This article explains the procedure to replace MX960 fan tray.

Fan tray replacement is required sometimes because of faulty hardware.

Following alarm is observed.

root@device> show chassis alarms

1 alarms currently active

Alarm time Class Description

2025-01-04 02:00:42 -06 Major Top Fan Tray Failure

Please follow below steps to replace a FAN TRAY in MX960:

Removing an MX960 Fan Tray

Note: To prevent overheating, install the replacement fan tray immediately after removing the existing fan tray.

To remove the upper or lower fan tray :

1. Attach an ESD grounding strap to your bare wrist, and connect the other end of the strap to an ESD grounding point.

2. Reposition the standard cable manager before removing the lower front fan tray:

Note: This step is not required for the extended cable manager.

a) Unwrap any cables on the standard cable manager and remove the cables from the tray. Arrange the cables so that they do not block the front of the cable manager and tray, and secure them with temporary fasteners so that they are not supporting their own weight as they hang from the connector.

b) Simultaneously pull the two releases labelled PULL on the cable manager. Lift it up and outward to lock it in place.

3. Loosen the captive screw on each side of the fan tray faceplate.

4. Grasp both sides of the fan tray, and pull it out approximately 1 to 3 inches.

Warning: To prevent injury, keep tools and your fingers away from the fans as you slide the fan module out of the device. The fans might still be spinning.

5. Pause for approximately 15 seconds to allow the fans to stop spinning.

6. When the fans stop spinning, press on the two latches located on the inside of the fan tray.

7. Place one hand under the fan tray to support it, and pull the fan tray completely out of the chassis.

Installing an MX960 Fan Tray

To install a fan tray :

1. Attach an ESD grounding strap to your bare wrist, and connect the other end of the strap to an ESD grounding point.

2. Grasp the fan tray on each side, and insert it straight into the chassis. Note the correct orientation by the "this side up" label on the top surface of the fan tray.

3. Tighten the captive screws on each side of the fan tray faceplate to secure it in the chassis.

4. Lower the cable manager back into position, if necessary.

Please refer below Techpub for more details :

https://www.juniper.net/documentation/us/en/hardware/mx960/topics/task/fan-tray-mx960-replacing.html