332Chapter 25 Replacing or installing a cooling fan

7Test the direction of the fan exhaust air flow to determine if the fan is correctly installed.

a Hold a piece of paper or your hand close to the fan exhaust. A correctly installed fan blows air away from the main unit.

b If the fan exhaust air flow is incorrect, remove the cooling fan (see “Removing a BCM200 cooling fan” on page 329) and reinstall the fan in the correct orientation (this procedure).

Removing an expansion unit fan

The BCM expansion unit comes either with one fan or a redundant fan set. The single-fan unit is not upgradeable.

Warning: Protect the hardware components against damage from electrostatic discharge. Always wear a grounded wrist strap before you handle components. Always place the components in a static-free container.

To remove an expansion unit fan

1Shut down the system (see “Performing a system shutdown” on page 231).

2Disconnect the fan power cable from the hub card.

Note: If the unit has redundant fans, each fan has a connector on the hub board.

3Locate the screws that fasten the fan casing to the expansion unit back wall and remove them. Refer to Figure 187 on page 333 and Figure 188 on page 333.

4Remove the four screws (or snap rivets) that hold the fan to the expansion unit.

5Lift the failed fan out of the expansion unit.

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Nortel Networks 400 4.0, BCM200 manual Removing an expansion unit fan, To remove an expansion unit fan