Apple TV/FM Radio System - Manual (Page 20)

13 Installing the Card and Software
4 Slide the TV/FM tuner card into place under the logic board
tray. Fit the edges of the card into both of the guides there,
making sure the notches on the card point upward.
Make sure the TV/FM tuner card slides
into the guides along the underside
of the sheet metal logic board tray.
Sheet metal logic board tray
Install the TV/FM tuner card with
these notches pointing upward.