There are a lot of funky things going on on this Electrolux dishwasher schematic -- including normal-looking switches that are labelled "transistor switches". What does this label mean, exactly, and how does it affect our troubleshooting? That's what the Samurai breaks down in this short clip from a longer technical webinar recording.
Want to watch the full webinar? Click below to watch -- available only to premium members.
Be warned: this week's troubleshooting scenario is somewhat chilling...
...or maybe not, since the problem is that the ice dispenser isn't working. In fact, the entire fridge shuts down when the ice dispenser is activated. How can this be? Well, in this recording from one of our biweekly Live Dojo workshops, we go over the relatively simple cause to this strange issue.
Loading down is the culprit here. That's when a faulty load grounds out the control board's DC power supply, causing a
Long gone are the days when we techs had any excuse to be scared by names like LG or Samsung. Through information tools like Appliantology, we have access to all the technical docs we need to service these models. And anyone who has spent time examining the schematics and service manuals for Samsung appliances knows that there's nothing weird or proprietary going on here -- maybe a bit of Korenglish here and there, but how electricity works and the fundamental technology used in all appliances i
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
More than any other AC load, motors are all about amps.
What do I mean by that? When you have a motor that is misbehaving, the best, most informative electrical test you can do by far is amps. And one of the worst mistakes you could make is to just rely on ohms when testing a motor.
In this recording from one of our biweekly Live Dojo workshops, we go over several different aspects of troubleshooting motors.
Thermal controls are the first order of business. All AC motors have an i
Ever looked at a timing chart and been mystified by how to decipher it? Or maybe you're looking at the schematic, and you can't make heads or tails of which switch is supposed to be closed when during a cycle.
If timer charts have ever given you trouble, then this is the video for you. In less than 10 minutes, we'll show you how to read a timer chart, correlating it with the actual steps of the cycle, and then identifying how it relates to the state of the switches on the schematic. Give it
How do you put an ice maker that looks like this into a test harvest?
The tech sheet has this to say about starting a test:
That tracks with the old classic Whirlpool ice makers, but there's no T or H test terminals to be seen here. So what gives?
Well, it looks like there might be a test button here, if we look closely...
Turns out, that tech sheet is just outdated and flat-out wrong. You need to press this button twice within 3 seconds with a thin, pokey i
Here's the situation: the tech has a Maytag dishwasher with no lights, no life, no nothin'.
With a multimeter on LoZ, the tech has already checked the following with reference to ground. Here are his findings that he reported:
Seeing that there was a solid 120 volts to the board and no operation, the tech concluded (with the aid of a few ohm checks across the control board) that the board was the culprit. He replaced it, and...
Still nada.
How could such a seeming slam-dunk
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
The general rule for dryer vent airflow is that, if the airflow feels like a breath (even a strong one), then you have a problem. This rule of thumb will serve you well a lot of the time, but sometimes a "calibrated palm" just isn't enough. Sometimes, you need to get an actual measurement of the airflow so that you can compare it to the specifications.
What you really want to know is the volumetric flow rate of the dryer exhaust. That is, how much air it's pushing out over a particular peri
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
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
Refrigeration can seem a bit like magic -- how does a little bit of refrigerant being pushed around in some metal tubes somehow chill a freezer down to 0 degrees F? Well, it's not magic -- it's just physics. But granted, it's an aspect of physics that we don't often interact with in our daily lives, and it can be a bit unintuitive at first.
It all has to do with how a material can absorb heat without actually getting hotter. How does this happen? That's what we explain in this excerpt from
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. (
Ever wanted an in-depth explanation of how a split-phase motor gets going from a dead stop? Sure, most of us have a passing knowledge of what's going on. But do you really know what's happening on the electromagnetic level? What is this special "split-phase", anyway, and how do we quantify the way the magnetic fields interact?
These are exactly the questions we answer in this excerpt from one of our many full-length technical webinar recordings. Don't worry, we're not getting into any of th
In this short, easily-digestible technical workshop, we dive into some of the wacky things that can happen when a sloppy tech miswires a dryer terminal block. In fact, this dryer looks like it shouldn't be able to run -- the neutral wire isn't even connected! And yet it does run. How, you ask? That's exactly what you'll need to watch and find out.
This and our dozens of other technical training webinar recordings are only viewable by premium tech members at Appliantology.
Topics covere
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
We've got an interesting one for you today -- take a look at the "IDI Motor" in this schematic:
That's the ice dispenser auger motor in this fridge, and there are a couple interesting things to figure out about it. First, what's the deal with its power supply? If you look at the label on the motor, you'll notice that it says:
So that's a 120 VDC motor. How does that work?
A quick look through the documentation tells us that this motor is designed to run in two differen
Here's a GE microwave schematic. There's a lot of typical microwave stuff going on here, but we're going to focus in on one component today: the monitor switch.
What exactly is this switch's purpose, and how does it affect the circuit?
The purpose of the monitor switch is to act as a safety to prevent the magnetron from being energized while the door is open. The door latch and switches in microwaves are designed so that, if everything is working correctly, the monitor switch sho
Let's crack out our schematic-reading skills and take a look at a seemingly straightforward washer lid lock circuit.
Notice that, while they give us labels for the pins, that's basically all we've got as far as specs or info about the control board's algorithm. So if we want to figure out how this circuit works during operation, we'll have to crack out some Circuit Fu™. That means using both our understanding of electricity and our understanding of the intended function of a lid lock
What would happen if you took a 240 VAC outlet and swapped the terminals around? What effects might that have on the machine that's plugged into it?
That might just sound like an interesting thought question, but it's an issue that more than one tech here at Appliantology has had to deal with. So let's pull out a schematic as an example and start drawing some lines!
By the way, the process I'm going to walk you through is something any tech should be able to do: puzzle out how a circui
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
We're going to take a dive into what exactly is going on electrically with the high-voltage circuit in a microwave. We'll use this specific schematic as an example, but these principles apply generally.
Don't worry about most of the schematic. All that matters to us right now is the high-voltage section -- the transformer on the right side of the schematic and everything to its right.
If you're not familiar with how magnetrons work (or even what they are), then this circuit
These aren't your grandma's ignition systems -- these are systems that use a DSI (Direct Spark Ignition) board, and that means you've got algorithms involved.
If you want to troubleshoot a DSI system, you need to understand this algorithm -- it's how the board thinks. Is the DSI board not sending any voltage to the electrodes? Well, it might just be in lockout mode after a failed ignition, meaning the problem lies elsewhere than the board. You can't troubleshoot a system if you don't know h
A tech here in the Appliance Repair Tech Help forum recently ran into a conundrum: the range he was working on had an open bake valve, but there was also no voltage going to either the bake or the broil valve from the DSI control board. So is this just an issue with that open valve, or does the board need to be replaced as well?
To find our answer, let's first look at the schematic for this range.
Circled, from left to right, are the bake and broil relays, the bake and broil valv
.png.9012a87f3d9d47f1728530e9414b5964.png)
