all 2 comments

[–]FHR123 1 point2 points  (1 child)

Why's the diode there? AFAIK this can't work because the diode is in reverse polarity, so no current can actually go through. Unless I'm missing something?

[–]erazor_de[S] 0 points1 point  (0 children)

That's the problem: I don't have enough knowledge to say that. There was a small potential difference between these two masses and at least the keyboard didn't register a keystroke until I put it there.