the rack and take it to your local theater dealer and have them repair it. You can have the dealer come to you but it will cost a lot more.

SO here's the plan to SAFELY get this fixed.
-First as noted above, let's figure out what kind of a dimmer rack you have.
-Second if you don't know where the nearest theater repair place is tell us what city you live in and we can help you find one near you.
-Third have the ADULT in charge of the theater call the repair place, tell them what brand/model dimmers you have, and ask for instructions of how to remove the bad module to take it in for repair. Then that person needs to do the actual removal following those instructions.

When you see it removed, you are going to think we are crazy and far too cautious. However, not to insult you, but someone with so little knowledge is taking a HUGE risk by messing with this stuff. Remember if you have a full size 96 dimmer/2.4k rack it is providing 230,000 watts of power and 1,920 amps... it only takes one amp to kill you. So again PLEASE let us help you determine what equipment you have and give you the information to share with the adult in charge to follow the directions of the local repair place.

Others who read this please don't post/P.M. instructions on how to remove a module. Let's keep this young tech alive long enough to learn how to do it the right way from someone who knows what they are doing.
 
Ok so my highschool is in the middle of a corn field. Its a little country highschool with 750 students. We don't have an on-site electrician, and the teacher incharge of the drama dept is more clueless then I am. I have no clue what brand anything is, it all just looks generic. I'm in Richmond, IL 60071. I'm guessing that the nearest place is Breber Music in Elkhorn, WI. Thats what most of the stickers say on the sound equipment. The idiots that ran lights an sound befor the team we have now were complete idiots. Nobody ever thought it might be a good idea to save any paper work on any of our equipment. The highschool is about 10 years old, but believe me, we dont have state of the art equipment.

I'm going to keep assuming that the "module" of which you speak is a rectangular box with four recipticals for the lights in it. If so, why would it be the whole module if only one channel in it is stuck?
 
If you have access to a digital camera, take a pictures of the various parts of your lighting system and post them here.
 
So, everyone seems to be thinking a dimmer problem, but I'm thinking that you have some problem in your DMX line. It is not unheard of for fixtures to ghost on when the console gets shut off, especially if the DMX signal runs through various other devices (Unison system et al).

What kind of lighting console is this? Are your house lights controlled by this console, and do you have wall push-button switches around the theater to turn on the house lights? Do you have any sort of back-up console next to your main console? In short, does the DMX line do anything besides go out of your console and into your dimmers? (The DMX line is that 5-pin cable that comes out of the back of your light console and goes, somehow, to the dimmers to control them).

When the lighting console is on, do you ever have this ghosting problem? If channel 15 is ghosting, and you turn the console on, does channel 15 go off like the console tells it to?

If you answer no to question 1 and yes to question 2, the easiest solution would be to just turn the dimmers off when you turn the console off. There should be a large switch on the front of the dimmer rack, just flip it to the off position. No power, no ghosting light. It doesn't ghost when the console is on, so no worry during shows.

If not, well, let us know and we'll figure it out.
 
My original post answers most of your questions.

It's quite odd. Channel 15 at my highschool is like possesed. Sometimes, it would just come on in the middle of the night. The wall controls would show the channel as off, but sure enough it was lit up. It would always be off by morning again. But, just recently, it decided not to go off. We were cleaning up after play practice one day, we just turned off the light board and channel 15 lit up. We turned the board back on and it showed no power going to it so we just packed everything away and expected it to be off by morning. Well it wasn't, and wasn't the day after, or the day after that. It was on for 5 days straight and never turned off. We finally turned the light board on, got the big ***** ladder out, and unplugged the light, then replugged it back in. It was off, so we turned on the channel on the light board. It turned on no problem. When we went to turn it off the board showed it as 00 but it looked as though it only backed down to about 70. We tried plugging the fixture into other channels and other fixtures into channel 15. We deduced that it was not the lamp, but the channel. Any ideas what would cause this, or what we could do to fix it?

We never had the light go on while the board was in use prior to it staying on for 5 days straight. Then again, how often do you use a light board in a highschool? 6 weeks a year? It never came on in the day either, always at night. Yes, the DMX runs through multiple wall pannles. All of them show that it is off. I dont know in what order it runs throught the pannels but all I know is that when you turn the board on the board takes over the wall pannels. It doesnt matter what you do on the wall, the lights only take commands from the board.
 
Based on your location, your system was most likely sold and installed by Grand Stage, DesignLab Chicago, or Chicago Spotlight. And you're not far at all from the factory of one of the two best lighting companies in the world, ETC. Find "the dimmer room" or where ever there's a rack like gafftaper posted. There'll be a nameplate on it, somewhere.

I'm going to keep assuming that the "module" of which you speak is a rectangular box with four recipticals for the lights in it. If so, why would it be the whole module if only one channel in it is stuck?
No, that's the outlet box; the actual dimmers are in a room somewhere, or maybe in a corner backstage, in a rack. Since you have wall panels, you have a fairly sophisticated system. Do your panels look like the attachment below?

Take and post pictures, and we'll help you identify whom to call.
 

Attachments

  • UnisonStations.jpg
    UnisonStations.jpg
    13 KB · Views: 206
Yeah, that is the type of dimmer rack that we have (just with a lot more dust).

As for the wall pannels, I think that one looks similar, the other two are different. I'm going to see if I can get into the school today to get some pictures. If not I'll have them tomorrow.
 
I have actually run into a SCR pack (two SCR's in same device but not SSR) that did that! It was on an EDI scrimmeret. (spelling) Anyway, would come on at random, but you could clear it by unplugging the load for a second. Had me scratching my head looking at control problems, but that odd reset gave it away. Changed the device, everything was fine. That being said, I would STILL think along the line of some control problem first! (The other 99 times I've run into things like that, it was always control!)
 
Ok, so I havent been able to get into the school yet, but I am almost 100% sure that all of the equipment is made by Lehigh. This is what our wall controls look like. The white (kind of pink looking one, but they are white in our school) one in the very back is what the one in the light booth and backstage look like. The black one in the very front is what the one in the auditeria lookes like. The dimmer box is like the one that gafftaper pointed out, but I'm pretty sure its made by Lehigh. This is our light board, just a much newer, nicer version. Ours runs Windows '95, is 24/48, and only has one video output; otherwise it's pretty much the same. I'll still get pics of all of our stuff tomorrow.
 
Ok, so I havent been able to get into the school yet, but I am almost 100% sure that all of the equipment is made by Lehigh. This is what our wall controls look like. The white (kind of pink looking one, but they are white in our school) one in the very back is what the one in the light booth and backstage look like. The black one in the very front is what the one in the auditeria lookes like. The dimmer box is like the one that gafftaper pointed out, but I'm pretty sure its made by Lehigh. This is our light board, just a much newer, nicer version. Ours runs Windows '95, is 24/48, and only has one video output; otherwise it's pretty much the same. I'll still get pics of all of our stuff tomorrow.

With special attention to dimmers.
 

Users who are viewing this thread

Back