Help with Ghosting

[Villuminatrix]

Aloha!

I work in a theater with Strand Dimmers, Martin intelligents, 8 Source 4 LED Lekos, 16 Source 4s with Seachangers. About 2 months ago I was having problems with my Seachangers and Lekos ghosting (not the LEDs) slightly... here and there a seachanger would slowly go into a green and back to NC and back to green... (it was always into green, which I thought was weird) or the leko itself would ghost- on, off, on off. Since the problem fixtures were all on the same dimmers I switched them out and that seemed to fix the ghosting for a couple of weeks.

A few weeks ago, a different set of lekos started ghosting, BADLY. It looked like a disco in there because of how they were flashing - and within two days it was ALL the non-led S4s. The only way to stop it was to turn the dimmers off. I switched out all the dimmers with the problem lekos - only this time no fix.

I read on other forums that sometimes an optosplitter can cause this. We have splitters, and I have yet to see if the lekos are all on the same splitter (I imagine that to be the case though). Because I switched out the dimmers and I'm fairly certain it's not the cabling, it seems the optosplitter is a good bed.

If it IS the optosplitter, what are my choices - repair or replace?

If it's NOT the splitter - any other advice?

Thanks!

 

[JD]

If it were not for the seachangers, I would have said you were developing a problem in the rack. The color changing indicates a DMX problem. You didn't mention anything about the board, and there is where I would start. Pull the DMX line out of the board. The dimmers should either lock at the value they are at, or go to black. If on the other hand, things go crazy, then you are picking up some noise in the DMX line. If everything goes quiet, then you have a board problem.

 

[Villuminatrix]

If it were not for the seachangers, I would have said you were developing a problem in the rack. The color changing indicates a DMX problem. You didn't mention anything about the board, and there is where I would start. Pull the DMX line out of the board. The dimmers should either lock at the value they are at, or go to black. If on the other hand, things go crazy, then you are picking up some noise in the DMX line. If everything goes quiet, then you have a board problem.

Thanks for the quick response! I shut down the board - maxxyz compact- completely- cutting power to it - and they continued to ghost. I'll pull the dmx line separately though, for sh.. and giggles. =)

 

[WooferHound]

Are you using any DMX terminators ?

 

[Villuminatrix]

Are you using any DMX terminators ?

Sure am.

 

[ElGusto]

How are you powering your seachangers?

 

[Robert]

I have had problems with Strand dimmers ghosting when there was a heat buildup - faulty fan. The only way I could figure the Sea Changers going bad would be possibly if the DMX was passing through the dimmer rack and was being corrupted by that. Maybe you have two problems. Always difficult to diagnose when it's two.

 

[David Ashton]

check that the common line on the dmx is not earthed, you could have earth loop problems, then draw a schematic of your dmx runs, this might help pinpoint the area where a problem is likely, there are so many possibilities that much more information is needed unless we get a lucky guess.

 

[Zel]

I wonder if this would be a good time to invest in a DMXer (DMX tester) to see exactly who's talking and what's being said?