We run into water inlet solenoid valves in many different situations -- washers, dishwashers, refrigerators -- so it's important to have a firm grasp on exactly how they work. For example, I just talked with a tech recently who was wondering why low water pressure can cause inlet valves to leak.
It seemed counter-intuitive to him, and he's not wrong. Wouldn't it make more sense for high water pressure to cause leaking? But once you learn exactly how these valves work, it will all make sense
Many techs are intimidated when it comes to troubleshooting control boards. After all, we're talking about computers here -- computers that just so happen to run appliances. But as complicated as that may sound, control board troubleshooting really boils down to just three things: measuring your inputs, measuring your outputs, and understanding the board's algorithm.
Let's start with inputs. Input just means anything, be it a power supply or some information, that the board receives f
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
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
Join me on another short troubleshooting journey -- this one taken from a real tech's experience that he posted on Appliantology.
You're troubleshooting a Samsung dryer that won't start-- the control panel will let you select a cycle, but it won't actually run if you press the start button. But the real head-scratcher is that, despite not being able to start a cycle, the machine always runs when the door is closed.
Sounds tricky, but as you'll see, the troubleshoot is pretty simple if
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.
All
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
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
Vent hoods are pretty simple appliances -- something you've probably surmised if you've ever looked at the schematic for one. Usually, all they have going on is a blower motor and a couple of lights. When it comes to troubleshooting a hood, there are just two technology-related concepts you need to be familiar with: venting specifications and how multi-speed motors work.
First, venting specs. As with any machine that produces exhaust as part of its operation, vent hoods have certain require
VFD (Variable Frequency Drive) systems have been around long enough now that most of us know the procedure for troubleshooting them. You have three main tests that you perform:
1. Check for the PWM (Pulse Width Modulated) signal from the main control to the inverter. This is a DC square wave data signal that alternates between 0-5 VDC. The inverter has to receive this signal from the main board in order for it to run the motor.
2. Check the 120 VAC input to the inverter board. This has
PSC (Permanent Split Capacitor) motors are nifty pieces of technology that you'll most often encounter in Whirlpool's VWM washers. They operate a bit differently from your typical split-phase motors. Rather than having a dedicated start winding and run winding, with each winding having different specifications, PSC motors have two windings that are physically identical. The only difference between them is in what direction the windings are wound.
Another big difference between PSC motors an
Let's take a look at the sine wave you would see if you hooked up an oscilloscope to a typical household power supply. This is showing reading line with respect to neutral.
Hopefully you're already familiar with using a sine wave to represent AC voltage like this. To define a little terminology: the peak voltage (shown in green) is the voltage difference between the middle line (0 VAC) and the highest point of each peak. This diagram shows 170 VAC peak. Peak to peak voltage, on the ot
Think you know your circuits? How about we put that to the test!
In this excerpt from one of our many illuminating webinar recordings, the Samurai traces out the circuit for a refrigerator evaporator fan. Interestingly, the neutral side of the fan's power supply goes through both the defrost terminator and the defrost heater. How can this be?
Watch this excerpt and ponder the mystery for yourself. When you think you have the answer, click here to view the full webinar and see if you go
Ever seen a capacitor somewhere in a split-phase motor's circuit and wondered what exactly the point of that thing is? That's what we'll talk about in this blog post.
There are two different types of capacitors in split-phase motor circuits: start capacitors and run capacitors. Each type has a different set of parameters and serves a different purpose. But before we get into these specific types of capacitors, let's take a quick review on capacitors in general.
Capacitors aren't compli
One of the Appliantology Brethrens presented a small head-scratcher for us the other day about a GE GTWN4250D1WS top-load washer:
Sounds like a real problem, doesn't it? Back in the good ol' days, when you set a top-loader on maximum fill, it would fill that sucker all the way up. But wait -- before you start tearing things apart to take a look at the pressure sensor, let's listen to some words of wisdom from Brother @sh2sh2:
Ahh, well now, looks like we were about to get tricked!
Take a look at the circuit for this electric cooktop element. Notice anything odd about it?
Looks pretty straightforward, right? Well, it certainly is straightforward when the simmer switch isn't closed. Here's what the circuit looks like when it's not running on simmer.
L1 goes through the simmer select board and a temperature-controlled switch, and L2 goes through the relay board and a couple other switches. Standard stuff for one of these elements.
But what's going
Here's our scenario: you're working on a Samsung WA50K8600AW washer that won't advance in the cycle. Error codes and test modes aren't telling you anything useful, and the control doesn't even seem to be trying to advance the cycle. You've checked the air tube connected to the pressure sensor, too, and everything is clear there.
What can you do here? Do you just call it a bad board and move on?
Let's see if there's a smarter test we can do on this one. What if we could test the signal
Take a look at this LG gas dryer schematic, paying special attention to the circuit with the flame detector.
If you trace it out, it becomes a bit puzzling what that circuit is actually doing. The hi-limit thermostat, the safety thermostat, and the flame detector don’t appear to have any direct effect on the gas valve coils as you would find in other dryers. So what purpose do they serve?
This markup makes it all clear.
Unlike many circuits that use controls li
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
Unlike when we first started Appliantology, the Internet is now full of appliance repair support resources. From Facebook groups to subreddits to Voxer and Telegram groups, you've got your pick of the litter when it comes to what flavor you'd like.
Are there advantages to using a private forum-based site like Appliantology over the social media plantations? You betcha: Privacy and Functionality
Feeding Big Brother
All the Big Tech social media sites have one thing in common: they
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
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
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