The LED is NOT symmetrical and must be oriented correctly.

Insert the LED leads about halfway into the front of the board, with the longer leg in the hole labeled "Long Leg," and the shorter leg in the hole labeled "Short Leg."

One edge of the LED's clear epoxy lens is flat instead of round. This flat edge indicates the negative (-) lead.

Push the LED towards the board (bending the leads) so the lens fits in the notch between the words "Let Your" and "Light Shine" on the top/front of the circuit board.