Tech-Tips
Troubleshooting Part One: Analyze
Troubleshooting
Electrical v.s. Electronic
Finding & Verifying Buried, Mislabeled, or Unlabeled Cable Runs
#Troubleshooting Part One: Analyze
When troubleshooting a system, evaluation and analysis of the situation are critical. Before touching ANYTHING, first gather all of the relevant information in order to make an educated decision about how to proceed through the other four steps of the troubleshooting process. For example, if your car didn’t start you wouldn’t begin your troubleshooting by checking the tire pressure. For the same reasons it is important to understand the system you are working on as well as the true nature of the problem you are attempting to repair before jumping into the later stages of the process. By spending a little extra time at the beginning, you will increase the efficiency and accuracy with which you can complete steps 2-5 as well as save tons of time and headaches in the end.
As you head out on the road of gathering information during the analysis step, the first stop on your route should always be the client. (Btw, when I say client, I mean anyone living under the roof of, or with regular access to, the residence and system you are working on) By spending the time to conduct a thorough interview with the individuals experiencing the problem, you can gain valuable insights into what may or may not be wrong. A client who states, “My system doesn’t work” has not provided any information that can be used to identify the problem they are experiencing. It is up to you to ask additional questions in order to fully define and understand the true nature of the issue that needs to be resolved.
Sample Interview Questions:
• When did the problem first begin?
• Has anything in the system changed? (Devices or cables added, reconfigured, or removed)
• When does the problem normally occur? (Time of day)
• What exactly is the system doing or not doing?
• What other equipment is in use at the same time?
• What exactly have you experienced?
• Have you noticed any pattern in the problem?
• Have you smelled any unusual smells or heard any unusual noises when the problem occurred?
• What is different about the circumstances when this problem occurs and when it does not?
• How long has this problem been occurring?
• When the problem occurs, how long does it last?
• Has the problem increased in frequency or duration?
• Did the problem begin during a lightning storm or power outage?
• Did the problem manifest itself all at once or did it occur over time?
• Can the symptom be reproduced?
Once you have a clear understanding of the problem, it is time to observe and analyze the system itself. Review all available system documentation (wiring diagrams, blue prints, device manuals, etc…) and compare the system design documents to the actual system implementation. In the event that no documentation exists, begin creating your own.
As you continue to assess the situation, observe and document the cabling paths and connections, device configurations, environmental conditions, power connections, and anything else that may have an effect on the system performance.
Common Observations:
• Do you feel any heat or vibration in the equipment?
• Do you smell smoke or burning insulation?
• Do you see any flickers in the lighting or brightness of the equipment?
• Do you see any scorch marks or discolored areas on any cords or cabinets and housing?
• Do you hear any unusual system noises, like rattles, whines, or whistling?
Once the data gathering process is complete, it is necessary to analyze the results and document all of the known possible causes for the symptoms. By theorizing about the possible causes for the system failure, a more efficient diagnostic procedure can be chosen. We will discuss this in detail during the third installment of this series - Troubleshooting Step 2: Diagnose.
#Troubleshooting
I often marvel at the inefficiency of many installers within this industry when they are faced with troubleshooting a problematic system. In an all too common scenario, I have witnessed said installers simply begin removing devices or cables (from the middle of a signal path I might add) without stopping to actually evaluate the situation at hand. Such haphazard attempts to correct a symptom they have not even taken the time to understand, usually result in huge amounts of wasted time, an inaccurate diagnosis, and the extra expense of replacing devices and cables that were never defective. In the best case, one may stumble upon a workaround (more on this to come during part 5 of the discussion) that corrects the symptom temporarily, but inevitably leads to a callback sometime in the not too distant future.
These ineffective troubleshooting procedures are, one of the most obvious indicators of the difference between an installer and a technician. By my own personal definition, an installer is someone who understands the system they are working on in the most basic way possible and has the ability to follow direction and plug one device into another. A technician on the other hand, has an in depth understanding of how each device fits into the whole of the system, as well as the requisite knowledge of fundamental electrical theory and its application to the work we perform in this industry every day. A true technician understands that troubleshooting is a process and not simply a guessing game to be played with the company’s money. Troubleshooting is, by definition, the use of a logical, systematic process to efficiently and accurately diagnose and repair electronic system failures.
Troubleshooting, like most other forms of problem solving, may have more than one path that can lead to a correct solution. For this reason, it is paramount during the troubleshooting process to stay organized, think logically, and be patient.
It is critical to not get upset when things go wrong, because with electronics (or anything with moving parts) something will eventually go wrong. More often than not there will be struggles and frustrations during the course of a project, and accepting this fact and working through unforeseen obstacles methodically and objectively will increase the likelihood of a successful outcome.
