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
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,
Loading down is a failure scenario unique to DC power supplies, and if you don't know what to look for, it can leave you scratching your head and eating some expensive parts. How do you identify that you have a potential loading down scenario, and what steps can you take to verify that? That's exactly what we cover in this Master Samurai Tech Workshop.
Topics covered include:
How DC power supplies work
How they affect the board's operation
What loading down is and how
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
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?
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
Take a look at this motor circuit:
Three different windings? Triacs in the circuit? A "sense resistor"? What's going on here?
As it turns out, there's nothing really new or different happening here. In fact, all we're looking at is a standard split-phase motor with two different start windings. One is the start winding when the motor functions as a drain pump, and the other is for when the motor functions as a wash pump.
Here's what the circuit looks like when the drain wind
Take a look at the circuit for this electric cooktop element. Notice anything odd about it?
Looks pretty straightforward, right? Well, it certainly is straightforward when the simmer switch isn't closed. Here's what the circuit looks like when it's not running on simmer.
L1 goes through the simmer select board and a temperature-controlled switch, and L2 goes through the relay board and a couple other switches. Standard stuff for one of these elements.
But what's going
How does a dryer dry without a vent? Why is there a sealed system in this dryer, just like what you would find in a refrigerator? How well does this model dry clothes compared to a conventional dryer?
All of those are questions we answer as we explore Whirlpool's hybrid heat pump dryer. In this thorough rundown of the machine's key systems and components, we cover topics such as:
The function of the sealed system in this heat pump dryer
How this dryer condenses moisture rathe
While all appliances use the same fundamental technology, their manufacturers often talk about them using different terms. Let's talk about DC power supplies and how not to get tripped up by the different terminology used there.
First off, the very basics. Just like in AC, any DC circuit needs two legs: the voltage supply, and the return. The return is called Ground in DC. Don't let that confuse you -- DC ground is NOT AC ground-- they are electrically distinct and separate. Ground is to DC
When you see a term like "FlowSense" in a service manual, don't immediately assume that you're dealing with some bizarre, new technology. 99% of the time, it's just a fancy brand name that the manufacturer slapped on a bit of simple tech that's been around for decades.
And that's what you're going to see in this video! in it, we show how "FlowSense" is just a fancy name for a single sensing line on the control board that detects the presence or absence of L2. Watch it now to learn exactly
When a control board doesn't seem to behave the way it's supposed to, does that mean it's always time to replace the board? How do you avoid the dreaded callbacks on service calls where you replaced the board because you had no idea what else to replace? Is there a way to reliably troubleshoot computer-controlled appliances and avoid guesswork when it comes to the control board?
Of course there is, and Team Samurai is going to show you how!
It all boils down to understanding how these
Our scenario today is a dryer that heats intermittently. Blitzing through the Ten-Step Tango, we select the heating element as our LOI.
But how do we test the heater's power supply? Do we have to start tearing things apart to do our tests?
If you've been around Appliantology long enough or taken our courses over at Master Samurai Tech, then you'll know that the answer is, of course, "no". Instead, we've just got to look at the schematic and pick some clever test points.
All
We've got dozens of hours of webinar recordings here at Appliantology covering all kinds of appliance repair troubleshooting strategies and technologies, ranging from the very advanced to the fundamental. This short excerpt from one of our many recordings covers the basic, but crucial concepts you must understand to troubleshoot an appliance with a control board -- even on seemingly "weird" brands like Samsung --including:
How to read and troubleshoot with board pinouts
How do DC
We techs should always be looking to sharpen our repair skills, and one of the best ways to do that is to learn from each other's experiences.
In this excerpt from a longer webinar, the Samurai walks through a Bosch dishwasher no heat problem that he encountered, working through his thought process and schematic analysis step by step. Watch it and learn a thing or two!
Want to watch the full webinar recording? Click below -- viewable only by premium members.
While we don't like to rely on ohms testing as appliance technicians, those tests have their place -- such as if you want to verify that a compressor's windings are in spec. But if you want to do an ohms test on a split-phase compressor's windings, you'll need to identify which of the three terminals on the compressor's casing corresponds to which winding.
To do so, you have to have a little bit of knowledge about how split-phase compressor windings are arranged, and what their specificatio
In this two-part Master Samurai Tech webinar series, we explore the nuances of sealed system diagnostics. Specifically, we're covering the nitty-gritty of applying our understanding of sealed system thermodynamics to real-world sealed system failures, such as refrigerant leaks, overcharges, and inefficient compressors.
Sealed System Diagnostics, Part 1
Sealed System Diagnostics, Part 2
Topics covered in the first part include:
Sealed system temperatures and pressure
Refrigeration is its own little world within appliance repair. The presence of a sealed system introduces all kinds of specific knowledge and skills you need to have to properly troubleshoot these machines, from thermodynamics to compressor technology to brazing. And that's not even mentioning the other systems, like airflow and control.
So how do you learn all this stuff? Well, if you want to troubleshoot refrigerators like a real tech, you'll need both brains-on and hands-on trainin
Take a look at this schematic, paying particular attention to the two circled relays.
What the relays actually do is pretty simple -- they switch L2 to the left and right burners on the cooktop. But slightly more perplexing is the question of how the relays close when those burners are turned on. We see the row of four burner switches along the bottom of the schematic above, but how do those switches cause those DLB relays to close?
A quick recap on how relays work: a relay is an
The very first step in troubleshooting a broken appliance happens long before the tech sets foot in the customer's home. In fact, it can happen even before the tech knows about the service call. We're talking about formulating a problem statement.
What I mean by a problem statement is very specific. A valid problem statement answers these two questions: "What is the appliance not doing that it should be doing?" and/or "What is the appliance doing that it shouldn't be doing?" It doesn't go b
Ghost voltage has misled many a green tech during his troubleshooting. How are you supposed to interpret it when the VAC function of your meter tells you that you have 108 volts going to a load? Is your voltage supply bad? Or are you perhaps simply missing your Neutral?
That's where a loading meter comes to the rescue. By actually putting a load on a circuit, the loading meter shows if there really is the difference in voltage between those two points required for current to flow.
No N
Gas burners are a whole little microcosm within appliances with some interesting technology that we don't see much elsewhere. In this webinar recording, we cover how to troubleshoot various cooktop ignition systems, covering topics such as:
DSI systems
Single-point ignition
Reignition systems
Continual sparking after a flame is established
Applying the Ten-Step Tango to real-world problems
...and more!
Click below to check out this webinar record
At ASTI 2025 in Orlando, FL, I had the honor of teaching a class on reading schematics and troubleshooting using Master Samurai Tech's patented Ten-Step Tango troubleshooting technique. During that class, we did diagnostic workshops on a number of different scenarios, all of which were taken from right here at Appliantology. For those of you who couldn't make it out for the convention, let's run through one of those scenarios here.
We'll be running through the steps of the Tango, but for th
As control boards, and especially multiple-board configurations, become more and more prevalent in appliances today, we need to keep our troubleshooting skills sharp and adapt. So what troubleshooting strategies should you apply when you're dealing with a computer board?
The good news is that you don't need to be a computer geek to work with boards. You just need a troubleshooting strategy for dealing with them, and you need to understand how they operate on a basic level. That's what the S
I just got back from this year's ASTI a few days ago -- a somewhat unique one, styled as "ASTI Lite". While the conference was shorter than usual, I still had a great time meeting many of the fine techs who hang out here at Appliantology and/or train with us at Master Samurai Tech. Looking forward to seeing all of you again at the next ASTI this January!
When I wasn't putting faces to Appliantology usernames, I was attending the training classes put on by various manufacturers. Ever mindful
