I'm having troubles with some mosfets I ordered, (4 * N-channel [30N06L], 4 * P-channel [27P06]).
When I first got them, every time you put voltage into a fet, it would randomly choose between turning a LED off, or slightly brighter (it was dim by default). Then after switching the fet (to another N-Channel), the gate wire stopped responding to the arduino (3.3v and 5v pins). However it would respond to the wires of battery; touching the positive turned it on (and it stayed on, even after removal), touching negative turned it off. I then uploaded the blink program, not surprisingly nothing happened. So I swapped drain and source around (I've read the datasheets, I know my original configuration was correct). Now, the led goes from dim to slightly brighter, every second, as the program specifies.
Here's a diagram:http://imgur.com/KcyDc
Why is everything being so weird? And how come it only now faintly changes?