IBM TotalStorage 300 Service Manual page 119

The fans are interchangeable and customer replaceable and do not require
preventive maintenance. The fans help maintain proper air circulation across the
components inside the storage unit. Air flows through the storage unit from the front
to the back.
You can hot-swap the fans (replace them while the storage unit is turned on and
running), as long as you complete the exchange within 10 minutes. This time limit
applies only to the total time that a fan is out of the storage unit, beginning when
you remove the failed unit and ending when you reseat the new one. This does not
include the time it takes you to perform this entire procedure (checking LEDs,
unpacking the new fan, and so on).
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 unit.
2. If the amber Fault LED is on, remove the failed fan.
a. Slide the latch to unlock the fan CRU.
b. Use the handle (black knob) to pull the fan from the storage unit.
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 unit.
c. Release the latch. If the lever remains open, pull back on the fan slightly,
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, refer to the
User's Reference.
Chapter 5. Installing and replacing IBM NAS 300 components
109