Susan Brown

[Susan Brown]

Hi Ronald,

The two answers that are not invasive and do not involve disassembly are:
Temperature
Amps

Measuring pressure is invasive and looking at the frost pattern requires disassembly.

Let me know if you have any other questions.

[Susan Brown]

Hi Dale –
I assume you are talking about the “Kleinert” book that we have some assignments from. See the Orientation module, unit 1, Preflight Checklist item 4.

Also see this topic here in the Forums:
https://my.mastersamuraitech.com/appliance-repair-course-support/student-forums/topic/link-for-the-pdf-textbook/

[Susan Brown]

Basically:
While the fridge is running, you would use the schematic to find the pin locations for the sensor so you could measure the voltage across it (DC voltage). You would need to know the specifications (from the service manual/tech sheet) so you would know how to interpret the number you get. Not all manufacturers give voltage drop specs.

[Susan Brown]

Hi Zachary,

When looking at schematics, it can sometimes be hard to see if a load is in series with other loads or in parallel. Some people are good at tracing the voltage lines out by just looking at them, but for some it’s helpful to think of it the way we describe – imagining that we are the load, and reaching out with each hand to touch Line and Neutral at the power supply (or L1 and L2 if it’s a 240v circuit). We will take the easiest route – if there is a shunt (often a closed switch), we will take that to avoid going through another load. It’s just a little visual trick to help us out.

As you get more into the Troubleshooting material, you’ll learn more about why it’s important to be able to see how a load is laid out in a circuit, relative to other loads in the appliance.

Does that help?

[Susan Brown]

The switches determine which route L1 takes.

[Susan Brown]

First, I always like to make sure we are looking at the correct light on the schematic, since there are several.

Any load that is supplied with L1 and L2 will run on 240v. L1 and N is 120v.

There are two ways that L1 can get to the light – that is what we are asking for in Question 2.
One of them is Through the light’s bimetal switch, as you say. The other has to do with that jumper wire (BK-J).

Did you see the explanation that showed up on the results of the quiz for this question?

When the surface element is first switched on, the light gets L1 through the L1 to H1 contacts of the infinite switch and the black jumper wire. This can be easy to miss because the two ends of the black jumper aren’t explicitly shown as being connected.

During the element’s operation, once it gets hot enough, the light’s bimetal switch closes, providing another path for L1. This means that even after the infinite switch is opened, turning the element off, the light stays lit until the element cools off enough for the light’s bimetal to open again.

[Susan Brown]

Check out this topic – does it help you see the answer?

https://my.mastersamuraitech.com/appliance-repair-course-support/student-forums/topic/mod-6-unit-7-quiz/

[Susan Brown]

I assume you are talking about the closed detector switch having an impact on the circuits.

I think the easiest question to answer first is the voltage drop across the Safety.

If you do the “Zen Trick” (see the first video in Unit 5), is the Safety in parallel or in series with the other loads? Does that lead you to know what the voltage drop would be across it?

[Susan Brown]

Hi John,

All 120v circuits will have N at one end of their schematic, and “Line” on the other end – often shown as L1.

Line voltage is 120v with respect to Neutral.

When you see L1 and L2 on either end of the diagram, this indicates a 240v circuit, because both sides of the circuit are providing 120v which combine to form 240v.

We’ll describe this in more detail in Units 6 and 9, so hopefully it will all become clear then!

[Susan Brown]

Hi David,

These are the two parts of the schematic I look at to answer the questions you missed. For example, question 8. You need to know where the bake and broil ignitors are, so you can see which test points correspond to which one. And since they are designated with letters, you need the key to figure out which is which.

Do you see what the test points are for the
1. Bake ignitor
2. Broil ignitor

You would want to look for L1 and N.

[Susan Brown]

Hi Nathan – see the email I just sent you

[Susan Brown]

If an appliance is plugged into (or in the circuit with) a GFCI outlet, and the outlet trips for some reason, that will cut off power to the appliance. Resetting the outlet should restore power.

Non-GFCI outlets don’t have that feature – if they are not providing power it is because the circuit breaker tripped or a wiring issue with the outlet/circuit.

[Susan Brown]

Hi Douglas,

From the unit: “Depending on the model, you can either have a single spark module that sends sparks to all the burners (called multi-point ignition) or you can have a separate spark module for each burner (called single-point ignition).”

I know it seems counterintuitive at first, but if each burner has its own spark module, then it only ignites at that one point. If there is only one spark module for the whole cooktop, that one module needs to ignite at multiple points.

Does that make sense?

[Susan Brown]

Hi Andrea,

The key here is the weird 78v reading. This is the kind of thing you get with “ghost voltage” which is often related to an open neutral.

So the two answers we are looking for are:
That you are probably seeing ghost voltage and should have set your meter on LoZ or used a loading meter to make this measurement
That you are probably dealing with an open Neutral situation

[Susan Brown]

Hi Raja,

#9: we are using “switch” as a verb there. In other words, what does the PCB control: line or neutral?

For #10, see this section of the schematic:

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