Connecting Mosfets

Hi
I am simply trying to switch a few leds on/off via a 2n7000 mosfet. The problem I have is when the gate is connected to ground the leds still glow a little. I have tried 3 brand new mosfets out of the bag all have the same problem.

I have source - ground, gate - ground, drain - cathode on leds.

Any ideas on what i'm doing wrong?

The 2N7000 can have an leakcurrent of 1uA and that could be enought to glow the LED.
Try to connect a resistor across the LED, 100kohm to 1 Mohm

Pelle

Were the devices in an anti-static bag? If not they could easily be damaged, these little
MOSFETs have no protection diodes and are much more static sensitive than logic
chips. Classic symptom of mild damage to a MOSFET is leakage current.

they glow quite brightly. Enough to light up the room slightly with only 1 led in.

Yes the mosfets were in an anti static bag but I did purchase them a few years ago.

My usage of them is correct?

I pulled some more out next one I tried works perfectly.
Cant explain why but some of them appear to be faulty, something has happened to them who knows.

At least ive read every damb article on connecting these things and hopefully ill never forget SOURCE goes to ground not the drain.

ahh I just figured out what I was doing wrong.

I was using what i thought was a 20k pulldown resistor I measured its resistance using my multimeter instead of reading the colours. I just connected it to this working transistor and now its also leaking current. Turns out its no resistor but an inductor! It must have somehow amplified the voltage on the gate when I pulled it high destroying the mosfet.

So it's actually trashing the fets, not just keeping them from working correctly while it's present?

I'm trying to think of a mechanism by which it could damage the fet without destroying the uC, I can't come up with anything...

the microcontroller is not connected. if it was im sure it would have been damaged too.