How to check if a MOSFET is bad
We are going to explain to you how to check if a MOSFET is bad, and MOSFET is a common electronic component we used in most applications.
But most of us don’t know how to check a MOSFET and confirm them works well or is bad, in this article we are going to list some common MOSFET checking procedures using the multimeters.
Check if a MOSFET is bad
Before going to the checking procedure of MOSFET, we need to know some of the common failures that happen at MOSFET.
- One of the most common failures in MOSFET is the gate-source breakdown, this can easily determine by setting the multimeter in resistance mode.
- We know that MOSFET had a body diode internally, so we can check the body diode is faulty or not by connecting the multimeter into MOSFET’s source to drain terminals (resistance mode).
- And the MOSFET can handle high temperatures, the fault-finding due to temperature rising will be check with the diode mode of the multimeter.
- We need to set diode mode at multimeter to check diode, if a reading appears without any variation, the MOSFET is good.
- Or if the meter indicates zero, MOSFET is faulty.
- And also this process will be the same for all MOSFET types, but with different probe connections.
- We need to set the multimeter in resistance mode and connect the probes between the drain and source terminals of MOSFET.
- If a multimeter indicates high resistance, which is a clear indication for a good MOSFET.
- If the multimeter indicates zero, the MOSFET is faulty.
- We need to set the multimeter in continuity mode and connect the positive to drain and negative to the source.
- If the reading will be zero, with a buzzer sound, the MOSFET is faulty.