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
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
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
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
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
Ever wondered how L1 and L2 in a 240 VAC circuit have a voltage difference of 240 VAC? Or what people mean when they say that L1 and L2 are 180 degrees out of phase? And what exactly do we mean when we say "voltage difference" anyway?
We cover all these topics in this short 6-minute excerpt from one of our many in-depth technical webinar recordings. If you've ever been mystified by the inner workings of standard, split-phase household power, look no further! Give this a watch and be enlight
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
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
You're investigating a refrigerator that's not cooling properly, and you see the following bits of evidence:
Two questions for you to answer:
What (if anything) does the rime ice on the evaporator tell you?
The source of the problem with this refrigerator is present in one of these photos. What is it?
Let us know your answers in the comments, and we'll let you know if you're right!
Want to troubleshoot refrigeration problems like this (and much m
Specs are essential for troubleshooting. After all, to test a hypothesis, you need to make electrical tests, and to make electrical tests, you need to know what your expected readings are. However, manufacturers don't always give you everything written out. What do you do if you need to make an amp measurement, but the manufacturer only gives you watts? That's exactly the question we're going to answer in this excerpt from one of our many in-depth technical webinar recordings.
Say you're working on the cooktop of a Frigidaire gas range, and after chasing some wires, you find that this component is in the circuit, right after the power comes in from the outlet:
The label calls it a "signal transformer", but what is the point of this device, exactly? Well, as with most circuit mysteries, the schematic will give us some more insight...
How odd -- a transformer that, seemingly, doesn't do anything. You have 120 VAC going to the primary, and 120 VAC c
Jazz boards are a classic common-fail item in Whirlpool refrigerators, so important to know the right way to go about troubleshooting them. The good news is that they operate on the same principles that all control boards do, so if you know your basic electricity and troubleshooting principles, making big money off of these is a snap.
This is exactly the kind of stuff we teach in our Core Appliance Repair Training Course over at the Master Samurai Tech Academy. If you want a taste of that g
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
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
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.
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
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
Manufacturers do sometimes help us techs out -- Samsung has been putting on training sessions pretty regularly both for their own models, and for Dacor-branded models as well (Samsung acquired Dacor a few years back, for those who don't know). While a lot of how we troubleshoot is by understanding the principles that are common to all appliances, you always need a bit of info specific to the appliance you're working on. In particular, information about the exact implementation of the technology
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'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
We drop a lot of pearls of wisdom in our live technical training webinars, and I wanted to make one particular pearl available to all. In this short excerpt from one of our many webinar recordings, we cover what you need to know about electricity and voltage in order to make a meaningful and useful voltage measurement -- all in the context of a real troubleshooting scenario.
Topics covered include:
What is voltage?
How do you choose a voltage reference?
What is LoZ?
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
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
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
Many techs are intimidated when they first look at a schematic -- but you don't have to be! You can make sense of any schematic, even one with multiple control boards, by following some simple troubleshooting principles. And that's what we're going to show you in this short clip from one of our many technical training webinar recordings.
In it, we'll use a real-world tech sheet to demonstrate some of these principles, such as:
Identifying the control boards
Identifying the b