prongs

http://www.youtube.com/watch?v=Ny8JWejm2N8 I just bought 2 LEDs for the first time, and i put the clip on the 9v battery and I put the two wires on the two outside wires, and it smoked and turned off and only flashed blue, not all the colors. First: Is the longest prong in the middle negative...

I kinda borrowed an s video cord from my uncle, when I tried to put it back in his computer one of the four tiny prongs on the inside was crooked, i tried to bend it back but it snapped off, it still went in with just the three prongs, but will it work or should i buy a look a like before he...