HP 98568A Installation Instruction page 28

HP 98568A Backplane Expander
4. Install the two flat cables received with the expander into the two
connectors on the top edge of the computer's four-slot backplane. Be
careful not to bend any of the pins in the connector. Press in until the
locking tabs lock across the back of the cable connector.
Figure 2-2.
Installing the Two Cables
5. Bend the cables so that the free ends point upward.
6. Loosen the two captive screws securing the expander power supply access
door and remove the access door.
7. Slide the computer top cover toward the rear of the computer. Then spring
the sides out and up and lift it off.
8. Place the expander upside-down on a flat, solid surface.
2-4 Adding Expanders