A super handy appliance repair technique is “cheating” a load, which just means applying power directly to a load to check whether it is functional or not, independent of the switches, boards, and such that are in the load’s circuit.
This is often used during troubleshooting, where taking the time to test parts which are suspected of having failed can be the difference between guessing and knowing which part has failed. This avoids replacing an unneeded part, the subsequent awkwardness with the customer and a whole separate trip.
For example, you have a GE refrigerator where the evaporator fan has failed. Is it the fan motor itself or is it the board supplying power to the fan motor? You could and should check for valid supply voltage to the motor. But what if the motor is a three- or four-wire BLDC motor? In this case, having power voltage for the fan motor isn’t enough; you also need a digital speed signal from the board to the motor and/or digital RPM signal from the motor to the board.
There are also situations, like the one in the video below, where we want to double-check the health of certain loads before installing an expensive new control board.
Cheating a load is one of the troubleshooting techniques that we teach at Master Samurai Tech. Sometimes, it is expeditious to cut through the ambiguity of the other signals and just cheat the motor to see if is capable of running. Exactly how you power the load depends on the load itself.
In the video below, Samurai Appliance Repair Man shows you how to cheat one of those fancy multiwire BLDC motors using a 9 volt battery to make it run. A little schematic know-how and hot-wiring skills is all it takes. Come with me now on a Journey of Total Appliance Awareness™:
Learn how to troubleshoot by the Samurai’s Ten Step Tango troubleshooting system. We teach you that and much more in our world-famous Core Appliance Repair Training course. Enroll today!