Who knows how to test N-Ch. MOFETS with Multimeter? Please HELP!

[Martin Rodriguez]

Let me start by saying that I'm having difficulty trying to test my NTE 2989 N-Ch MOSFET or any N-CH. MOSFETS. I'm testing with my digital multi-meter I followed this testing tutorial on YouTube, but didn't got the same results.

Intead of me doing a video conducting the MOSFET test, I instead created two images of tests I conducted. Look at the images below. My meter says that the MOSFET is defective, but look at the image where I tested it by apply 12V DC to an LED which this tells me that the MOSFET is good. Please help me why on my meter it says its bad and when apply voltage it works.

NOTE! I used 3 Digital multi-meters and no luck.

 

[Audioguru]

A Mosfet needs a few volts or more gate to source to turn on. But a digital multimeter measuring Ohms gives only 0.2V which is way too low. An old analog multimeter might use a 9V battery to test resistance.
Of course the test with the 12V shows that the Mosfet is normal.

 

[Bluejets]

I tend to use an old analog meter on Rx1 for tests like this.

 

[(*steve*)]

Or the diode check range which has a higher open circuit voltage.

 

[Bluejets]

I've seen a couple of those that will not work, perhaps not high enough bias voltage.
LED and a battery seems to work but I'd be inclined to use a resistor on the LED.

 

[Audioguru]

On Ohms, my fluke multimeter can make a germanium and a Schotky diode conduct but not a silicon diode nor transistor junction conduct. On diode test it has enough voltage to faintly light a 1.8V red LED but not a 3V blue nor white LED. I haven't tried testing a Mosfet because its threshold voltage of 2V to 4V is too high for my multimeter to cause a 3V to 4V Mosfet to turn on.

 

[Martin Rodriguez]

Would you'll say that testing on the breadboard by applying a 12v DC would be the best way to test MOSFETS instead of using my multimeter?

 

[Audioguru]

Would you'll say that testing on the breadboard by applying a 12v DC would be the best way to test MOSFETS instead of using my multimeter?

It is much better than using a digital multimeter that does not produce enough voltage to turn on a Mosfet.