Here at Appliantology, our primary mission is to support appliance repair techs in performing prediagnosis: the method of performing as much troubleshooting as you possibly can before setting foot in the customer’s home. Prediagnosis is the biggest factor in increasing FCC (First Call Complete) rates, and the higher the FCC rate, the higher your company's profitability.
So how exactly does one prediagnose, and how does Appliantology help with that? Well, let's walk through the journey of an
A tech here in the Appliantology forums ran into a surprising customer complaint about a microwave: it's doing its job too well! They say that it's cooking food way faster and way hotter than it used to.
(The above picture is a slight dramatization.)
So, our tech took a reasonable step and measured the amps going to the microwave. After all, if the magnetron is producing more watts than expected, it will have to be drawing more amps.
Measuring Power Consumption
His meas
You open up the terminal block on a Bosch range, and you see this. What's wrong with this picture? (Hint: those of you who have watched this webinar recording should know what's up).
A few questions for you sharp Appliantology techs:
Will the machine run in this configuration?
Why is it not okay to leave the machine in this configuration?
Does this machine have a 3 or 4 wire power cord?
How would you correct this situation?
Let me know your answers
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
Are the dispenser heater and fill tube heater in series or parallel? Or perhaps they're neither?
BONUS QUESTION: If both heaters have 6.3 kohms of resistance, roughly what resistance would you expect to read from pin 1 to pin 2 of the connector?
Sound off in the comments!
Both of the big Korean manufacturers -- LG and Samsung -- have a little trick that they like to use in their schematics. While I think they do it to keep the lines from becoming too much of a tangled mess, it can sometimes be a bit unclear for the uninitiated. Here's an example of an LG refrigerator schematic:
The whole picture is a bit much, but notice all those bubbles popping up around the schematic? Let's pick one of those and focus in on it. Here's one coming off the sub PCB:
Anytime you work on a refrigerator with a control board, you've got multiple NTC thermistors in play. With how ubiquitous these devices are, it's important to know them inside and out -- especially how to test them. That's why we've made a webinar all about NTC thermistor technology for your viewing pleasure!
In this short excerpt from one of our many technical training webinars, we cover topics like:
What is an NTC thermistor used for and where will you find them?
What does
How are we as techs supposed to understand the specifications we see on a split-phase motor's label? What's the difference between a motor's output power and its input power, and which of those specs is given on the label? What do acronyms like FLA and LRA mean? All that and more covered in this short video on motor specifications.
This is just a short excerpt from the great technical discussions we have every other Saturday during our Live Dojo Workshops. If you're not joining us for these
I want you to take a look at the door switch I've circled below. Think about it for a minute, then answer one question: what single test could you do to prove beyond a doubt whether or not that door switch is operating within spec?
There's no trickery going on here -- it's just a simple switch. But many techs will test it using a flawed, limited test that has a big chance of leading them to the wrong conclusion. And they'll do a bunch of unnecessary disassembly. Post your answer in th
More and more folks are doing online training webinars these days -- so many, in fact, that it can be impossible to keep up with them all. Recently, Samsung and MSA both put out training webinars on Samsung dishwasher technology and troubleshooting, and I figured I would share the love with the Appliantology Brethren.
In the links below, you'll find my notes and screenshots from both webinars. Topics include:
Troubleshooting the OC/OE error
Identifying common sources of leaks
This microwave will run with the door open -- lucky for the customer, it also doesn't heat. But why is the turntable able to run with the door open? What do you do when a circuit doesn't work at all the way it's supposed to?
That's exactly what we discussed in our latest Live Dojo workshop.
Topics covered include:
Microwave door interlock switches
Turntable motor circuit analysis
Control board algorithms and relays
Theorizing a reasonable failure scenario
Let's take a look at the interlock switches in a Kitchenaid microwave-oven combo unit with a simple question to answer: which of the microwave interlock switches should be closed when the door is closed, and which should be open?
Here's the schematic for this model with the switches in question circled:
Should be simple enough to find the answer to our question. In fact, most schematics worth their salt tell you the state the unit is in as shown. Ours has just such a note:
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.
