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How to Determine if a Micro Switch Is Faulty or of Poor Quality?

May. 24, 2023

Micro switches are commonly used in various electronic devices and appliances due to their reliability and precision. However, like any mechanical component, they can experience faults or degrade in quality over time. It is crucial to identify whether a micro switch is faulty or of poor quality to ensure proper functioning of the associated device. In this guide, we will discuss several indicators and tests to determine if a micro switch is defective or of substandard quality.


Examine Physical Damage:

The first step in diagnosing a faulty micro switch is to visually inspect it for any signs of physical damage. Look for cracked or chipped plastic housing, bent or broken actuator arms, loose terminals, or any other visible signs of wear and tear. If the micro switch appears damaged, it is likely to be faulty and requires replacement.

Waterproof Micro Switch

Waterproof Micro Switch

Inconsistent Operation:

A reliable micro switch should exhibit consistent operation when the actuator is pressed or released. If you notice that the switch is sporadic or unreliable in its response, it may indicate a fault. Perform multiple actuations of the switch and observe whether it consistently engages or disengages as expected. Inconsistent operation can be a sign of worn-out internal components or poor contact within the switch.


Unresponsive Switch:

When pressing the actuator, a functional micro switch should respond promptly by activating or deactivating the associated function. If the switch fails to respond at all or requires excessive force to trigger, it is likely malfunctioning. An unresponsive micro switch may indicate issues with the internal spring mechanism or faulty electrical connections.


False Triggering:

A micro switch should only activate when the actuator is intentionally pressed or released. If you find that the switch triggers spontaneously or without any interaction, it is likely to be faulty. False triggering can result from poor internal contacts, misalignment of the actuator, or excessive sensitivity of the switch. Proper adjustment or replacement is necessary to rectify this issue.

Long Lever Micro Switch

 Long Lever Micro Switch

Audible or Physical Feedback:

Functional micro switches often provide a distinct clicking sound or tactile feedback when the actuator is pressed or released. If you notice a significant change in the audible or physical feedback of the switch, it may indicate a problem. A switch that feels mushy, loose, or lacks the characteristic clicking sound may be defective or of inferior quality.


Testing Electrical Continuity:

To assess the electrical functionality of a micro switch, you can use a multimeter to test the continuity across its terminals. Set the multimeter to the continuity or resistance mode and touch the probes to the terminals of the switch. Actuate the switch by pressing or releasing the actuator while observing the multimeter reading. If the multimeter does not indicate continuity or shows an inconsistent reading during actuation, the micro switch likely has an electrical fault.


Contact Resistance Measurement:

Another useful test is to measure the contact resistance of the micro switch. Excessive contact resistance can hinder the flow of current and compromise the switch's performance. Using a multimeter in the resistance mode, touch one probe to each terminal of the micro switch. A high resistance reading indicates poor contact and may signify a faulty switch.


Durability and Rating:

Consider the expected durability and rating of the micro switch for its intended application. If the switch fails prematurely or exhibits poor performance in relatively normal operating conditions, it might indicate a lower-quality component. Comparing the performance to the specifications provided by the manufacturer can help assess its overall quality.



Identifying faulty or non-conforming microswitches is essential to maintaining the reliability and functionality of electronic equipment and appliances. By conducting a visual inspection, assessing operational consistency, checking responsiveness, performing electrical tests and considering durability and ratings, you can determine if a microswitch is up to scratch.

TMAZTZ,founded in 1998, is a manufacturer focus on R&D and production of Industrial Control Switch, such as limit switches, micro switches, sealed switches, waterproof switches, toggle switches and foot switches.

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