Troubleshooting can be a very time consuming and costly process. For this reason, it is highly recommended that integrators PREQUALIFY systems prior to installation in the field. By prequalifying the entire system exactly as it will be installed in the customer’s home, technicians will likely uncover any unknown variables (i.e. device interoperability issues), design flaws, or malfunctioning equipment problems before heading to the job site. Once a system has been installed, it becomes more difficult to diagnose and problem solve as well as much more likely the client may become upset. By bench testing the system in a controlled environment (what I like to call the advantage of “Panicking in Private”), it not only allows for much easier system diagnosis, but significantly simplifies the process of implementing a solution.
Proper troubleshooting should never include random assumptions of which part to replace or which cable to re-terminate. Technicians should establish and use a specific methodology with repeatable step by step procedures whenever faced with a situation requiring them to repair a broken system. This will increase the likelihood of correctly diagnosing and permanently repairing the problem, while also greatly increasing the accuracy and efficiency of the overall troubleshooting process. The CEDIA recommended process for troubleshooting can be outlined in five steps: Analyze, Diagnose, Repair, Verify, and Prevent. Stay Tuned for the next installments of the troubleshooting process.
# Electrical v.s. Electronic
During my time in the field as an Electronics Systems Technician, I dealt with electricity and residential electrical systems on a daily basis . However, I was never a licensed electrician and nowhere in my job description did it stipulate that I should be able to run romex cable, wire an electrical outlet, install a circuit breaker, or work on anything else within the home involving voltages above 90v. So for the first few months of my EST career, it never even occurred to me how much the performance of the equipment I was installing was reliant upon the quality of the electrical system it was being plugged into.
Of course it wasn’t long before I ran into some problems on a jobsite that I just could not seem to solve by troubleshooting the electronic equipment that had been installed. I was replacing
 interconnects, switching out devices, changing inputs and nothing seemed to correct the distortions in the video quality. (On a side note, the haphazard methods of troubleshooting described above left much to be desired in the way of both efficiency and effectiveness. Stay tuned for a series on proper troubleshooting techniques in the upcoming ESPA newsletters…)
After hours of pulling my hair out, I finally let go of my pride and called my boss for advice. He listened to my laundry list of attempted fixes and then told me to take a break and wait for him to come check it out. When he got to the house, he grabbed a simple AC outlet tester (pictured below) and walked right over to the equipment cabinet. He unplugged the gear, plugged in the tester, and within a matter of seconds diagnosed that the outlet was wired incorrectly, and was causing all of the symptoms I had observed.
It is important to remember that the high end electronic equipment we work with every day is designed to operate under very specific conditions and the performance of these devices can be easily compromised by a poor electrical system. After that job, I immediately went out and purchased my own outlet tester, and from then on, before I ever plugged in a piece of equipment I always tested the outlet I was plugging into first. I recommend you do the same.
#Working with a Client's Existing Equipment
How many times have you done work for a home owner that had some type of pre-existing electronic entertainment equipment? I cannot count the number of systems I worked on that involved existing, client owned equipment.
Scenarios I encountered included: clients that purchased one piece of equipment to be hooked up and integrated into a fully functioning system, ones that purchased an entirely new system but wanted to keep at least one piece of their old system and grandfather it into the new setup, and even occasions where the entire system the client owned was staying the same. But I was responsible to troubleshoot it because it wasn’t operating correctly or service/maintain/calibrate it in order to improve the overall client experience.
In any one of these situations, the first step in whatever you are doing as a technician, is to ensure that all of the devices are functioning correctly and verify that the settings in the device menus are adjusted properly to provide the best performance based on the connections being used and the overall capabilities of the system as a whole.
This brings me to the real nexus of today’s discussion. What happens if the manufacturer’s remote for the device you are attempting to verify has been lost/damaged (this is a VERY common occurrence) or simply doesn’t work anymore?
You cannot always access device setup menus from the front panel of a piece of equipment, and even if you can get into the setup menus from the buttons on the device itself, using these is often a very cumbersome and inefficient way to make changes.
Also, programmable remotes designed with user friendly interfaces will typically NOT include buttons to give the client access to these setup menus, so even if you are returning to a home your own company performed the install for and you know there is an existing universal remote, this may not offer a solution to your problem.
It is for these reasons that I highly recommend all technicians carry an inexpensive laptop and basic programmable remote that can be used as an IR command database on their van at all times. That way, even if a remote is missing or damaged, you have access to a HUGE database of codes from the remote manufacturer’s software and can more than likely find the correct ones for the device you are working on.
Then it’s simply a matter of zapping them to the programmable remote and using it to make the necessary changes in the system setup menus. If you want to take the efficiency one step further, identify the brand and model of every device in the system prior to leaving the shop (this is something you should be doing anyway) and zap the codes for those devices to the remote before you even step foot outside the office (**Caution** it is still recommended to carry a laptop with you in this circumstance due to the percentage of uncertainty that the code sets you choose before getting to the jobsite will work with the device you are trying to control prior to testing them).