One of the many fine techs here at Appliantology posted his story with a Maytag washer that wouldn't spin in the Appliantology forums.
The initial situation in his words:
On top of this, there was one more strange symptom:
Given this strange behavior, he was understandably thrown on how to proceed.
After changing all those parts, no resolution! But finally, he found the issue:
Lesson learned indeed! And thank you for sharing your hard earned lesson with us. Now we a
It's always the old-skool style circuits that have the most interesting electrical issues, isn't it?
In this workshop, we took a look at just one such machine. A missing neutral in the power supply doesn't have the effect that you would necessarily expect. For example, in this dryer, the timer motor runs on 240 VAC, but the drive motor runs on 120 VAC power. With a missing Neutral, the drive motor won't run, but the timer motor will. We go all into that, as well as the kind of troubleshooti
An interesting topic came up here in the Appliantology forums a little while back:
The tech was working on an electric dryer that was DOA -- no lights, no response to button presses. He put his multimeter to the LoZ setting (as you should always do when making AC voltage measurements!), and he started checking for the power supply to the appliance at the terminal block. Here's what he got:
L1 to N: 0 VAC
L2 to N: 120 VAC
L1 to L2: 20 VAC -- and while the meter leads are held
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
An Appliantologist in the forums ran into a bE error on an LG dishwasher, which perplexed him. In his words:
A bubble error would seem to indicate oversudsing, but our tech said that wasn't the case.
Fortunately, Brother Slav had the answer for us:
Turns out, this so-called "bubble error" can mean all kinds of problems that have nothing to do with suds, such as a leveling issue:
Or a problem with the pump:
You can check out the full list of bE error code
If a dryer's motor isn't running, and you hear a strange humming noise coming from the start switch, what does that mean for the switch? And if you want to test that switch, what's the best way to do that?
These are questions that we answer right here in this short excerpt from one of our many in-depth technical training webinar recordings. Give it a watch and learn the answers for yourself...
Want to watch the full webinar recording? Click below -- viewable only by premium m
We had an interesting discussion at our most recent Live Dojo workshop! This dryer only runs when the push-to-start button is held down -- a relatively simple problem, but troubleshooting it requires us to understand the entire motor circuit and how it works on startup.
We began by using Ten-Step Tango to orient our troubleshooting, identifying our Load of Interest and analyzing its circuit.
This led us to examining how the start switch works, which includes some interesting components
In this interactive webinar workshop, we explored an LG gas dryer issue that had stumped an Appliantology tech. We performed a forensic analysis on the troubleshoot to figure out how it could have been improved, and then we moved on to thoroughly examine the circuits and understand how they work.
This and our dozens of other technical training webinar recordings are only viewable by premium tech members at Appliantology.
Topics covered include...
DC and AC loads
Compute
This past Sunday, we gave a webinar covering everything you need to know about thermal controls in dryers and the underlying technologies behind them. The full recording dives into all the details of identifying, understanding, and troubleshooting these ubiquitous devices.
In this short clip, we'll introduce you to the three technologies and show how different manufacturers give them various (and sometimes confusing) names.
Want to watch the full webinar recording? Click belo
In our latest troubleshooting workshop, we start with a seemingly simple problem -- overly long dry times -- and walk through all the surprising pitfalls that you could be ensnared by. Topics include:
Correctly measuring dryer vent airflow
Differentiating between real diagnostic tests and fluffy sales features
Identifying dummy troubleshooting directions and errors in manuals
Learning why you should always use amps rather than ohms for troubleshooting AC loads
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.
Wan
See if you can identify two things on this Samsung dishwasher schematic:
1. Where does the control board receive line and neutral?
2. Where do the sub-control boards get their DC power supply?
The answer to the first question can be found easily enough, if you have a little schematic reading experience. But it's a bit trickier for those who don't have as much practice.
For one thing, line and neutral aren't explicitly labeled. Just wire colors are given, but fortunately
