Replacing the Fan on an NSM4000 Appliance
The NSM4000 appliance ships with two field-replaceable fans that are hot-swappable. You can remove and replace a fan without powering off the appliance or disrupting any functions.
When a fan fails, the full cooling load switches to the remaining fan and the red Hardware Fault LED on the front panel of the appliance blinks and an alarm sounds.
 | Note: The LEDs on the front panel of the NSM4000 are arranged vertically, as shown in Figure 1. |
Figure 1: NSM4000 Appliance Front Panel Status LEDs
1 — Power LED | 3 — Hardware Fault LED |
2 — Hard Disk Activity LED |
 | Caution: The NSM4000 appliance should not run on one fan for an extended period of time. Failed fans should be replaced as soon as possible. |
Ensure that you have the following parts and tools available to remove the fan from the appliance chassis:
- (Optional) Electrostatic discharge (ESD) grounding strap
- (Optional) An antistatic bag or an antistatic mat
Removing the Fan
To remove a fan from an NSM4000 appliance:
- (Optional) Place the antistatic bag or antistatic mat on a flat, stable surface.
- (Optional) Attach an ESD grounding strap to your bare wrist, and connect the strap to an external ESD point.
- Press the latch at the side of the fan, as shown Figure 2 to release the fan.
Figure 2: Removing a Fan
- Pull the fan module out of the chassis.
- (Optional) Place the fan module in the antistatic bag or on the antistatic mat placed on a flat, stable surface.
Installing the Fan
To install a fan in an NSM4000 appliance:
- (Optional) Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to an external ESD point.
- Remove the replacement fan module from its antistatic bag.
- Insert the replacement fan into the slot for the fan module,
as shown in Figure 3, until the latch locks and you hear a clicking sound.
Figure 3: Installing a Fan
When you install a replacement fan, the cooling load is distributed back evenly across both the fans, and the Hardware Fault LED stops blinking and the alarm turns off.
