Potentiometers in household appliances are prone to malfunction after a period of use due to frequent use (e.g., volume potentiometers in radio recorders are often rotated repeatedly). The fault of potentiometer is easy to be shown on the whole machine, such as the noise when rotating potentiometer is very big, the sound is big and small, the power switch is out of order, and so on, then it is necessary to maintain the potentiometer.

After a period of application of carbon film and synthetic carbon film potentiometer, the most likely fault is high noise (especially non-sealed belt switch potentiometer), the main reason is that there is grease between the contact reed and the reed of the outlet terminal, or the resistance film is worn so that the contact resistance is unstable. At this time can be repaired by the following steps:

1. Pry open the metal shell of the potentiometer with the screwdriver and remove the metal shielding shell;

2. Use tweezers to clip cotton balls dipped in water and alcohol (or high-grade gasoline), gently wipe the resistance plate to remove toner and dirt generated by friction, and then use small cotton balls to remove oil stains at the connection between the contact reed and the extraction reed. Some potentiometer contact reed bakelite frame can be removed from the rotating shaft soil, so that it is easier to remove reed and resistance on the oil and toner;

3, after the completion of cleaning according to the original steps installed, repair work is completed.

These repairs do not always work. Worn potentiometers need to be replaced. It is better to choose the original model and original resistance potentiometer when replacing, and should pay attention to the length of the potentiometer shaft and its section shape, should be able to cooperate with the original knob. When the original model and original resistance potentiometer cannot be found, the appropriate model can be used instead.