Removing an M120 Routing Engine
The router can have one or two Routing Engines. They are located within the CB in the rear of the chassis on either side of the FEBs in the slots marked CB0 and CB1. Each Routing Engine weighs approximately 2.4 lb (1.1 kg).
 | Caution: Before you replace a Routing Engine, you must take the host subsystem offline. If there is only one host subsystem, taking the host subsystem offline shuts down the router. See Taking the M120 Host Subsystem Offline. |
| Caution: If the Routing Engine to be replaced is currently functioning as the master Routing engine, switch it to be the backup before removing it. See Taking the M120 Host Subsystem Offline. |
To remove a Routing Engine from a CB (see Figure 1):
- Take the host subsystem offline as described in Taking the M120 Host Subsystem Offline.
- Place an electrostatic bag or antistatic mat on a flat, stable surface.
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Press the red tabs on the ejector handles on both sides of the Routing Engine faceplate.
- Flip the ejector handles outward to unseat the Routing Engine.
- Grasp the Routing Engine by the ejector handles and slide it about halfway out of the chassis.
- Place one hand underneath the Routing Engine to support it and slide it completely out of the chassis.
- Place the Routing Engine on the antistatic mat.
Note: To maintain proper airflow through the chassis, do not leave a CB installed in the chassis without a Routing Engine for extended periods of time. If a Routing Engine is removed, a replacement Routing Engine should be installed as soon as possible.
Figure 1: Removing an M120 Routing Engine
