If you don’t have access to a multimeter, you may be able to visually inspect the MOSFET for any physical damage or signs of overheating, such as burnt or discolored areas on the surface. You can also check if the MOSFET is securely connected to the circuit, and if the surrounding components are working correctly.
Keep in mind that visual inspection is not a reliable way to test the functionality of the MOSFET, and it’s always recommended to use a multimeter or similar device to perform accurate measurements.
A specially designed circuit can able to do the job. The circuit will perfectly work with N channel mosfet. By simply insert the N channel mosfet to the the circuit and press the push button to check if the mosfet is good or bad.
N Channel Mosfet Testing Circuit
Components Required
- 47 uf/50v Cpacitor
- LED
- 10K resistor
- 1k Resistor
- Push button
- 12v power supply
- Dotted PCB
Working
Mosfet is connected to the LED legs to check the mosfet is working properly or not. If the mosfet is working properly the led will glow while pressing on the push button. The LED will turn off slowly when releasing the push button.
Mosfet source pin is directly connected to the negative polarity of the power supply. Drain pin to the led leg.
Gate pin is directly connected to the push button and a parallel connection of capacitor and 10k resistor. This will act as charging and discharging of gate voltage while pressing and releasing of push button.
