Both fan units must always be in place, even if one is not functioning properly, to
maintain proper cooling.
Use the following procedure to replace a hot-swap fan:
1. Check the LEDs on the back of the storage server.
2. If the amber Fault LED is on, remove the fan CRU that has failed.
a. Slide the latch to unlock the fan CRU.
b. Use the handle (black knob) to pull the fan from the storage server. See

Figure 65.

3. Install the new fan unit.
a. Place the fan CRU in front of the fan slot.
b. Hold the latch open, and slide the fan all the way into the slot. If the fan
does not go into the bay, rotate it 180°. Ensure that the latch is on the side
closest to the center of the storage server.
c. Release the latch. If the lever remains open, pull back on the fan slightly,

and then push it in again until the latch snaps into place.

4. Check the LEDs.
The Fault LEDs turn off after a few seconds. If they remain on, see Chapter 6,

“Hardware maintenance,” on page 111.

Working with power supplies
The power supply CRUs provide power to the internal components by converting
incoming ac voltage to dc voltage. The DS4100 base storage server power system
operates with two power supply CRUs that can be hot-swapped. In the DS4100
base storage server, one power supply CRU can maintain electrical power to the
unit if the other power supply is turned off or malfunctions. The power supply CRUs
are interchangeable (by reversing the locking levers).
The DS4100 single-controller storage server has only one power supply CRU. You
cannot remove or replace a working (non-failed) power supply in the DS4100
single-controller storage server without first powering down the storage subsystem.
Before you replace the power supply in the DS4100 single-controller storage server,
all I/O activity must be stopped and the storage server must be powered down. Go
f10ug038

Figure 65. Removing a fan

Chapter 5. Installing and replacing components 89