Replacing an MCS in an M40e Router

The router can have an MCS in each of the slots labeled MCS0 and MCS1 at the rear of the chassis, as shown in Figure 1. Each MCS weighs approximately 2.5 lb (1 kg).

The MCSs are hot-pluggable, as described in M40e Field-Replaceable Units (FRUs). For a description of the effect of removing an MCS, see M40e Host Module Description. To replace an MCS:

Figure 1: Rear of M40e Chassis with Component Cover Removed

Removing an MCS from an M40e Router

To remove an MCS from an M40e router:

1. Place an electrostatic bag or antistatic mat on a flat, stable surface.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
3. Remove the rear component cover by loosening the thumbscrew at each corner of the cover and pulling it straight off the chassis. For complete instructions, see Removing Components from the Chassis Before Installing the M40e Router Without a Lift.
4. If two host modules are installed, use one of the following two methods to determine which is functioning as master:
   • Note which of the green host module MASTER LEDs is lit on the craft interface.
   • The master Routing Engine is designated Master in the Current state field when you issue the command:
     
     

     user@host> show chassis routing-engine

     Routing Engine status:      Slot 0:     Current state                 Master ...  

5. If the component you are removing belongs to the master host module and a second host module is installed, switch mastership to the standby host module by issuing the CLI command:
   
   

   user@host> request chassis routing-engine master switch
6. To halt the router:
   
   

   user@host> request system halt

   Wait until a message appears on the console confirming that the operating system has halted.

   For more information about the command, see the Junos OS System Basics and Services Command Reference.

   Note: The SFM might continue forwarding traffic for approximately 5 minutes after the request system halt command has been issued.

7. Push the end of each extractor clip (located at each end of the MCS) outward.
8. Grasp the extractor clips and slide the MCS about halfway out of the chassis.
9. Place one hand under the MCS to support it, slide it completely out of the chassis, and place it on the antistatic mat or in the electrostatic bag.

Figure 2: Removing an MCS from an M40e Router

Installing an MCS in an M40e Router

To install an MCS in an M40e router:

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. Place one hand under the MCS to support it and grasp one of the extractor clips on the faceplate with the other hand.
3. Align the rear of the MCS with the guides inside the chassis and slide it in completely.
4. Press the extractor clip at each end of the MCS inward.
5. Verify that the green LED labeled OK on the MCS faceplate is lit. Also check the host module LEDs on the craft interface to verify that the green LED labeled ONLINE is lit for the host module to which the MCS belongs (M40e Craft Interface Description shows the LEDs).

   You can also verify correct MCS functioning by issuing the show chassis environment mcs command described in Maintaining the M40e Host Module Components.

6. Reinstall the rear component cover and tighten the thumbscrew at each corner to secure it to the chassis. For complete instructions, see Reinstalling the M40e Components into the Chassis.

   Caution: To maintain proper airflow and provide electromagnetic shielding, do not operate the router without the rear component cover in place.

Figure 3: Installing an MCS in an M40e Router