Samurai Appliance Repair Man's Blog

... and may God have mercy on your soul.

If you're troubleshooting a defrosting problem with your Samsung refrigerator, one of the first things you'll want to do is manually put it into defrost mode so you can use your meter and see if the control board is sending 120vac to the defrost heater.  Here's the procedure that'll work for most current Samsung refrigerator models:


(click for larger view)

When troubleshooting electrical problems with appliance, like no-heat complaints in dryers, you absotootly gotta have the wiring diagram / tech sheet that comes packaged with the appliance.  The manufacturers cleverly hide these inside the appliance to keep owners from finding them and losing them.  I love when I go out on a job and need the tech sheet but it's been removed from the appliance.  The customer then informs that they took it and filed it so it wouldn't "get lost" but they can't find it.  Folks, that's a show-stopper.  You cannot troubleshoot electrical problems, except for the most simple and obvious ones, without the tech sheet.  Just ain't gonna happen.  

Strip charts are nice because they focus only on the circuit and components involved with the specific complaint; in this case, no heat.   Let's take a look at the heater strip chart on this beast:



I've highlighted the key components in the hearing circuit that should be checked.  You can start with resistance checks if you like.  Note the thermistor resistances are given.  

But being as how I am an experienced appliance warrior, I like to do live tests with the voltage on the circuit.  

This is especially easy in this case.  Just disconnect the two common wires from both heater relays (violet and red wires), secure the wires so they don't touch anything and then run the dryer on a heat cycle.  In a properly functioning hearing circuit, you'll have 120vas at both the NO (black) and the violet and red wires that were disconnected from the heater relay.  Whichever side is missing the 120vac is the problem side.  

Can also disconnect the common wire from the heating element, secure it, and run the dryer.  See with side of the heating element circuit isn't giving you 120vac: either the control side or the motor side.  Whichever is missing the 120vac is the side with the problem.

Source: Maytag Bravo MED6400TB0 electric dryer no heating

from the Bosch Service Manual:
DISHWASHER TEST PROGRAM ERROR CODES (on 2-digit digital displays):
0 – No faults
1 – Aqua Sensor (Sensotronic) fault
2 – Heating system fault (heater, Hi-Limit, flow switch, NTC, control module heater relay)
4 – Water filling fault
8 – NTC (temperature sensor) fault
16 – Water switch fault

Fault codes add up for multiple faults
(e.g. heating + water filling fault = 2 + 4 = 6)

I'm not a Bosch master, but it looks like 21 would be 16+4+1
Is there enough water in the Dishwasher ?

Source: Bosch SHX56B02UC Dishwasher

Replacing and re-programming the control in these Bosch dishwasher is a pretty  straightforward job.  But the instructions for the reprogramming are a little different from what you might actually see.  

Here's a video showing how to replace the control.  

And here are the written instructions from Bosch (click to enlarge):



In the video, the re-programming portion is the last 30 seconds or so of the video.  Notice that what they show in the video doesn't quite match up with what's shown in the video, in particular, the programming code shown in the display.  In the video, you see him cycle through a series of programming codes from 20 through 29 (this is how you'll usually see it in the field for models with the LED display) until he gets the code he wants, in his case, "21."  

In the written instructions, OTOH, they talk about programming codes of C0 through C4.  The discrepancy is that in the written instructions, they're using "C" to mean "code."  On the display, just ignore the first number ("2") and go by the the second number that changes as you cycle through it.  

So, for example, if your model number is SHU43C06UC, the target code is "1" and you cycle through until you see "21" in the display.

Use your model number to look up and buy the replacement control board here.  Comes with a full one-year, no-hassle warranty, even after it's already been installed!

Source: Bosch  D/W Model# shu43c06uc/17