I have a Hog 1000 used to light a small stage with 12 moving yokes (power spot 575 and accu spot ii), along with a large number of LED wash lighting fixtures. Over the past year, I have noticed that the moving yokes are "hunting" more and more. By hunting, I mean it is placed into a position, and sometimes it begins to twitch (either the pan or tilt) until it is slightly moved. I also have a few colors that are not available because of this hunting (e.g. I can not lock on to certain colors). This problem seems to get worse the longer the board is in use, so I thought it might be a heat related issue. I have never opened it up so I do not know if there are fans inside, similar to a desktop computer, that might have failed. Heat is only a theory; there maybe some other problem that might be causing the hunting, not sure. What I do know is this condition can be seen in all of the moving yoke fixtures (both the accu spots and the power spots), so I do not believe it to be a fixture library problem (and they have worked better in the past with the same library). I do not see it much (if at all) in the wash lighting. Does anyone have any ideas how to resolve this problem? Is there something inside that has failed that could be replaced?
Let me add a few other details that may be pertinent: All of these instruments are down stream of several DMX splitters. All of the individual chains are terminated. All of the moving yokes and the LED wash lighting are powered by several relay packs, which are turned on and off (parked and unparked) by the board. The problem (hunting) can be seen both when using the programmer/wheels and during playback. I have not hooked up a single moving yoke to board directly, but I am planning on it.
Hello, if fixtures are twitching it could also be due to a data issue such as needing a terminator in the last fixture at the end of a data line, or a cable on the edge and starting to fail. You mention connecting a fixture directly to the console and I agree that would be then next thing to try. You can then add more little by little until the problem appears. You also mention the wash fixtures do not have this problem. Are they on the same data line/patched to the same output on the console, or are they on a different output? If they are on a different output in may explain why they are not effected.
Some are on the same chain and some are not. There really is no rhyme or reason to what fixtures are connected to what, other than location; however, there is no chain where we exceded 32 (in fact I do think we have over 25 on a single chain); but all chains are terminated. We did check a number of the cables for operation using a DMX tester - in particular, the ones in the ceilings and the longer runs. I can not positively say we checked every 3 and 6 foot cable in use. I was guessing the wash lighting doesn't have the same problem because if I was using a specific color, say lavender, I do not think I would see either the red or blue leds change intensity to a point where it would be noticed (e.g. oscillate in intensity by 1 or 2%). You can see pulsating in the wash light at very low intensities. Use Lavender as an example. Say it was at 10%, but the red might be at 2% to make the color. Pulsating of the color can be seen here but that would be between the red turning off and being on; this I attribute to the fixture itself and do not see as a problem since running wash lighting at such a low illumination doesn'y really light anything. I can not say if I have seen pulsating in wash light between say 3 and 4%, which is something else that I will try.
For what it's worth, the problem was localized to universe 1 (it's an internal board problem). Repatching everything to universe 2 seems to have corrected the problem. I see nothing on the board that is user replaceable, except for the two communications chips (at least I think that's what they are).