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Removing a T1600 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. For more information about ESD, see T1600 Preventing Electrostatic Discharge Damage.
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.

Installing the T1600 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. For more information about ESD, see T1600 Preventing Electrostatic Discharge Damage.
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

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