Four inspection methods find the cause of thermistor failure

1. Observe the appearance of the thermistor. The potentiometer or thermistor should be clearly marked, and the solder pads or pins should not be rusted. The rotation of the rotary shaft is flexible, the elasticity is proper, and the hand feels smooth when turning. Whether there is mechanical noise and jitter.

2. Use your hand to gently shake the potentiometer pads or the pins of the thermistor, there is no looseness.

3. Turn the multimeter's electrical barrier to the proper range, and then perform ohm zero adjustment. Use two test leads (no difference between positive and negative) to connect the two ends of the resistor, so that you can measure the actual resistance value. Check the test value with the nominal value of the resistor, so that you can judge whether the potentiometer or thermistor is intact. If the pointer of the multimeter is not moving, then the internal resistor body is disconnected.

4. The middle pin of the potentiometer or thermistor is connected to the movable contact inside it. We use the two test leads of the multimeter to connect the middle pin and any of the remaining pins, and then slowly rotate the shaft handle. The pointer of the meter needs to move smoothly and correspondingly. If the pointer jumps or falls, then it means that The contact between the movable contact point and the resistor is problematic.