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
Come on a journey with me as we explore just how tangled your circuit analyses can get when you're confronted with conflicting information in a tech sheet.
Here's the Samsung washer schematic we're working with:
Nothing crazy here -- this is pretty standard stuff to see on a Samsung schematic. But when it gets weird is when you try to trace out the power supplies of various loads and board on the schematic with the help of the pinouts elsewhere in the same tech sheet.
Here's
Appliantology has always been a community built by techs, for techs, and one of the biggest ways the community grows is by simple word of mouth: techs telling other techs about all the awesome learning, discussions, and tomfoolery that goes on here.
To that end, we've got a great opportunity to show our appreciation and give a perk to techs who spread the good word of Appliantology. All site members, including Grasshoppers, can become Appliantology apostles. "Apostle" means "one sent out" u
We're so used to our fancy control boards and computer-controlled appliances that we sometimes forget how to troubleshoot old-skool circuits. While these circuits are generally pretty straightforward, the manufacturers employed some clever tricks that can mess with your head if you don't have a firm grasp of simple AC circuits.
Take the buzzer in this dryer as an example:
The Tan or Black side of the buzzer goes straight to neutral through that unlabeled switch beneath the temper
Just got back last week from ASTI 2020 in (not so sunny) Florida! Aside from helping man the Master Samurai Tech booth at the trade show, I attended as many of the manufacturer training sessions as I could. I figured some of the Appliantology Brethren would like to take a peek at my notes...
The first day and a half, I sat in on Liebherr, Samsung, and Whirlpool training. While these manufacturers all generally focus too much on monkey training (disassembly and other information you can easi
@LearningTech dropped a great tip in The Dojo a little while back: not all LG control boards can be updated after a universal compressor is installed. If you're planning on doing sealed system work on these machines, you're going to want to check the list below to see if your model's PCB can be updated. Otherwise, you might be in for a nasty surprise.
LearningTech also provided a handy image showing where you can find a PCB's manufacturing date:
Want to be in on cool tech t
Here's something you don't see every day: a gas range that is powered only by a 9 volt battery. Pretty nifty, huh? @Littletexan told us about his encounter with this one in this post from a couple weeks ago.
Let's look at some of the unique aspects of this model. We'll start, as always, with the schematic:
Well that's about as simple as it gets! All mechanical controls -- nothing too fancy going on here.
One thing I will point out is that, while the schematic seems to show a
The most basic circuit safety device that everyone is familiar with is the circuit breaker. All a breaker has to do is detect if the amperage in its circuit exceeds a certain threshold and open the circuit if it does. Simple and effective, but not every electrical hazard involves excessive current. In fact, having less current than you should can also indicate a serious safety issue. Enter the GFCI and the AFCI.
You might already be familiar with GFCIs (Ground Fault Circuit Interruptors) --
For those of us techs based in the States, it can be easy to think that electricity just "happens to exist" as our familiar 120/240 volt split-phase power. But that's only one of many forms that electrical power can take. It can come in a variety of voltages and phases, all depending on what standard a particular country or region decided upon.
Let's step through the most common of these. There are two that North American techs are likely to encounter: the typical 120/240 volt split-phase t
Samsung has developed something of a reputation in the tech community, and not necessarily the most flattering one. Many consider the brand to be overly-complicated and impossible to troubleshoot, and some refuse to work on these machines at all. But is this attitude really warranted?
All appliances everywhere work on the same principles, and Samsung is no exception. The idea that Korean appliances like Samsung and LG somehow work differently is pure mythology, and this short excerpt from o
Linear motors -- primarily in the form of linear compressors -- aren't new technology, but they've only been migrating into the appliance world over the past few years. These "new" compressors have their own unique failure modes and troubleshooting dos and don'ts. To really have a good idea of how to diagnose them, you need to understand how they work.
That's exactly what we show in this short excerpt from one of our longer technical training webinars. Give it a watch and learn something!
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,
Knowing how to properly use a schematic for your troubleshooting is key to saving money and time. In this short presentation, the Samurai shows performing circuit analysis to identify the most useful, but also the most convenient tests to quickly zero in on the problem. Topics covered include:
- reading schematic diagrams
- strategic selection of your reference voltage
- doing live testing (appliance plugged in and running) vs. Ohms testing
- using a loading meter to test AC line vol
Let's say you're on a call for a Whirlpool GI6FARXXY07 refrigerator. You notice that the evaporator fan isn't running, even when the unit isn't in defrost. "Simple enough," you think, and you disconnect the fan harness and check its resistance.
Wow -- 500 K-ohms! No way that's in spec. Gotta be a bad fan motor, right?
Before we get too hasty, let's step back for a moment and do what we should have done at the start -- look at the schematic. When we do that, we can pretty easily locate
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
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
Merry Christmas to all the Appliantology Brethren! Here's hoping that this holiday is capping off a great year for your business, and that an even better year is just around the corner.
In this video, we give a comprehensive answer to this question: "Why is it that high ambient temps cause high side and low side pressures to rise?"
This simple question about one specific sealed system problem scenario is a great opportunity to take a deeper dive into how sealed systems work, how they're affected by their environment, and how an issue in one area of a sealed system has ramifications for every other area.
Topics covered include:
The temperature/pressure relation
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
No matter what refrigerator problem you're called out for, no matter if it's for a warm freezer or a noisy fan or a leaking dispenser, there's one simple step that should you should always do before anything else -- before you or the customer even opens the doors of the machine:
Measure the compartment temperatures.
Simple, right? So why am I writing a blog post about it? Well, a lot of techs don't see why this is a step that you must always take when troubleshooting a refrigerator. Do
In the appliance repair world, we deal with two different kinds of thermistors: NTC (Negative Temperature Coefficient) and PTC (Positive Temperature Coefficient). Don't know what those terms mean? Don't worry, I'll break it down for you.
Despite both being thermistors, the only real similarity between NTCs and PTCs is that the resistance of both changes in response to temperature. Beyond that, they work quite differently and serve very different functions.
Here's what a typical NTC the
With the ongoing COVID-19 crisis, things are changing quickly. No matter how long or short the actual pandemic lasts, everything won't just go back to how it used to be, and if we appliance repair techs want to stay in business, we will have to adapt.
What exactly that adaptation looks like remains to be seen, but Team Samurai has been in the business long enough to have some solid ideas about it. Heavy sanitation precautions are something that is already happening and will continue to beco
We've got quite the library of awesomely informative webinar recordings here at Appliantology -- literally days worth of it! Don't believe me? Here's a little taste.
Push to start switches are extremely common technology in dryers, but do you actually know how they work? And do you know the fatal troubleshooting error that can lead you to misdiagnose them? Watch this short excerpt to find out.
If you want to watch the full recording and take your appliance repair skills to the next lev
Do you know the most efficient way to troubleshoot this washer motor, or would you go through unnecessary disassembly? Watch this webinar excerpt to find out.
This is just a short excerpt of a webinar that's packed with even more vital info on how to maximize your service call profitability through solid troubleshooting techniques. Click here to watch it now. This and 50+ hours more of awesome webinar recordings are available only to our premium members at Appliantology.
Sometimes, the schematics that manufacturers give us aren't as clear as we would like them to be. Take this refrigerator, for example:
There are a few confusing things going on with this schematic, but we'll start with the part I've circled. What is that rectangle? It's drawn with the same lines as all the wires, and we're seeing connections going directly to it. There's no label anywhere calling it out as a discreet component. Could it be that that rectangle really is a loop of wire
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