Replacing a T640 Routing Engine

To replace a Routing Engine, perform the following procedures:

1. Removing a T640 Routing Engine
2. Installing a T640 Routing Engine

Removing a T640 Routing Engine

1. Take the host subsystem offline as described in Taking the T640 Host Subsystem Offline.

   Caution: Before you replace a Routing Engine, you must take the host subsystem offline. If the Routing Engine to be replaced is currently functioning as the master Routing engine, switch it to be the backup before taking the host subsystem offline. If there is only one host subsystem, taking the host subsystem offline shuts down the router.

2. Place an electrostatic bag or antistatic mat on a flat, stable surface.
3. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
4. Loosen the captive screws on the corners of the Routing Engine cover.
5. Grasp the Routing Engine cover by its edges, and pull it free from the chassis (see Figure 1).
6. If applicable, loosen the screws on the extractor handles at either end of the Routing Engine faceplate, using a Phillips screwdriver.
7. Press the red tabs on the ejector handles on both sides of the Routing Engine faceplate.
8. Flip the ejector handles outward to unseat the Routing Engine.
9. Grasp the Routing Engine by the ejector handles, and slide it about halfway out of the chassis.
10. Place one of your hands underneath the Routing Engine to support it and slide it completely out of the chassis.
11. Place the Routing Engine on the antistatic mat.
12. If you are not replacing the Routing Engine now, reinstall the Routing Engine cover and tighten the screws on the corners of the cover to secure it to the chassis (see Figure 4).

Figure 1: Removing the Routing Engine Cover

Figure 2: Removing a Routing Engine

Installing a T640 Routing Engine

To install a Routing Engine (see Figure 3):

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
2. Ensure that the ejector handles are not in the locked position. If necessary, press the red tabs and flip the ejector handles outward.
3. Place one hand underneath the Routing Engine to support it. With the other hand, grasp one of the ejector handles on the faceplate.
4. Carefully align the sides of the Routing Engine with the guides inside the chassis.
5. Slide the Routing Engine into the chassis until you feel resistance, then press the Routing Engine's faceplate until it engages the midplane connectors.
6. Press both the ejector handles inward to seat the Routing Engine.

   The Routing Engine might require several minutes to boot.

   If the router is powered on and the Routing Engine's corresponding control board is functioning normally, the Routing Engine comes online automatically.

7. If applicable, tighten the screws on the extractor handles, using a Phillips screwdriver. Be sure to tighten the screws enough to seat the Routing Engine properly.
8. Press the Routing Engine cover into place, then tighten the captive screws on the corners of the cover to secure it to the chassis (see Figure 4).
9. Verify that the Routing Engine is installed correctly.
   • Check the HOST0 and HOST1 LEDs on the craft interface. If the router is operational and the Routing Engine is functioning properly, the green OK LED lights steadily. If the red FAIL LED lights steadily instead, remove and install the Routing Engine again. If the red FAIL LED still lights steadily, the Routing Engine is not functioning properly. Contact your customer support representative.
   • Check the status of the Routing Engine, use the CLI command:
     user@host> show chassis routing-engine

   For more information about using the CLI, see the Junos OS manuals.

Figure 3: Installing a Routing Engine

Figure 4: Reinstalling the Routing Engine Cover