Apple PowerBook (Duo 270C) - Manual (Page 252)

18. Tighten the screws you loosened in step 5.
The screws are spring-loaded. You’ll need to exert strong
downward pressure while you turn them clockwise.
19. Reconnect the power supply cable you disconnected in
step 4.
20. Replace the dock cover.
Align the cover over the base, press down firmly on the rear
corners, and then press down on the front corners until the
latches click.
See the information that came with your NuBus card for
information about its accompanying software (if any) and use.
236 Chapter 13: Building a PowerBook Duo System