Intention of the class: To give you the basic troubleshooting skills that enable you to be a rock-star problem solver at your events.
Basics to Troubleshooting
Troubleshooting can be a tricky thing to learn. But once you have a hold of the basics you will have no trouble finding and solving different problems throughout your system. But first we need to know the basic terminology in order to understand the basics. Let’s begin.
Basic terminology is critical for a DJ or anyone working in our field. Therefore allowing you to better describe a problem in your show report forms or to the On-call Manager, here are the following;
Mic (microphone) cable- this can be one of three different cables so naturally you might be confused. (Let’s differentiate) the three types are:
- An XLR cable
- A ¼ inch (or TRS)
- A ¼ inch to XLR (f).
An XLR is distinguished by a three pins at each end of the cable. An XLR cable is in fact a mic cable, but for us DJs it is a multi-tasker. And primarily used as a speaker cable for powered systems.
A ¼ inch cable is known by the diameter of the end of the cable (the end inserted into the device).
There are two types of ¼ inch cable.
- Mono/TS (or left side only)
- Stereo/TRS (left and right).
The TS stands for “tip & sleeve” in which you look at a ¼ inch cable you will only see one black line dividing the tip from the sleeve. Hence the name tip & sleeve, TS for short. This cable will be the most common for DJing purposes. As it is used to connect your wireless handheld mic receiver to your mixer.
The second ¼ inch cable is the TRS, TRS stands for Tip, Ring, & Sleeve. In short it is the same cable, but has a second black divider in the connector separating the tip from the ring, and the ring from the sleeve. As well as three wires in the cable versus the two wires in the TS cable (this cable is also called a BALANCED ¼ inch cable).
Finally a ¼ inch to XLR. This cable will be what you will frequently use as an actual mic cable. Even though you do have an XLR as a backup mic cable, so if there is an issue with any cables please specify which cable has the issue.
Be familiar with your gear. This is some of the gear you will encounter here at Pro Sound & Light Show.
- Mixer
- Laptop
- External Hard Drive
- CD Players
- Co-Pilot
- Par cans
- Effect Lights
- Mirror ball
- Props
- Wired Mics
- Wireless Mics
- Coffin
- Stands
- Light Bar
- Uplights
- Nimbus
- Monogram / Gobo Projector
Now that we have covered the terminology of troubleshooting let’s go over the principles of troubleshooting.
The main principle of troubleshooting is also the key to troubleshooting and if done correctly will lead you straight to the problem at hand….. Signal flow!
Signal Flow is the process or path that a sound or a signal follows in order to reach a given source.
example: Someone. talks to you from three feet away. The signal flow of this is their voice comes out of their mouth, travels through the air, to your ear where it is heard and processed by your brain.
Simple right!?! Well yes it is. The only thing that we are doing is adding several things to the process. Look at the diagram on the next page. The unpowered system is simple start with a source. CD player/cortex/laptop/mic receiver — now we know the end source (speakers) so let’s chart the signal flow.
– From the cd players to the mixer via RCA (red and white cables) the signal in the mixer flows through the board as follows; from the input -> the gain of the channel -> through the EQ -> to the fader (volume control) -> into the Main or Master. From the mixer into the amplifier via XLR cables, then from the amplifier to the speakers where it is heard by your ears.
For the active system is VERY similar but minus one piece of gear. the amplifier. The signal flow is as follows for an active system.
-From the cd players to the mixer via RCA (red and white cables) the signal in the mixer flows through the board as follows; from the input -> the gain of the channel -> through the EQ -> to the fader (volume control) -> into the Main or Master. From the mixer into the speakers via XLR cables where it is heard by your ears. Active speakers have the amplifier built into the speaker making it easier to setup and run.
Second and last principle is to replace the variables (cables) as you follow through the signal flow.
EXAMPLE: One of the two cd players will only play out of the left side. Where to start? With the obvious, is everything turned on? Are your volumes turned up? YES! (You have no idea how often it happens and how stupid you feel when it does happen) so move on to signal flow. Start with the RCA’s when you play the NON-working cd do you see that you are getting a signal to the mixer (yes or no). Yes, continue on with the flow. So check your gain on your mixer (check, your good). See if you are getting a signal to the master volume. Then move onto the XLR cables (you check these by seeing if you are getting a signal to your amplifier if so continue on with the flow). Check the power and volumes on the amp. (You may have a stupid moment in your head. IT’S OK!) So the amp checks out (only one step left to check) check connections on the cables from the amp to the speakers. See that they are plugged in correctly and fully plugged in. After checking the cables you find that the left speaker cable is not plugged in fully you push it in and TAH DA! It works problem solved.
When you know your gear, signal flow goes really fast. Fast enough that you can think and find the problem within 1-2 minutes. Then repair the problem within 1-2 minutes total down time 2-4 minutes! Sometimes the problem can be fixed during a song so there is NO down time, and no one knows. But if it does it’s not long till the party is hopping once again.
These are a few examples of troubleshooting, but with the knowledge of your gear and the terminology.
Dreaded troubleshooting is an easy task to conquered
Troubleshooting Procedure at a Live Show
Do a sound check as soon as possible once you are set up. This should be well in advance of the start time of the event. If you are not able to get sound, or the lights working, follow these steps:
- Verify everything is plugged in correctly and powered on, and that volume levels and gain dials are correct
- Make sure everything is running through the Furman power conditioner
- Verify that the mixer is getting audio signal
- If you can’t get music playing from the laptop, try talking on the microphone, or playing a CD, or plugging your phone into the mixer. This is to verify whether the problem is with the SOURCE, or with something in the setup.
- If the mixer is getting audio signal (the light is showing signal), then re-check the cables. Swapping cables as necessary.
- If swapping the cables doesn’t fix it, then plug your phone or a microphone directly into the speaker to verify that the speaker itself is working.
The purpose of troubleshooting is to logically find the problem, and then fix it. You can use a “Divide and Conquer” method to verify what is working and what is not.
If after 5 minutes of troubleshooting you are still unable to resolve the problem, then call the on-call manager and they will walk you through the process. If you have already identified the problem, the on-call manager will have you re-verify the issue. DO AS THE ON-CALL MANAGER ASKS YOU TO DO.
Very rarely will a troubleshooting problem arise during an event, this usually only occurs when something catastrophic happens. IE. A power surge, a breaker trips, a drunk guest unplugs a cord, etc. So it is important to get the troubles resolved beforehand, to give yourself a clear head to be calm and collected at the start of the event.