Apple Power Macintosh 7500 Series - Manual (Page 159)

11 Replace the cover on the computer.
Lower the cover all the way down onto the case, leaving a 2-inch gap. Push
the cover back until it snaps into place.
You are now finished installing the card. You may turn on the computer and
start using the new card.
WARNING Never turn on your computer unless all of its internal and
external parts are in place. Operating the computer when it is open or
missing parts can be dangerous, and can damage your computer.
Slide the top cover all the way back
until it snaps into place.
Set the top cover down so that there is about a two-inch
gap between the back of the top cover and the back of
the chassis.
149 Installing an Expansion Card