#Solving Ground Loop Problems
Have you ever had an install where the subwoofer was giving off a low frequency hum even though there was no sound playing? Or hooked up a TV and there were lines rolling through the picture? Both of these symptoms (audible low frequency hum or visible “hum bars”) are usually caused by what is called a Ground Loop.
Ground Loops are created when two points in an electrical system that should have the same potential to ground (i.e. 0O) actually have different potentials to ground. Most commonly in our industry, this occurs when you have multiple pieces of A/V equipment that are interconnected with each other but are hooked up to two different house electrical outlets thus creating a ground loop.
The easiest way to troubleshoot this problem is by inserting a Ground Lift Adapter (also known as a three prong to two prong adapter) like the one pictured below, in between the piece of equipment exhibiting the symptom and the wall outlet. If the “hum” goes away you have confirmed that it is indeed a ground loop that is causing the symptom.
However, it is
EXTREMELY IMPORTANT TO REMEMBER NEVER TO LEAVE A GROUND LIFT ADAPTER IN A SYSTEM AS A SOLUTION!!!! Leaving a ground lift adapter in a customer’s home is against fire and safety codes and should never be used as a solution to a ground loop problem. The proper way to fix a ground loop without rewiring the house electrical system, is by installing an Isolation Transformer (example below) that will enable the equipment to stay grounded while eliminating the difference in potential to ground.
#Finding & Verifying Buried, Mislabeled, or Unlabeled Cable Runs
For anyone that has ever found themselves trying to identify the location of a buried speaker cable before cutting into a customer’s wall or verify that they have selected the correct cable from a bundle of hundreds before making connections in the structured wiring panel, here are a couple quick tips that may make your life a lot easier.
We all know a tone generator and inductive noise amplifier (aka toner and wand) are extremely handy tools to use in these situations, but sometimes (especially with longer cable runs or double drywall) it can be difficult to hear the tone being generated through the cable. By connecting one of the leads from the tone generator to the house ground and the other to the cable you want to find, you can amplify the signal and make it substantially easier to hear.
Another problem that can occur when you are sending a signal through one cable that is part of a large bundle. The tone can be induced into other cables in the bundle, making it tough to discern which cable is the one you want.
In order to be sure you have identified the correct cable, make sure the tone generator leads are connected to two of the wires within the cable (Example: the red and black speaker wires of a four conductor speaker cable or the blue and blue/white wires of a cat5 cable) and then, on the other end of the cable, strip back the jacket and touch the same two conductors together while listening to the inductive amplifier. If you hear the tone drop out, you have found the correct cable, if however, you touch the two conductors together and the tone stays, you’ll have to go back to the bundle and do some more searching.
#Let's Talk Tools
If there’s one thing any veteran field technician knows, it’s how to take care of his tools. When working as a technician in this industry, your tools are your meal ticket, so it is highly important that you take good care of them.
The first step to taking care of your tools is quite simple… DON’T LOSE THEM! The total cost of a lost tool is much higher than the obvious money you will have to spend out of pocket to replace it.
If you lose a tool on a jobsite, you may not even realize it’s lost until you go to use it again on another jobsite. This means that you will have to leave the jobsite to go purchase the tool before completing the project. Therefore, in addition to the outright replacement cost, the total cost of a lost tool includes: lost time on the jobsite, gas to and from the hardware store, increased client frustrations, and an unhappy employer.
To avoid losing tools, it is imperative that you keep your tools well organized. To accomplish this, invest in a quality tool bag (like the example pictured) instead of a simple tool box where your tools will typically get thrown in and piled on top of each other.
Tool bags are designed with multiple pockets and sectionals that can be used to organize all of your hand tools as well as test instruments and useful hardware. By organizing your tools into specific pockets within the tool bag, it becomes very easy to visually scan your tools and take a mental inventory in a matter of seconds.
Keep your money in your pocket, your customers satisfied, and your boss happy by investing in a tool bag and avoiding the loss of your tools.
#IR Remote Troubleshooting
How many times have you tried troubleshooting an IR remote program that isn’t working? Is it the program that’s bad or is the remote itself not working? Wouldn’t it be nice if you could simply look at the remote and see if it was actually sending a signal? Well pull out your smart phone and take a tip from a pro that will save you a lot of time and headaches.
The human eye cannot distinguish infrared light and therefore we cannot see if a remote is sending a signal just by looking at it. However, cameras are designed to pick up a wider frequency range of light waves than the human eye and can help verify whether or not an IR command is being sent.
Most cell phones these days have cameras. So the next time you need to verify IR functionality simply pull out your phone, turn on the camera, and look at remote output through the screen on your phone. If it flashes, you know there’s some type of signal being sent.
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