Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 

Replacing a T4000 SCG

 

  1. Removing a T4000 SCG

  2. Installing a T4000 SCG

Removing a T4000 SCG

The router can have one or two SCGs installed. The SCGs are located in the upper rear of the chassis, above the control boards and Routing Engines. Each SCG weighs approximately 1.9 lb (0.9 kg).

A nonredundant SCG is hot-pluggable. For redundant SCGs, the master SCG is hot-pluggable. The backup SCG is hot-removable and hot-insertable if the master SCG is functioning. Removing the backup SCG does not affect the functioning of the router. Taking the master SCG offline might result in a brief loss of SONET clock lock while the backup SCG becomes the master.

To remove an SCG (see Figure 1):

  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. Press the online/offline button on the SCG faceplate, and hold it down until the LED goes out (about 5 seconds).
  4. Loosen the captive screws on the edges of the SCG faceplate.
  5. Grasp the SCG by the handle on the faceplate, and slide it out of the chassis.
  6. Place the SCG on the antistatic mat.
Figure 1: Removing an SCG
Removing an SCG

Installing a T4000 SCG

To install a replacement SCG (see Figure 2):

  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. Carefully align the sides of the SCG with the guides in the SCG slot.
  3. Grasp the SCG by its handle, and slide it straight into the chassis until it contacts the midplane.
  4. Tighten the captive screws on the corners of the SCG faceplate.
  5. To bring the SCG online, press the online/offline button until the green OK LED lights.
  6. To verify that the SCG is installed correctly and is functioning normally, check the LEDs on the SCG faceplate. The green OK LED should light steadily. If the SCG is master, the blue MASTER LED should also light steadily.

    To check the status of the SCGs, use the following CLI command:

    user@host> show chassis environment scg
Figure 2: Installing an SCG
Installing an SCG

Related Documentation