IBM DS3950, Installation, User'S, And Maintenance Manual, Page: 179 / 252

Replacing a midplane
Statement 5:
CAUTION:
The power control button on the device and the power switch on the power
supply do not turn off the electrical current supplied to the device. The device
also might have more than one power cord. To remove all electrical current from
the device, ensure that all power cords are disconnected from the power source.
1
2
Attention: Observe handling static-sensitive device precautions stated in
“Handling static-sensitive devices” on page 29 when removing components.
Before you begin, ensure that you wear an anti-static wrist strap.
Perform the following steps to replace a midplane:
1. Complete the power-off sequence described in “Turning off the storage
subsystem” on page 109 to make sure that the DS3950 storage subsystem is
turned off before any attached storage expansion enclosures.
Attention: The power switch on the power supply and fan unit does not
turn off the electrical current supplied to the device. The DS3950 storage
subsystem might also have more than one connection to power. To remove all
electrical current from the device, make sure that all power cords are
disconnected from the power supply and fan unit input connectors.
2. Label and remove the power cords from the power supply and fan units of
the DS3950 storage subsystem.
3. Label the Fibre Channel cables that are attached to the rear of the controllers.
Labeling the cables simplifies the re-cabling process.
4.
Remove the Fibre Channel cables that are attached to the rear of the
controllers.
5. Remove both controllers. To remove them do the following:
a. Squeeze the controller latch and pull the lever open 90° (so that the lever
is horizontal) to release the controller from the latch. The controller latch is
a coral colored tab on the lever.
Note: The lever rotates upward or downward 90°, depending on whether
the controller you are removing is the right or left controller CRU.
b.
Slowly pull the lever away from the storage subsystem chassis to remove
the controller from the controller bay, as shown in Figure 15 on page 38.
(Remove the controllers from the chassis and place it on electrostatic
discharge (ESD) protected surface.)
c. Repeat steps 5a and 5b for the other controller.
6. Remove both power supply and fan units. To remove them, do the following:
Chapter 5. Replacing components
151