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
The general rule for dryer vent airflow is that, if the airflow feels like a breath (even a strong one), then you have a problem. This rule of thumb will serve you well a lot of the time, but sometimes a "calibrated palm" just isn't enough. Sometimes, you need to get an actual measurement of the airflow so that you can compare it to the specifications.
What you really want to know is the volumetric flow rate of the dryer exhaust. That is, how much air it's pushing out over a particular peri
We've all been there: you're looking up the part that you need for the job, and the price tag about knocks you out of your chair. No way that heating element costs that much to produce! Maybe your concern isn't just for yourself -- you're interested in saving the customer some money.
Despite the sometimes exorbitant prices, there are many good reasons to go with the OEM part over a generic one.
OEM parts are generally better quality and make for a more reliable repair. You're going
Ghost voltage is a term that you'll hear used in tech circles, and often incorrectly. Ghost voltage is the name of a very specific phenomenon, but I've seen it used variously to refer to failing under load, high resistance connections, and even simple open circuits. What does it really mean?
What we call ghost voltage is transient, seemingly sourceless voltage. It does, of course, have a source. You know how when current flows through a conductor, it produces a magnetic field? Well that mag
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.
What do you do when an appliance, despite all appearances of normality, simply refuses to do its job? The Samurai and I were forced to answer this very question today.
The culprit: A KitchenAid KGRS505XWH05 double oven all gas range.
The complaint: The customer told us that neither the top nor the bottom ovens would ignite, but the cooktop worked fine.
The customer's description turned out to be about right (for once). The upper oven broil and lower oven bake ignitors would glow f
What we call Parts-Changing Monkeys (PCMs) around here at Appliantology are techs who rely on pattern recognition, tech myths, and blind luck to make their repairs. Case in point with this example of a GE ZGU385 gas cooktop, where said PCM figured he would get lucky by replacing a couple of components that seemed related to the problem, apparently without any troubleshooting beforehand.
Spoiler: he didn't get lucky.
Real technicians don't rely on luck to get things fixed. We rely on kn
Put simply, diodes are devices that only allow current to flow in one direction. In DC circuits, this means that a diode can either act as a conductor, just as a stretch of wire would, or as an open in the circuit, depending on the configuration. See the examples of DC circuits with diodes below:
That arrowhead-like symbol is the diode. The fat end of the arrow is the positively charged anode, while the narrow end that meets the straight line is the negatively charged cathode.
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
Self-clean sounds like a great idea, right? Just push a button and watch your oven burn away all that caked-on grease and charred food.It certainly makes for a good selling point. But is this no-hassle cleaning feature really all it's cracked up to be? And what is the best way for the customer to use it (if at all)?
First off: does it actually work? Can the oven clean itself just by getting really hot? Yes, definitely. Self-cleaning isn't just a gimmick, and when used properly, it does actu
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
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
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
Sometimes, the hardest part of being a tech is dealing with the customer. Customers always have expectations, some reasonable and some not, and we have to manage these on top of performing our diagnostics and repairs.
A large part of being a real technician is knowing when to trust your own expertise over customer demands. This struggle generally manifests in two ways:
1. The customer has their own diagnosis that they're sure is correct. We've all encountered this before. Something alo
Here's your scenario: you're working on a Whirlpool CAM2742TQ2 Washer, and you've determined that the auto temp control (ATC) has failed such that it won't energize the water valves and allow the machine to fill. You intend to replace the ATC, but it's on backorder. Is there any clever trick you can think of that will at least get the customer going temporarily while they wait?
Time to crack out the schematic.
It looks like there's a lot going on here, what with all those alphabe
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
Whether you were aware of them or not, Hall effect sensors are everywhere. Any time you see a motor on an appliance with any kind of RPM feedback or speed signal, there's a Hall sensor on that motor. As with any ubiquitous appliance technology, it's important for us techs to know how they work. A deeper understanding of the technology means a deeper understanding of how to troubleshoot it.
So: what is a Hall sensor, and how does it work? These are semiconductor devices, so as with most elec
Why is it that manufacturers (such as GE, Electrolux, and others) always recommend that you seal any splices you make in their refrigeration units with silicone grease? The simple answer is that it keeps out water. This is obviously desirable because water can both corrode and short out electrical connections. A splice is already a weak point in a circuit, so especially in wet environments, you want to give them as much lasting power as possible.
And it gets even more interesting when you'r
Information has always been the name of the game for appliance repair techs. Our jobs are all about locating and making extrapolations upon information such as specifications and measurements. If we can't access at least a baseline level of information for a particular job (at the very least the schematic), then it's almost impossible for us to do our job.
The meteoric rise of mobile technology and the Internet over the past few decades has hugely expanded how much information we can access
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
Tell me what's wrong with this picture:
No, your eyes are not playing tricks on you -- that schematic really is showing a split-phase compressor being run by an inverter board.
If you're sitting there sputtering and foaming at the mouth in disbelief, thinking, "That can't possibly be correct," then congrats! You had the correct reaction. What this diagram is showing simply can't line up with reality. Split-phase motors are never run using inverter boards -- the very idea is nonse
There's a goal that any tech worth his salt should have when he heads into a service call: troubleshoot the machine until he has logically and definitively located the problem.
Most of the time this goal is achievable, as long as you have the documentation for the appliance you're working on. You can take measurements and compare them with the specifications from the manufacturer until you find what's not within specifications. This is called analytical troubleshooting and is, in fact, the
You're fighting a constant battle in the appliance repair trade to get the most money out of the time you spend. One of the biggest problems you face is unprofitable service calls. Most often these crop up as repairs that are close to the replacement cost. What customer is going to opt for a $300 repair when they can buy a new dryer for $400?
Fortunately, there are 2 simple steps you can take to weed out 95% of these kinds of calls. These steps are prediagnosis and flat-rate pricing.
There are some electrical terms that are often used in vague and incorrect ways by the general public. This can make things confusing for us techs, especially those new to the craft, because these terms have precise meanings when used by those in the trade. A couple of these words are short and ground.
Short is often used by the non-technical to refer to any "bad" circuit. The term "short circuit" is a popular one to throw around in this sense. In reality, a short is just one of multiple di
New technologies are never invented specifically for household appliances. We always get hand-me-downs. But just because a technology was used first in a different field doesn't mean that we're familiar with it already when it reaches appliances.
TMR (tunnel magentoresistance) sensors are one such example. Coming to us from the world of computer electronics, they serve the same purpose as Hall Effect sensors but work completely differently.
A TMR sensor consists of two ferromagnets sep