Troubleshooting is one of the most important set of skills to have in modern lighting.  It’s also very difficult to teach.  When I look at a problem, I’m barely conscious of the list of things I rule out in the first few seconds and I’m only somewhat aware of what symptoms I’m seeing that tell me where to start. But since having a good approach to troubleshooting is important to success, I thought I’d give something a shot to try to communicate how I approach a problem.

Recently, I was contacted by a friend who was having trouble with an Astera Hydrapanel not reaching 10k CCT.  It topped out at 8800k (measured in man entirely dark room).  For me, my approach to troubleshooting is always to Isolate and Identify.  In the hopes of getting y’all started with troubleshooting, here is the list of things I came up with to test and see what was going wrong.

1. Check the profile and patch (duh) both at the fixture and at the board.  If your address is off by one, you might be seeing a 16 bit value that is split over two parameters.
2. Open a DMX view that shows the raw DMX value going out to verify is is indeed at 255.
3. If the values isn’t at 255, find if there is an inhibitor of some sort or a playback at higher priority limiting the range.
4. Related to the previous, select the light in question and use the console’s tools to show how many faders are giving commands to it.
5. Verify the correct Linking Key and Port from the Stardust is set.
6. Switch the patch to another fixture and test again.
7. Switch the fixture to another address and test again.
8. Pair a wireless receiver to the same port on the Stardust and plug my DMXCat in to make sure the fixture is receiving the value I think I’m sending.
9. If you don’t have a spare receiver but do have a computer (and you always should for troubleshooting), use sACNView for sACN or something like Artnetnominator for Artnet to check that universe across the network.
10. Test to see if your meter is functioning correctly by checking another fixture type set to 10k.
11. Double check the profile itself and make sure that you have the full range set up correctly in the profile.  Meaning- that there is a full range of 0 to 255 in the profile for an 8 bit CCT address.
12. When all else fails, take the fixture and put it in manual mode and set it to 10k and meter it.

This is not a comprehensive list, but hopefully you can see the approach of systematically trying to see where in the system a thing is going wrong.  For even a simple light to work on set, there really are a large amount of things that all need to agree.  Some of the key concepts that inform that list above are:

1. The profile and address matching between the board and fixture is the most likely problem.
2. If I’ve not used the profile before, the profile itself comes into question.
3. Picturing the networking your head, there is the console, the network (including cables), and the node.  There could also be DMX lines out from the node.  Every item here is suspect now.  So you need to test everything at either end and each junction.
4. If the light is a trusted brand, and I’ve controlled it before, then the light itself being borked will usually occur to me last.  Unless the problem is something consistent with damage- missing pixels, strobing, a variety of colors across the fixture.  
5. Wireless is it’s own set of issues, but usually shows up more like “The light isn’t responding” or “The light just dipped out or flashed up”.  I’ve not yet seen an issue with wireless that limited a CCT range, which I would file under the category “limited or untrustworthy DMX values across a network”.
6. Equally as unlikely (but definitely possible) is the light meter itself being borked.  So if my eye tells me the light is matching another source at 10k (or whatever), then I’d use a second  meter to rule that out.  

I believe I’ve gone over this in the past, but there are a few tools I never show up to work without.  They are:

1. A DMXCat.  Now also a DMXCat-E.  Invaluable for verifying what is happening at the far end of the data chain.
2. A laptop with sACNView and Artnetnominator installed.  Both of these apps not only show you what values are on a network, but what IP is sending them.  Also- the computer can be used to ping an IP address.
3. A laptop with Multicaster II installed for checking if my network is having a multicast-related issue.
4. A light meter of my own.
5. A backup node.
6. A phone or tablet with CRMX toolbox 1 and 2 installed.  Also the dreaded Astera app.
7. An ART 7 to go with the Astera app.

A recent lesson a friend just shared with me: Once you identify the problem- if it is the light and the light is part of the Gaffer’s gear- report the problem only to them or the BB.  Optics are unfortunately important in our business, and you don’t want to be the one framing bad optics on your leader.

Troubleshooting for most people is a life long pursuit that takes a long time to start to show results.  But I hope in some way I’ve been able to show you some logic and tools to get you started or get you further down the road.  Feel free to point out other things you would test for or tools you don’t leave the house without and mention them in the comments.  I’m always trying to learn more.

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Mark LaPierre is a programmer in film and television based out of Albuquerque.  He grew up in live entertainment and has been a designer/programmer for musicals, concert dance, live music, circus and corporate.  Mark is a proud member of IATSE, an ETC Eos trainer and an enthusiastic trainer of many other platforms and subjects.  He offers Zoom console training as well as in person.  If you enjoy his content, please consider commenting on his posts on the website to appease the Algorithm.  

Photo by Claudio Schwarz on Unsplash