WARNING: These components MUST be installed in the correct orientation (see close-up below, right) - not only for proper operation, but for safety as well. Double-check orientation before soldering.
The two voltage regulators are identical, so either can be placed in their respective holes. The regulators are “programmed” to output the required voltages based on the values of each of the resistor pairs (R1, R2), and (R3-R4). For this reason, you must be certain you have installed your resistors correctly.