Position the two enclosure parts and carefully join the Raspberry Pi A+ GPIO header with the socket on the 3.5” PiTFT display. Double check to ensure the all pins are goin into the socket properly - Press them firmly together.
Insert four #4-40 3/8 flat Phillips into the bottom enclosure part with the recessed stand offs. Fasten until screw reaches through stand off.
Turn on the Powerboost 500C with the slide switch to test the circuit. The Raspberry Pi A+ should boot.