IBM 9009-41A Manual page 95

Figure 72. Disconnecting the front SAS cables
6. Ensure that all cables are carefully positioned out of the way, such that the disk drive backplane can
be easily lifted and removed.
7. Carefully unscrew the captive thumbscrews (A) and (B) of the disk drive backplane until fully loose as
shown in the following figure.
If needed, use a Phillips screwdriver to loosen the screws.
Drive backplanes for the 9009-41A, 9009-41G, 9009-42A, 9009-42G, or 9223-42H 81