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
We encounter diodes in a variety of situations, such as in certain refrigerator water valve configurations. If you want to be able to properly troubleshoot these setups, you need to understand the underlying technology of diodes. How doe they affect the circuit around them? And how do you test them?
These are the questions that we answer for you in this short video introduction to diodes. In just 6 minutes, you'll learn about how they work and how to properly test them. Plus, you'll learn a
Whether you were aware of them or not, Hall effect sensors are everywhere. Any time you see a motor on an appliance with any kind of RPM feedback or speed signal, there's a Hall sensor on that motor. As with any ubiquitous appliance technology, it's important for us techs to know how they work. A deeper understanding of the technology means a deeper understanding of how to troubleshoot it.
So: what is a Hall sensor, and how does it work? These are semiconductor devices, so as with most elec
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
Here's a weird one for you: how does this dryer run with the neutral wire of the pigtail completely disconnected? To find out, watch this short, 7-minute excerpt from one of our many full-length technical training webinar recordings.
In this video, you'll learn the answer to questions like:
What is the difference between 3 and 4 wire dryer cords?
Why should neutral and ground be separated?
Why is the dryer able to run without neutral connected?
Give it a watch a
We've got a tricky one for you today: a Frigidaire-built Kenmore electric dryer that only runs on heat cycles. If you set it to a timed or auto dry, it runs just fine. But set it to air fluff, and you get nada -- no motor rotation, no nothin'. Sounds like a bad timer, right? That was our first thought, too. But like any good tech should, we covered all of our bases before jumping to conclusions, and what we found was much more interesting...
We'll start by analyzing the circuit of the motor
Reading schematics is an essential part of troubleshooting, but it's not always clear how to break down a circuit into understandable bits. Is there an easy rule of thumb for identifying what component does what and how to go about testing it?
In this excerpt from one of our many full-length technical training webinar recordings, you'll learn exactly that! In addition, we'll show you how to break down a seemingly tangled schematic and identify loads in series vs. loads in parallel -- all in
By now, most of us are used to variable speed drive motor systems in appliances. The control board sends a PWM signal to an inverter, which tells the inverter how fast to run the BLDC motor.
While this is the type of inverter that's been used in appliances for years now, it's not the only kind of inverter out there. In fact, another type of inverter is starting to crop up in the appliance world, and it may very well become the norm for some applications. It's called a drop-in inverter, and
The temperature sensors used in ovens, which are devices called RTDs, don't vary too much between brands and models. There's something of an industry standard for RTD specs that you can generally rely on, even when you aren't given the specs explicitly.
However, Frigidaire has left a booby trap in the form of an RTD with unique specs in some of their ovens. What's more, this difference isn't even properly reflected in some of their tech sheets. They've got incorrect specs!
Want to know
"Ohms lie." It's become a popular phrase in the tech community, but what does it actually mean? Should you never do an ohms measurement? Are they completely worthless? Or is this phrase just another example of tech mythology?
The answer is more complicated than any of that. Let's run through a quick example to demonstrate. This is an old-skool Whirlpool gas dryer, just like they were cranking out left and right in the good old days.
Now, our scenario is a simple one: when we run
In this excerpt from one of the many technical training webinar recordings available to our members, we cover two tricky areas that have tripped up many a tech: deciphering an unclear schematic, and decoding a convoluted customer problem description. Both of these are essential skills for any tech, since if you mess up either of these steps, the entire rest of your troubleshooting will be thrown out of whack.
The troubleshooting framework that we're using in this video is our patented Ten-S
Some techs long for the "good old days" of mechanical controls, when troubleshooting appliances was supposedly simpler. But the universal use of electronic controls nowadays actually provides many troubleshooting benefits -- in particular in the form of error codes and diagnostic modes.
The purpose of error codes is for the control to tell you its best guess of what's wrong, based on the algorithms programmed into it by the engineers. Note that the engineers' best guess is sometimes a very
Special guest presenter Mark Williams will show you how easy it is to diagnose temperature problems in the newer electronically-controlled refrigerators and how to do it right the first time.
We'll show you examples from Samsung, LG, GE, Whirlpool, and Electrolux. You'll see that they all work the same way.
You'll also see how to accurately test thermistors from the computer control board and you’ll learn the difference between resistance and voltage drop when it comes to testing the
Reading timer charts may just seem like an old-skool skill for a bygone era of appliances, but there are still plenty of these old workhorses around that need troubleshooting. Plus, analyzing these circuits teaches you a lot of schematic mojo that is useful in all areas of appliance repair.
In our latest Live Dojo workshop, we worked through how to read this timer chart and schematic in harmony with each other. You can't understand the schematic without the timer chart, and vice versa. Topi
Sometimes, manufacturers don't write out schematics as clearly as they should. In cases like this Frigidaire cooktop, the way that the relays for the simmer function are drawn is downright obtuse.
In our latest workshop webinar, we broke down the function of this circuit and really understand how it works, bringing our electrical and technical know-how to bear to make logical deductions about the circuit.
Did you miss the original webinar and want to watch this webinar recording? Click
Imagine you're in this situation: you're trying to do some ohms testing on the heater of an LG electric dryer. You're reading 21 ohms across a single coil, and 42 ohms through both coils. But when you look at the spec on the schematic, you're seeing almost exactly half that:
Weird. Maybe the heater is out of spec, but that's a weird discrepancy. And it's bizarre that we're reading double the specs given.
Can we get a second opinion? You look elsewhere in the manual, and you find
We had a great webinar this past Sunday all about troubleshooting a Thermador wall oven with a cooling fan that wouldn't run. Lots of vital tech know-how covered in this one, like how to structure your troubleshooting flow, identify loads and switches on schematics, and perform useful and meaningful tests that will lead you to the correct solution.
In this short excerpt from the recording of that webinar, we talk about using the schematic to identify EEPs for your testing -- no unnecessary
When it comes to troubleshooting BLDC motors and inverters, there's usually a standard strategy. You check the input to the inverter (a good 120 VAC power supply and a PWM signal from the main control) and you make sure the motor windings are in spec and all the same resistance. But what about measuring the output of the inverter?
This is certainly possible to do, and it can be a useful measurement, especially in hairier inverter troubleshooting scenarios. But before we get into that, let's
Want to really put your technical know-how to the test? Well, have we got the webinar for you!
This one covers a whole potpourri of circuit puzzles and troubleshooting scenarios, including:
Some pop quizzes about series and parallel circuits
Diodes, how they work, and the surprisingly tricky situations that can arise because of them
Loads in series, how they work, and what they look like in a real refrigerator schematic
A real world troubleshooting scenario invo
Got a fun one for you today, pulled right from the annals of Appliantology. That's right -- a tech just like you encountered this whacky problem and figured it out.
Here's the weird scenario: several different loads aren't working on this Whirlpool-built Thermador refrigerator. The water and ice dispensers, the dispenser light, and the freezer light are all inop. Wow, four different loads all happened to fail at the same time! Crazy, right?
A lesser tech might have gone full PCM and st
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