LED lights flash with board off

I have a few old Chauvet ST-4000rgb instruments I inherited. They do the job I want them to do as a colored wash in the lobby, but they flash (blue, if it matters) when the light board (ETC Express) is powered down. They're old enough that they use dip switches. They are not plugged into a dimmer. The cat is trying to type. Any advice?
Thanks.

DMX Death Gasp ?

Gpquinn said:

I have a few old Chauvet ST-4000rgb instruments I inherited. They do the job I want them to do as a colored wash in the lobby, but they flash (blue, if it matters) when the light board (ETC Express) is powered down. They're old enough that they use dip switches. They are not plugged into a dimmer. The cat is trying to type. Any advice?
Thanks.

Click to expand...

1 - Power them down when not in use; this will extend the life of their power supplies and eliminate unwanted flashing.
2 - Keep your cat away from your typewriter unless she / he is CAT5 rated.
Toodleoo!
Ron Hebbard

Express/ion boards are notorious for sending out dmx on shutdown and back then the dimmers just took it filtered it sent it and it went away. The LED lights don’t handle it well so it stores it as last signal and since they are still powered they just eat it up.

Make sure you are clear rel rel clear master down.

A terminator might help. If a terminator is already installed removing it might help. You can play around with the DMX speeds Setup 2 S4 pick a number.

Sometimes a bad DMX cable or interference can make the console mad. As well as newer optos.

Basically the old tech has a hard time with the new tech even if they have dip switches. Some of these maybe work some won’t.

When you say they flash when the board is powered down, do you mean as the board is powered down (which is probably just garbage as the board shuts down) or after the board has been shut down, which suggests the fixtures are picking up noise and trying to interpret it.

Gpquinn said:

I have a few old Chauvet ST-4000rgb instruments I inherited. They do the job I want them to do as a colored wash in the lobby, but they flash (blue, if it matters) when the light board (ETC Express) is powered down. They're old enough that they use dip switches. They are not plugged into a dimmer. The cat is trying to type. Any advice?
Thanks.

Click to expand...

Do they flash once or repetitively?
Toodleoo!
Ron Hebbard

Some time ago, I redid an install that had a bunch of Chauvet pars with dip switches and seem to recall a similar issue. If I remember correctly, we took a shot at implementing an DMX terminator to the last fixture in line which solved the issue. On another occasion, we discovered that the fixtures would go into audio sensing mode when not seeing DMX. All it takes is one fixture to be set to master mode and all in line with that fixture would follow. Maybe worth a shot…

Thanks for all the help. They flash repeatedly, after the board is powered down. I'll try a terminator first, and then work from there.
Thanks!

RonHebbard said:

1 - Power them down when not in use; this will extend the life of their power supplies and eliminate unwanted flashing.
2 - Keep your cat away from your typewriter unless she / he is CAT5 rated.
Toodleoo!
Ron Hebbard

Click to expand...

My cat is young and she is cat6

Is it a kind of random flash or is it a steady flashing? I guess it could be that in the abscence of DMX the fixtures are configured to fall back to some other mode. Ideally you want them to either go to ff, or hold last look maybe (although this could hold a random "deatch-gasp" look).

Any reason why the line wasn't terminated?

Are all the cables of the correct cable type? No mic cables or lengths of random 3-core?

I'm not saying this will definitely solve the problem, but there's no point trying to solve it until you're sure the infrastructure is sound.

Very few things flash when the power is off. You mean you don't turn the power off when you're not using things?

That's a good point, Jon.

However, if a circuit is switched by a solid state relay (don't ask ...) it can be off, but put a very low load on it (like an LED fixture) and the leakage through the relay is enough to charge the capacitors in the SMPSU and cause the fixture to flash. Replace it with a proper, mechanical relay, and that problem goes away.

JonCarter said:

Very few things flash when the power is off. You mean you don't turn the power off when you're not using things?

Click to expand...

Fire flies come to mind.
Toodleoo!
Ron Hebbard

Gpquinn said:

I have a few old Chauvet ST-4000rgb instruments I inherited. They do the job I want them to do as a colored wash in the lobby, but they flash (blue, if it matters) when the light board (ETC Express) is powered down. They're old enough that they use dip switches. They are not plugged into a dimmer. The cat is trying to type. Any advice?
Thanks.

Click to expand...

In my experience it's part of the life cycle of Chauvet LED's. The next stage is going into full random disco mode if the board is powered down. Our protocol includes powering down all LED fixtures before the board is shut down so no one ever has to see the flash.