Posted on March 10, 2015 by Scott Brown - Presentations, Tech Talk
A Master Samurai Tech Presentation:
Troubleshooting Appliance Electronic Control Boards
Learn from the Samurai and become a troubleshooting master!
Using a Whirlpool dishwasher as a case study, the Samurai explains each step in the process of troubleshooting electronic control boards in appliances, revealing the schematic mysteries to all who want to learn.
In this 38-minute video, you will learn:
- Basic troubleshooting techniques with broad applications to all appliances
- How to use tech sheets properly
- How to get those control boards to talk to you
- How to identify suspected problems using the schematic diagram
- How to formulate a troubleshooting strategy based on schematic analysis
- How to identify where to make electrical measurements
- About triac-gated neutrals in AC loads with standing voltage
- The difference between loading and non-loading voltage meters and when and why to use each
...and much more!
You will have LIFETIME ACCESS to this video!
Here are a few tantalizing screenshots of the presentation...
One small price of admission gains you lifetime access to this valuable training video as well as the ability to ask follow-up questions in the comments section. Watch it as many times as you like as part of your journey to become a Master Samurai Tech!
Note: if you are enrolled in Advanced Schematic Analysis and Troubleshooting, then you have access to this presentation in your course materials.
Click here to begin your journey of Total Appliance Enlightenment!
Posted on March 1, 2015 by Scott Brown - Academy Talk, Tech Talk
Here at the Samurai Tech Academy, we're always thinking about our students! (That's not quite as creepy as it sounds.)
In yet another example of the STA's devotion to the needs of our students, we have added new Module Exams to most of the modules in the technical courses. Many of you were asking for more challenges along the way to make sure you're really getting the material. Module Exams are a great way to revisit the info from all of the units you've studied and make sure you've nailed it before moving on to a new module.
IMPORTANT: if you are currently working through Fundamentals or Refrigerators, you will have to go back and take any exams for modules you've already completed before you can move forward. I hope you will see this as an opportunity to review and practice the material from those modules, and know that it will help you when you get to the Final Exam!
If you have already completed either course, you can still go back and take the exams for funsies!
But wait! There's more!
Another change we made was a three-attempt limit on the quizzes that come after each unit (lesson). We did this because if a student needs to re-do a quiz more than three times, there's something wrong either with the student's attention to the material presented in the unit or with the way the material is presented. Either way, we need to troubleshoot that!
So here's the drill: if a student requires more than three attempts to pass a quiz (and all unit quizzes require a score of 100% to pass and move on to the next unit) then the software sends me an email and the student's progress is temporarily stopped until we can talk either by phone, email, or the Student Forums.
After I've administered the appropriate gray matter massage, the student is re-enabled to re-take the quiz and continue on their merry way. Ultimately, the goal is to encourage more student-Samurai interaction as needed to help the student master the material.
Let’s face it: appliance repairs are expensive due to the real costs of running a full-time, professional appliance repair business. That's why so many folks are trying to save time and money by learning how to fix their own appliances. And how 'bout the supreme satisfaction that comes from kicking major appliance boot-ay? BOOYAH!
Appliantology.org is a powerful repair resource for DIYers. You've got professional appliance techs giving you personal help. But all too often, that help comes to a screeching halt when you gotta have basic electrical troubleshooting skills to finish the job, such as reading schematic diagrams and understanding the technology that you’re working on.
DIYers are a diverse group but, in my decades working with them online, I see that most DIYers share two characteristics: they have above average to great mechanical skills, but are weak on electrical skills.
With today’s increasingly computerized appliances, unless you have a minimum baseline of electrical troubleshooting skills, you’re just going to be flailing about blindly in a sea of technical symbols and words for all but the simplest repairs. Any electrical explanations or instructions offered to you will just sound like Chinese. You can see the problem here.
What’s a bruthah from anothah muthah to do?
Samurai to the rescue! The electrical and troubleshooting skills you need are very learnable and affordable at the Samurai Tech Academy.
The Fundamentals of Appliance Repair course would be an awesome boost to your ability to repair all kinds of things around the house. Basic electricity, electronics, gas, electric motor systems, and troubleshooting with schematics are all timeless skills with broad application that will give you valuable insight into the inner workings of numerous electro-mechanical systems in your home.
