Identify the bare Control Board PCB. It has part number TD-UCSE-D-CB printed on its bottom side.

For ease of access to the solder pads, place and solder the four through-hole components H1-4 before continuing this process.

Do not solder any of the following components yet.

Place the spacer onto switch component S1.

Place the combined spacer and switch onto the Control Board.

Place the four spacer components DS1-4 onto LED components D1-4.

Place the four combined spacers and LEDs onto the Control Board.