We covered not one, but two different workshop topics in our last webinar, and I now present to you the second one!
In this workshop about a dishwasher with a starting-and-stopping motor, we covered topics like:
How to nail this problem using a single test
Analyzing the wash motor circuit to understand how it works
Identifying how the board senses circuit current
...and more!
Click below to watch the full recording -- available only to premium tech member
How do you use a schematic to analyze a circuit, and how do you then apply that knowledge to a real-world troubleshoot?
That's the question we answer in this Schematic Workshop webinar! We start off by working through the most interesting parts of this dryer circuit, and then we move on to several more schematic exercises. You can watch an excerpt of the full webinar below:
Want to see the rest of the troubleshoot? Click below to watch the full recording and step up your trou
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
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
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,
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
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
Here's your problem statement: in this GE dryer, the timer doesn't advance in auto-dry. How do you approach this like a real tech, without making guesses and monkey-jabs?
In this excerpt from a longer webinar, the Samurai shows using the timer chart and the schematic in conjunction to form a foolproof troubleshooting plan. Give it a watch!
Want to watch the full recording? Click below -- viewable only by premium tech members.
Here's the problem scenario:
The customer's refrigerator has stopped running. You take a look at the start device, and it's completely burnt out -- enough so that you can see that the plastic housing has melted. You swap it out for a new start device and...
Still nothing. In fact, a quick voltage measurement shows that the control board isn't sending voltage to the compressor. Now the board needs to be replaced, too.
So what happened here? Did the start device just short out and t
A tech is troubleshooting the power supply for a Maytag dishwasher control board, and he finds some interesting readings. Using a LoZ meter, he reports finding 120 volts at the outlet and at the control board. But strangely, he also has 48 volts on neutral. What gives?
In our latest webinar, we unpacked all the electrical know-how and troubleshooting mojo that goes into properly diagnosing a problem like this. To figure out what went wrong in this troubleshoot, you have to answer the follow
Here's something for you sharp Appliantology techs to puzzle over: what in the world is the circled symbol on this schematic?
Is that a wiring harness? Maybe this diagram's strange way of showing a splice?
To figure out what it is, we've got to have a functional understanding of how Electrolux likes to design their water valve circuits. Let's look at a similar configuration that's drawn differently.
There we have it -- on this schematic, the engineers decided to throw
Happy Thanksgiving to all the Appliantology Brethrens!
I'm thankful to be part of a community of such sharp techs who are always willing to help each other out. Here's hoping you're popping open a cold one with the family and enjoying the things that matter most.
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
Here's the situation: the tech is working on a dryer that keeps blowing its thermal fuse. The tech has already replaced the fuse once, and it's now blown again. What could be causing this, and what's the best way to tell?
We'll start by looking at the heater circuit -- an essential step in any troubleshooting plan.
Pretty simple stuff. Just a cycling thermostat, a centrifugal switch, and a hi-limit thermostat. The thermal fuse that keeps blowing is the one in the motor circuit. I
As control boards, and especially multiple-board configurations, become more and more prevalent in appliances today, we need to keep our troubleshooting skills sharp and adapt. So what troubleshooting strategies should you apply when you're dealing with a computer board?
The good news is that you don't need to be a computer geek to work with boards. You just need a troubleshooting strategy for dealing with them, and you need to understand how they operate on a basic level. That's what the S
Bimetals show up all over the appliance world in all kinds of applications. Resistive Temperature Devices (RTDs) are widely used in ovens and ranges and are commonly called "oven temperature sensors." Both are devices that respond to temperature, but beyond that, they work completely differently and serve different purposes. Watch this short excerpt from one of our many technical education webinar recordings to learn all about these devices!
The full webinar covers all the common
Imagine you're out on a call, and you run into this:
As the picture says, the dryer runs like this. And even weirder, when you correct the wiring, it stops running.
Take a minute to think, then see if you can answer this pop quiz:
1. How does the dryer run in this configuration?
2. What's wrong about the wiring in this configuration?
3. Why does it stop working when you correct the wiring?
4. What one test could you do that would prove your hypothesis about th
Ever wondered what the inside of a gas dryer valve looks like? And what's the purpose of having two separate valves in one component? What about those mysterious "safety" and "booster" coils?
All of these questions are answered in this short excerpt from one of our many in-depth technical training webinar recordings. Give it a watch and, if you want to see more, click here to watch the full recording. This and dozens hours more of technical education are available only to our premium member
When you need to test a component, do you always need to just resign yourself to tearing apart the appliance until you reach it? Or is that a waste of time and energy (not to mention unnecessary liability), when you could be working smarter, not harder?
Let's say you're working on a Samsung dryer, and you want to measure the thermistor. You know the ohm spec (unfortunately they don't give you voltage drop), so all you need to do is get your meter probes on it so that you can compare. Is you
Brother Scott-afl ran into some unexpected trouble when trying to extend the defrost cycle on a Samsung RF28HFEDBSR/AA refrigerator. In his words:
Two puzzling things here:
First, why the difference in the error code reporting? It's a minor point, but that E/C difference seems odd.
Second, why is the procedure for extending the defrost not working, despite multiple attempts at following the instructions in the manual?
Both of these discrepancies boiled down to one thing: po
Our online appliance repair training site, MasterSamuraiTech.com, will have a few hours of downtime tonight (Monday, October 26, 2020) starting at 11pm eastern time as we install our brand spanking new website.
We will post any important updates right here at my blog.
If you are a current student, here's a quick overview of what you will experience once the new site is up and running.
UPDATE: The new site is up and running! Check it out for yourself.
In this excerpt from one of our many in-depth technical webinars, the Samurai breaks down in just a few minutes what causes ghost voltage. He'll show in simple terms what the term "capacitive coupling means, as well as how to do your voltage measurements correctly so that you'll never be fooled by an open neutral again.
Want to watch the full version of this webinar, along with 50+ additional hours of practical technical education? Click here to become a premium tech member today.
I've seen a few guys around the forums ask the same question: are surge protectors (also called surge suppressors) safe to use on refrigerators?
Best I can figure, this question comes from folks mixing up surge protectors with AFCIs and GFCIs (you can click here to read about how those devices work). But it speaks to a general ignorance of how surge protectors work. Well, why don't we fix that?
The reason surge protectors exist is to block voltage spikes -- those are large spikes in th
Picture it.
You're walking into the service call of a long day, but you're feeling good. You've got your tools in hand, you've done all the prediagnosis; you're gonna kill it. The customer lets you in, and while chatting affably he begins leading you to the appliance.
You can't place why, but a dark cloud of foreboding passes over you. You push it aside, but the feeling only grows. He's leading you downstairs now, into the basement. It's dingy down here -- clutter everywhere.
No,
Whether a control board in an appliance is simple or sophisticated, there's one trick it has to pull off: switching high AC voltage using low control voltage. They pull this off by using relays or triacs, devices that all of us are at least passingly familiar with.
But how do these very common control components work, exactly? And how is troubleshooting a relay different from troubleshooting a triac? That's what we'll look at today.
Relays: The older and simpler of these two devices, r
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