How can i check a mosfet by using multimeter

If the LED glows only on pressing of the button, then your mosfet is fine, any other results will indicate a bad or defective mosfet. If you have any circuit related query, you may interact through comments, I'll be most happy to help! Your email:. I cant have any institute in my country i need your help to give me some of method to be able to repair any device. Rajesh, a mosfet will mostly burn due to a short circuit at the output, connect a fuse in series with the battery to verify the issue….

What do you think am doing wrong. I guess the pins are not in the above order. You can reply through my email if you wish Sir. Just now I checked the IRF as per the above explained instructions and I could check it perfectly, I will the upload a video soon for everybody. First you say short the gate and the drain to reset, then you say short the gate and the source to reset. Hello, We have extend this offer for you to provide us with a price quote for the item listed below:.

Thank you. Wabash Chicago, IL Doing the test on a NPN Mosfet, I have the continuity between source and draing after having charged the gate but this configuration is quickly within few seconds going to a open configuration, without touching anything. My understanding is that there is a parasitic resistance that discharge the gate and thus Mosfet is faulty. Could you confirm my understanding? For notice, my NPN Mosfet has an integrated zener diod protection.

You may be right, because any other result than the explained one indicates a faulty MOSFET, you can further confirm this using the LED jig circuit as shown at the bottom section of the article.

The pic you have shown above is wrong its shown source as middle pin but its drain instead you can confirm and thank me. Which pic are you referring to? The last two pictures indicate the wire connections only, not the pin orientation. Dear sir Thank you so much for the above simple circuit. Cramming the above 7 steps can be challenging when one needs speedy solution to a circuit problem. I would like you showcase steps for analog testing.

Please is there such a simple circuit for testing inductance and capacitance. I have one inductor i got from scrab which i want to use in a circuit but couldnt find the value on its body. Patrick, inductance meter and capacitance meter circuits are already published in this website, please use the search box to find them.

Can you update it please? The lower diagram is for p channel, the LED polarity are indicated in this diagram. The upper diagram is for N channel mosfet, the LED pin on the drain side will have negative polarity.

Really narration is too good with very simple English and very simple schematic diagrams too. I would love to read the articles when ever I face problem in solving circuits. Hello Turan, Glad you found the article helpful! Yes any equivalent mosfet will work. Your email address will not be published. The following are some of the fundamental steps of conducting the resistance test:.

In turn, it prompts the drain to source resistance to go very low. Nonetheless, there are some precautions that you need to take. The threshold voltage should be within the range of the multimeter for optimum performance. A faulty one can potentially bring loads of issues to the circuit. Thus, you are free to use any of the above techniques. Any of these methods should work for you effectively without any hitch. Contact us , and our team of experts will respond to your queries in the shortest possible time.

We are here to help you. File Upload. Submit Form. Home - Blog. Conduct a diode test. This operation will require a multimeter with diode mode. Resistance test. In this connection, the body diode is in forwarding bias mode. While in this mode, the multimeter should indicate a reading between 0. Reverse the probe connections to create an open circuit. The multimeter should not give any reading in this mode since the diode is now in reverse bias.

If the multimeter indicates any reading different from zero, the device is faulty. The following are some of the fundamental steps of conducting the resistance test: A well-functioning MOSFET should indicate a high drain to source resistance irrespective of the connection of the ohmmeter probes.

The polarity of the connection is therefore inconsequential on the outcome of the test. You can also use an ohmmeter instead of a multimeter to check the drain to source resistance. Put the multimeter on resistance mode to initiate the test. You should obtain a reading indicating an extremely high resistance. If you find that the value of the resistance reading is less than what is on the datasheet or zero, it is faulty.

The meter or ohmmeter should show the resistance which is on the datasheet. Figure 9: Different models of MOSFETs The following are some of the key steps when performing this test: Use the resistance test to identify the drain to source resistance. You will use this value for reference in the next step. You will do this by first ensuring that the multimeter is in diode mode.

You should expect a very low value reading on the ohmmeter, which tends to zero in this step. You can use a finger or a jumper wire. Lastly, you need to test the drain to source resistance using the resistance technique. This reading should be similar to the prior reading of the device in off condition.