Place your replacement hard drive or solid-state drive into the caddy.

Make sure the drive is upside with the connector's golden pins facing up like so.

Also be sure the connector is facing away from the black tape handle. This and the above point will ensure proper connection to the Playstation 4.

If installing a solid-state drive, make sure the screw holes of the sled and the drive are aligned properly before screwing back in.

This isn't a problem with 2.5" hard disk drives since the thickness allows for proper alignment during placement.