Mosfet test

[xboxhaxorz]

i am testing a mosfet, i set my MM to diode i put the neg on the source, the pos to the gate and i get OL. I touch the pos to the drain and i get 0.056 while holding both leads to the source and drain i touch it and it goes high and then instantly OL.

Is this a working or faulty mosfet?

i am testing a mosfet, i set my MM to diode i put the neg on the source, the pos to the gate and i get 0.782. I touch the pos to the drain and i get 0.520 while holding both leads to the source and drain i touch it and it doesnt change.

i assume this means its most def faulty?

thanks

[killian6pk]

Re: Mosfet test

My understanding is you need to test these with an Analog Multimeter with a X10K setting. The analog needle deflects instead of what your getting with the Digital OL. I will try and find the testing procedure and get back to you if someone does not beat me to it.

[momaka]

Re: Mosfet test

i am testing a mosfet, i set my MM to diode i put the neg on the source, the pos to the gate and i get OL. I touch the pos to the drain and i get 0.056 while holding both leads to the source and drain i touch it and it goes high and then instantly OL.

Let me recite to make sure I understand you correctly...
First you put negative probe on source and positive on drain.
Then you measure between source and drain with negative probe on source.
Finally, you touch Gate with your finger, thus discharging the MOSFET, and the resistance between source and drain goes infinite.

If so, the MOSFET should be good.

[xboxhaxorz]

Re: Mosfet test

Yes you understand correctly. So this mosfet works. For the 2nd mosfet i tested that would be a bad mosfet?

[xboxhaxorz]

Re: Mosfet test

My understanding is you need to test these with an Analog Multimeter with a X10K setting. The analog needle deflects instead of what your getting with the Digital OL. I will try and find the testing procedure and get back to you if someone does not beat me to it.

I am using this http://www.amazon.com/Sinometer-Manu...1200246&sr=1-2

but if i need an analog i will get it. I thought the diode setting would work for mosfets.

[momaka]

Re: Mosfet test

I made a big typo above... This:

First you put negative probe on source and positive on drain.

should be written like that:

First you put negative probe on source and positive on gate

For the 2nd mosfet i tested that would be a bad mosfet?

Can you be more specific? Which part of the test did the 2nd MOSFET fail? Are you measuring this in curcuit or out of circuit?

I am using this http://www.amazon.com/Sinometer-Manu...1200246&sr=1-2
but if i need an analog i will get it. I thought the diode setting would work for mosfets.

What you have should be fine.