IBM Power System 9040-MR9 Manual page 69

Figure 56. Placing the heat sink on the TIM
e) Ensure that the heat sink load arms are engaged as shown by (A) in the following figure.
f) Tighten the center load screw clockwise by using the supplied hex key as shown by (B) in the
following figure until a firm stop is reached. If the heat sink moves noticeably, the load arms are
not engaged. Unscrew the center load screw and repeat this step again.
System backplane for the 9040-MR9 55