19
e. Carefully install the optocoupler on the PCB. Double check to make sure the long LED lead is
in its correct hole -- with the square pad (51). Bend the leads out on the back, solder all four
leads and snip them (52).
51
52
11. Speaker: Place the speaker into its holes (53). The pin marked with a “+“ on the bottom of the
speaker goes into the hole marked “+.” Make sure it’s sitting flush to the top of the circuit board,
then solder the pins (54). Try not to use an excessive amount of heat on the pins; try not to let the
soldering iron tip linger on the pins longer than necessary.
53
54
55
