Why do my LED lights keep flickering?

I am a drama technician in a school and in one of our drama studios, we have a group of LED lights. As soon as you switch them on, they start flickering, without being altered from the lighting desk they are patched to.

Many people have tried to make them stop before me, and many have failed!

My first instinct is that it may be the binary of the lights. However, it is 3 out of the 6 lights that are doing this and they all have the same binary code (which is, I believe, 11110010).

I've also done some research which says I may need to buy a power conditioner. However, I am not prepared to make the school buy something for them without a guarentee that it will stop the flickering.

Please can anyone help me fix this problem?

Solutions, ideas, anything would be appreciated.

It would help to know the manufacturer and model number of the LEDs in question, also a more precise definition of the flicker. For instance, is it random strobing, cycling through colours, fast, slow. Are all the LEDs doing the same thing or is it random throughout the chain.

If they flicker when the desk is powered off, but stop flickering once the desk is sending DMX, then it may be they have a sound-activated mode, which can usually be disabled by making sure there are no devices in MASTER mode on the DMX run.

sk8rsdad said:

It would help to know the manufacturer and model number of the LEDs in question, also a more precise definition of the flicker. For instance, is it random strobing, cycling through colours, fast, slow. Are all the LEDs doing the same thing or is it random throughout the chain.

If they flicker when the desk is powered off, but stop flickering once the desk is sending DMX, then it may be they have a sound-activated mode, which can usually be disabled by making sure there are no devices in MASTER mode on the DMX run.

Click to expand...

Thanks for the reply! I believe the model number to be LED PAR56R RGB DMX. It's a flick between colours soon as it's switched on at an average speed (1-2 per second), I believe the lights that are doing this lead to each other throughout the chain (so it's probably one that's the cause, which then makes the next 2 LED lights follow?). I don't think they have a sound activated mode either. Hope this helps?

The model number helps but there are a number of manufacturers that make something called that including Chauvet, Eurolite, and any number of Chinese rebranded units. If you can identify the manufacturer then a Google search should find the user manual online. Failing that, post a picture of the nameplate and maybe somebody here will recognize it.

Your description of the behaviour sure sounds like one or more of the units set in MASTER mode and either sending a programmed chase or a sound-activated chase. It ought to be possible to disable it, but depending on the manufacturer the DIP switch settings will be different. If you can find the user manual it should explain what each switch does. I would have expected the DIP switch block to have more than 8 switches, maybe 10 or 12.

What console are you using? Is it analog or digital?(analog consoles that are old have a delay in sending data over long dmx runs) How long is your dmx run? Are you using dmx wireless?

A power conditioner is extremely unlikely to fix the problem, as a first measure check all the interconnecting leads, then check each light individually on the desk and try a dmx terminator at the end od the run.With this information of the results we can give you a diagnosis, without more information there's so many possibilities it would waste a lot of time eliminating all the possible faults.

How are you supplying AC to the fixtures?

Always check cable first. It's the easiest fix. Disconnect all of them, then get one cable running straight from the desk to one light. No splitters, no other dimmers, fixtures, etc. See if it still has issues. Then add in one light at a time. Also, LED fixtures and 99.99999% of all other lights that accept dmx DO NOT like power coming from a dimmer. Make sure all the fixtures are plugged into a wall outlet, etc., and NOT to your your dimmer rack.

len said:

Always check cable first. It's the easiest fix. Disconnect all of them, then get one cable running straight from the desk to one light. No splitters, no other dimmers, fixtures, etc. See if it still has issues. Then add in one light at a time. Also, LED fixtures and 99.99999% of all other lights that accept dmx DO NOT like power coming from a dimmer. Make sure all the fixtures are plugged into a wall outlet, etc., and NOT to your your dimmer rack.

Click to expand...

I would also assure that the dmx run is terminated. This is a snubbing resisitor across the signal hot and common at the dmx output of the last fixture. Terminator, DMX.

meatpopsicle said:

This is a snubbing resisitor across the signal hot and common at the dmx output of the last fixture.

Click to expand...

Erm, no.
It's a resistor between data + and data -, ie. pins 2 & 3. It should not have any connection to data common, ie. pin 1.