How easy is it to repair a moving light or a piece of LED lighting equipment right down to the level of components on the PCB? There are easier repairs, and there are harder repairs, but is it worth your time?
A PCB is a Printed Circuit Board, or PC board, or PCB, is a non-conductive material with conductive lines printed or etched. Electronic components are mounted on the board and the traces connect the components together to form a working circuit or assembly.
Cost savings have never been more important to venues and production companies than in the current difficult situation the entertainment industry finds itself in. I’ve noticed a renewed interest in the repair of stage lighting equipment through training enquiries. This has ranged from questions about training in maintenance and servicing of moving lights, to helping a number of people diagnose and verify specific faults with individual components on a particular faulty PCB.
But before we start looking for that one tiny rogue component, what other options are there when you have a faulty piece of lighting gear such as a moving light or control console and you are tasked with getting it working again? You’ve moved beyond checking the lamp, fuse, the cable, and the mains supply. Let’s look at some bigger picture considerations.
Physically Damaged or Broken Gear
It could be a cracked casing, sheared fixing, or just a missing handle, but there are plenty of things that can be repaired at the simplest level like this – if you can get replacement parts. This kind of repair is outside of routine maintenance tasks such as replacing a lamp or an air filter, but often doesn’t require an in-depth knowledge of electronics or even fault diagnosis. It’s broken, it’s obvious and you just need to fit a new part. If the piece of equipment is out of production and parts are not available or expensive, then consider using parts taken from a donor.
The key skills needed here are to be able to identify a busted thing, and fit a not-busted one. There is also a practice related to this, which is to make a working item from several broken ones. Some people like to buy used gear packages of older broken fixtures and parts from a rental company with the idea getting themselves some moving lights on the cheap. Rental companies are not in the habit of selling off something that is still viable to them, which means that there is a lot of risk in buying used gear packages and hoping for the best.
Board or assembly swaps and similar fixes
This type of repair is very common for in-house technicians in a venue or hire company. The problem might be a faulty sensor, a ballast, a power supply, or a specific board that fulfills a particular function. The method of diagnosis is usually to identify the fault based on symptoms and narrow it down to a sub-part of the equipment. This is often verified to be the problem by way of substitution (swapping in a working part) and the repair made good by replacing the faulty assembly or PCB in its entirety. This working part can either be sourced new from the manufacturer or from a donor. One handy tool to have ready in this case is a known-good working part, for example a sensor or PCB taken from another fixture. However, be careful not to misdiagnose the source of the problem and unwittingly blow through a load of working parts by fitting them to a faulty piece of kit.
Key skills required are to understand roughly how the equipment functions, design and carry out a suitable test and verification to identify the faulty part, and fit a replacement. This is a common level for technicians that I work with and teach, particularly if they have some good overall technical understanding but perhaps are not yet confident in tackling specific pieces of equipment. This is often the case for moving lights and other complex gear.
Component level repair
This is a much less common skill, confined to a smaller number of specialists. There are reasons for this. First, the repair may end up being as simple as replacing a faulty component but identifying that component takes a high skill level and, more importantly, time. Time multiplied by a high skill level usually equals a high cost. This is why board or assembly swaps are the norm in the stage lighting business, similar to practices in the world of modern auto-repair. Second, compared to this potential cost of labor and those that come with the loss of utility, assemblies and PCBs are actually relatively cheap. Not taking the time to pin down an individual component but instead ripping out a whole PCB and swapping it for a working one is fast and gets the kit back up and running. Time spent waiting for parts deliveries is roughly the same but the diagnosis and fitting time is commonly much decreased.
So, why would you even try to repair at component and PCB level?
If you have time, but limited cash, then a “cheap” repair might be attractive. The idea that that a moving light that cost many thousands when new might be revived by a part that costs a few cents seems like a great deal. And it is. When that happens. If the replacement assembly is very costly or not available at all, this also makes component level repair attractive. There are certain parts that manufacturers sell as a complete unit, making each one quite expensive, when the problem you need to solve is limited to a small part of that assembly. PCB and Component Repair are not for everyone, but you will learn a lot more about the fixtures which will help better maintain other fixtures in the future.
About the Author
Bill Di Paolo has worked in live production for over 30 years, He is the owner and technical director of Entertainment Services, a production company based in upstate New York that handles lighting, audio and video for events of all sizes in the Northeast. If you have questions for Bill you may send them to him at firstname.lastname@example.org.