You can acquire these skills inexpensively and conveniently in our up-to-date, comprehensive, online Fundamentals of Appliance Repair training course. The course tuition will pay for itself after just one or two DIY repairs!
It's an investment in the most valuable asset you have: YOU!
Other methods of technical training available today are DVD packages, in-person training, and correspondence courses. See how online learning compares with these other training methods.
Dance with me now:
- Modern appliances are complicated electro-mechanical machines that are increasingly using single-board computers to control them.
- Tech help at Appliantology.org can only take you so far if you don’t understand the underlying technology you’re dealing with and you can't use schematics to troubleshoot and make basic electrical measurements.
- The Fundamentals of Appliance Repair course teaches you all of the basics you need to ascend to a higher level of DIY ability.
- The skills you learn in the course are timeless and have broad application.
- You could even earn extra beer money on the side while you keep your regular job.
- Better yet, do appliance repair full-time and earn up to $120K/year as a skilled appliance tech!
- Complete the Free Sample Course to get a foretaste of the empowering wisdom that awaits you along with a discount coupon!
Posted on January 10, 2015 by Scott Brown - Tech Talk
Dryer Schematic Quiz 2 - Click for Larger View (opens in a new window)
1. To calculate the current flow in this simple series circuit, you first need to calculate the total circuit resistance.
The heater resistance is given as a range so, for simplicity, let's assume something in the middle, say 8 ohms.
The resistor ohms are also given as a range so let's again use something in the middle, say 4500 ohms.
Similarly, a mid-range resistance on the timer motor would be 2200 ohms.
Adding these up, the total circuit resistance is about 6708 ohms. Now we can calculate total circuit current using Ohm's Law:
I = E ÷ R = (total power supply voltage) ÷ (total circuit resistance) = 240 vac ÷ 6708 ohms = 0.036 amps.
2. The timer motor is a 120 vac synchro motor but the circuit is supplied with 240 vac. The purpose of the resistor is to drop some voltage so that the voltage across the timer motor is something less than 120 vac. How much less? You can calculate the voltage drop across the resistor because we know the circuit current, 0.036 amps. In a series circuit, current is the same at all points and through every load. Therefore, the voltage drop across the resistor is
E = I x R = (0.036 amps) x (4500 ohms) = 162 vac.
The remaining voltage is dropped across the heater and timer motor according to their resistances.
3. Ohm's Law again:
P = I2 x R = (circuit current)2 x (heater resistance)
= (0.036)2 x (8 ohms) = 0.01 watts
Still confused? I explain and demystify circuits, reading schematics, troubleshooting with schematics, motors, and all the other basic skills that every appliance tech should have in our Fundamentals of Appliance Repair training course.
Posted on January 8, 2015 by Scott Brown - Tech Talk
Dryer Schematic Quiz - Click for Larger View (opens in a new window)
1. Which timer cycle is the schematic showing?
Looking at the timing chart, we see that the cycles on this dryer fall into two main groups: auto and timed. The big distinction between the two is timer contacts TM-OR (timed dry cycles) and TM-WB (auto dry cycles). Since the schematic shows that the TM-OR contacts are made, then we know we're in a timed dry cycle. Checking the state of the other contacts listed in the timing, we see that the schematic shows them all as open. Therefore, we know that this dryer schematic is showing the dryer at the End-of-Cycle. Which also helps answer the next question...
2. Is the motor shown running or not?
We know from the forgoing analysis that the dryer is shown at end-of-cycle, so the motor is not running. But you can also tell by looking at the centrifugal switch contacts on the motor. They are shown in the retracted state meaning the motor is stopped.
3. Why won't the timer advance in Auto Dry cycle when the operating thermostat is closed?
In Auto Dry, the timer chart shows timer contacts TM-WB are made. With this in mind, trace L1 to the timer motor. L1 comes through timer contacts BK-BU to one side of the timer. L1 also comes through timer contacts BK-R, through the thermal cutoff, operating thermostat, and high limit to one side of the heater. But it also branches off through the resistor and timer contacts TM-WB to the other side of the timer. Since both sides of the timer have L1, the voltage difference across the timer is zero and the timer motor does not run.
Still confused? I explain and demystify circuits, reading schematics, troubleshooting with schematics, motors, and all the other basic skills that every appliance tech should have in our Fundamentals of Appliance Repair training course. Complete our free Sample course and get a discount off your tuition.