Here is a simple example of what been happening to various pcbs when I play with them. I have an arduino powered by USB. Then a 5V and GND connected to a logic level shifter's HIGH and GND respectively. The VCC of the shifter is smoking and is hot. I cant understand why this is happening. I looked at the solder and it looks ok from the top and bottom of the pin. The board seems to work once the rest of the wires are connected. I stopped using it when I saw the smoke as I don't know where to go from here. What am i doing wrong?
https://www.sparkfun.com/products/12009 is the PCB of the shifter.
EDIT: added schematic from the fritzng EDIT: The intent was to drop the 5V IO to 3.3V to talk to a ESP8266. I didn't get that far when I saw the smoke.
Circuit diagram of the level shifter: