Problem statements and Load of Interest (LOI) power supply circuits

Every other week, Master Samurai Tech/Appliantology.org holds a Live Dojo workshop where techs gather to workshop various technical and business problems. These workshops are help online via Zoom at 10 AM ET and last for about an hour, sometimes a little more. This post is a recap of the Live Dojo we had on Saturday, January 6.

In this workshop, the team discussed technical issues related to a malfunctioning gas range, tracing the power supply circuit for the Load of Interest (LOI) and the importance of clear and concise problem statements in troubleshooting. The team then shifted their focus to issues with a washing machine’s motor and drum, troubleshooting steps for a malfunctioning motor, and issues with a meter’s flakiness.

We began by tracing the power supply circuit for a bake ignitor in a GE gas range. The situation is this: You’re on a service call and you’re troubleshooting a problem using our world-famous Ten Step Tango troubleshooting procedure. You’ve made a solid Problem Statement (Step 1 of the Tango), you’ve done a schematic overview (Step 2), and you’ve explicitly identified your Load of Interest (Step 3). Now you’re on to Step 4- LOI circuit analysis. In this step, you’re tracing the power supply circuit for your Load of Interest. In the case a 240 VAC load, you’re reading the schematic to see how the load gets L1 and how it gets L2. For a 120 VAC load, you’re reading the schematic to see how the load gets Line and how it gets Neutral.

In this short little video from a Live Dojo workshop, we work through an example of tracing the power supply for a load of interest, in this case, the bake ignitor in a gas range. Watch and learn a few schematic reading tips to make your life easier.

Then we moved on to a discussion about the surprising power of the all-important but under-appreciated Problem Statement.

In our experience, many techs cannot formulate a focused, succinct and coherent problem statement. We see this every day at Appliantology. If you can’t come up with a SINGLE SENTENCE problem statement, it will impair your ability to fix the problem. If your thinking is fuzzy, your troubleshooting will also be fuzzy (and ineffective).

Your problem statement is a single sentence that answers one or both of these questions:

– What is the appliance doing that it SHOULD NOT be doing?

– What is the appliance NOT doing that it SHOULD be doing?

Ideally, your problem statement should include your load of interest (LOI)– “the thing that ain’t doing its thang”– by name.

So, let’s watch a little half hour video from a recent Live Dojo workshop where we “troubleshoot” problem statements posted at Appliantology by professional appliance techs.