IBM BladeCenter QS20 Problem Determination And Service Manual page 71

Note: The cable is assymetric! You must plug the connector with two clamps
into the BladeCenter QS20 and the connector with only one clamp into
the adaptor card (with the clamp facing you), see Figure 15.
16. Fan out the cables and carefully bend them sidewards.
17. Connect the second connector of the PCI-Express cable to the InfiniBand card
adaptor. If you have installed the lower (second) InfiniBand option, be careful
not to damage the second card when you install the connector to the upper
card.
Figure 15. PCI Express connector installation (if you have installed the second InfiniBand
option)
18. Optional: repeat the above steps for the second InfiniBand option.
Note: When you install the lower (second) InfiniBand option, make sure that
the PCI-Express cable is not blocking the top cover.
19. Peel the back of the 8.75 inch gasket to expose the adhesive. Apply the
gasket to the QS20 cover as shown in the figure below. The gasket is applied
on the inside of the cover so that it rests on the edge of the front bezel.
Chapter 5. Installing and removing replaceable units
53