We techs rely on accurate technical documentation to do our jobs. You can't make a troubleshooting plan or make meaningful electrical measurements without a good schematic. But what do you do when your technical info contradicts itself?
Let's take a look at this Whirlpool refrigerator, specifically focusing on the evaporator fan. Here it is on the schematic, marked up for your viewing pleasure:
Looks like a standard 120 VAC fan motor. But now, let's take a look at some of the wri
There's a very common configuration of valves that are used in refrigerators with ice makers and dispensers -- so common that every tech should be very familiar with how it works and what terms are used to refer to it. You can't troubleshoot what you don't understand!
We'll use a GE refrigerator as our example, but this same system is used across almost all refrigerators with water supplies. Here's a snippet from a GE manual:
All this is saying is that you have three valves in th
The technical side of the service call is generally what gets the spotlight, but what you do before, after, and during the call is just as important to your profitability -- and I'm not just talking about soft skills. The way you organize your thought process and go about your troubleshoot is vital to service call success. And that's exactly what we talk about in this short excerpt from one of our many technical training webinar recordings.
Topics covered include:
How to run a servi
Join me on another short troubleshooting journey -- this one taken from a real tech's experience that he posted on Appliantology.
You're troubleshooting a Samsung dryer that won't start-- the control panel will let you select a cycle, but it won't actually run if you press the start button. But the real head-scratcher is that, despite not being able to start a cycle, the machine always runs when the door is closed.
Sounds tricky, but as you'll see, the troubleshoot is pretty simple if
Let's look at a seemingly simple load that has more going on than you would think: a multi-speed hood fan in a microwave. The questions we want to answer are: how many speeds does this fan have and how does it achieve those speeds?
If you look at the spec block for the motor, the answer to the first question seems easy -- looks like it's a simple two-speed motor.
But when you look elsewhere in the tech sheet, you find this voltage table that seems to state you have four speeds. (
Here's our scenario: you're working on a Samsung WA50K8600AW washer that won't advance in the cycle. Error codes and test modes aren't telling you anything useful, and the control doesn't even seem to be trying to advance the cycle. You've checked the air tube connected to the pressure sensor, too, and everything is clear there.
What can you do here? Do you just call it a bad board and move on?
Let's see if there's a smarter test we can do on this one. What if we could test the signal
Ever wondered what the inside of a gas dryer valve looks like? And what's the purpose of having two separate valves in one component? What about those mysterious "safety" and "booster" coils?
All of these questions are answered in this short excerpt from one of our many in-depth technical training webinar recordings. Give it a watch and, if you want to see more, click here to watch the full recording. This and dozens hours more of technical education are available only to our premium member
We've got a toughie for you to figure out today. The tech in this scenario has been out on this dryer multiple times now, and the problem just won't go away. The heating element keeps going open, and the timer motor keeps stalling and not completing cycles. He's verified a good 240 VAC power supply to the timer and replaced both parts multiple times, but the problem keeps recurring every few months. What gives?
Let's board the train away from PCM-Land and use one of our foundational trouble
Here's the situation: our tech has a Whirlpool dishwasher that does everything normally, except the wash motor simply won't run.
He's done his due diligence and checked for voltage to the motor -- with a LoZ meter, even! -- and what he's finding is puzzling. It looks like the voltage is jumping around from 0 to 120 VAC erratically. What does this mean? Could it be a bad board?
As with all good troubleshoots, let's start with the schematic. Here's just the motor circuit:
Now,
Here's a scenario taken right from the trials and tribulations of an Appliantology tech: you're troubleshooting a no heat complaint on a GE electric dryer. You start your troubleshooting with the heating circuit, and your findings are puzzling: there are 120 volts on either side of the heater with respect to neutral, but when you do a voltage reading across the heater, you get some weird amount like 80 volts. What gives?
There are a couple of things going on here, and one is easily remedied
In this short, informative video, the Samurai walks through the steps of the patented Timer Chart Cha-Cha -- a system for reading and applying timer charts to schematics so that you can make sense of what's going on in the circuit. In just 2 minutes, you'll learn the steps of the Cha-Cha which empower you to troubleshoot timer-controlled circuits with ease.
Want to see the Timer Chart Cha-Cha in action and watch how it improves the troubleshooting process? Click here to watch the full webin
Everything runs on circuit boards these days, and wherever there are circuit boards, there are semiconductors. But what are semiconductors, exactly? How are they made, and what do they do?
These are exactly the questions we'll answer for you right now in this excerpt from one of our many on-demand technical training webinar recordings. In it, you'll learn the answer to questions like:
What are semiconductors?
What are they made of?
What is "doping" in semiconductors?
Got a fun exercise for you today: let's use our electrical and schematic know-how to figure out how a circuit works in a schematic that leaves out a lot of useful labelling.
