Apple Video System - Manual (Page 19)

12 Swing the wire handle on the logic board back up into its
storage position, securing it under its catch. Then fit the
logic board into the guide rails on both sides of the
computer’s interior.
Make sure the logic board slides
into the guides that are on both
sides of the computer’s interior.
Swing the handle up, into its storage position.
13 Installing the Card and Software and Connecting Video Equipment