IBM Power System Series Manual page 118

Figure 92: Placing the system into the operating position
f) Secure the disk drive backplane with two recessed screws at (A). Use a 4 mm ball-end hex driver
(130 mm long, IBM part number 02EA546) to tighten the screws.
First, set the screw threads on one side, then the other. Then, evenly tighten the screws on both
sides until both sides are seated. If you screw in one side of the disk drive backplane completely,
the disk drive backplane might twist, preventing the disk drive backplane from properly seating in
the chassis.
g) Secure the disk drive backplane with two screws at (B).
114 Power Systems: Temple's Zeppelin procedures for install, remove, replace