The circuit we're interested in is the one labelled Door safety interlock.
Based on its name and its context within the schematic -- it gates Line to a number of loads elsewhere in the appliance -- this circuit contains the door switch and the door lock. But how exactly does it work? We can assume that the sw
Many appliance repair techs are intimidated when it comes to troubleshooting control boards. When we talk about "control boards," we're really talking about a single-board computer. After all, we are talking about computers here -- computers that just so happen to run appliances. Samsung is especially famous among techs for being “too electronic” or using too many control boards. Many techs will install a replacement control board from Samsung without running a single test, just to avoid the hea
Imagine you're out on a call, and you run into this:
As the picture says, the dryer runs like this. And even weirder, when you correct the wiring, it stops running.
Take a minute to think, then see if you can answer this pop quiz:
1. How does the dryer run in this configuration?
2. What's wrong about the wiring in this configuration?
3. Why does it stop working when you correct the wiring?
4. What one test could you do that would prove your hypothesis about th
Reliable income is something all techs want to achieve. But to have consistent profits, you have to perform consistently on service calls. While we all might like to think of ourselves as repair cowboys who can head out on every job half-cocked and still get it fixed right, that's just not reality. The way to achieve the most consistency possible on service calls is by using systems.
A system is coherent set of standard operating procedures (SOPs) designed to achieve a specific objective. I
We've all changed countless ignitors in gas ovens, and any tech worth his salt knows that the definitive way to detect a failed ignitor is with a current measurement. But why does low current through the ignitor cause ignition to fail? Where does that current spec come from?
In this short excerpt from one of our many technical webinars, the Samurai explains the mechanism behind how these gas valves work. Not only will it give you a clear idea of the technology behind these common parts, but
Most of you have probably heard about loading down before -- when one failed DC component causes a ripple effect that keeps other DC components from functioning properly until the failed component is removed. But what does that actually look like in practice? And how do you go about troubleshooting it?
To answer these questions, let's take a look at a straightforward, real-world example of loading down (taken straight from this topic at Appliantology).
@marshall450 ran into what seemed
We're all familiar with how thermistors work: their resistance varies with temperature, which in turn varies the voltage drop across them. The control board then reads that voltage drop and determines the sensed temperature based on that.
But those with a bit of basic electricity knowledge might scratch their heads a bit if they think about this. Thermistors are almost always drawn on schematics such that they aren't in series with anything else -- it gets its 5 VDC supply and DC ground dir
Here's the problem scenario:
The customer's refrigerator has stopped running. You take a look at the start device, and it's completely burnt out -- enough so that you can see that the plastic housing has melted. You swap it out for a new start device and...
Still nothing. In fact, a quick voltage measurement shows that the control board isn't sending voltage to the compressor. Now the board needs to be replaced, too.
So what happened here? Did the start device just short out and t
How would you go about troubleshooting the valves?
As always, we should start with a load analysis on your load (or in this case, loads) of interest. That means identifying how each valve gets line and neutral. (The wire marked with a blue N connects directly to neutral).
You should immediately see that something is off. How do the IM and water valves get neutral?
The answer is that someone over at Whirlpool made a whoopsie when drawing this schematic. There should be a line
I've got another scenario for you, taken right from the trials and tribulations of an Appliantology tech. Here's the situation: you're working on a top-load washer, and whenever you try to run a cycle, the tub doesn't move and the motor just hums.
Right away, we have a decision to make: do we go ahead and tear apart the machine to take a look at the wash motor? After all, there are a number of mechanical failures that could cause these symptoms. Maybe we should just go ahead and get our han
Didn't make it to ASTI this year? You missed out on some great technical info!
But don't worry -- we took careful note of all the juicy tech tips being dropped by Samsung, Bosch, and Whirlpool in their technical training and showcased them for your benefit in this latest webinar recording. Give it a watch to get the inside scoop!
VFD (Variable Frequency Drive) systems have been around long enough now that most of us know the procedure for troubleshooting them. You have three main tests that you perform:
1. Check for the PWM (Pulse Width Modulated) signal from the main control to the inverter. This is a DC square wave data signal that alternates between 0-5 VDC. The inverter has to receive this signal from the main board in order for it to run the motor.
2. Check the 120 VAC input to the inverter board. This has
Self-clean sounds like a great idea, right? Just push a button and watch your oven burn away all that caked-on grease and charred food.It certainly makes for a good selling point. But is this no-hassle cleaning feature really all it's cracked up to be? And what is the best way for the customer to use it (if at all)?
First off: does it actually work? Can the oven clean itself just by getting really hot? Yes, definitely. Self-cleaning isn't just a gimmick, and when used properly, it does actu
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