Replacing DRAM Modules

The DRAM installed on the Routing Engine provides storage for the routing and forwarding tables and for other Routing Engine processes. The design of the Routing Engine allows you to modify the DRAM configuration by adding DRAM modules to the system board, or removing DRAM modules from the board.

The DRAM modules are located on the top of the system board, as shown in Figure 73 and Figure 74. Two pairs of slots are available for installing DRAM modules. Installing DRAM modules in slots away from each other provides better performance than installing them in two adjacent slots.

Note: Use only DRAM modules purchased through Juniper Networks specifically for your model.

Figure 73: J2320 and J2350 DRAM Location

Figure 74: J4350 and J6350 DRAM Location

To modify the DRAM configuration, use the following procedures:

• Removing a DRAM Module
• Installing a DRAM Module

Removing a DRAM Module

To remove a DRAM module:

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 the ESD point on the chassis, or to an outside ESD point if the router is disconnected from earth ground. For more information about ESD, see the Getting Started Guide for your router.
3. Press and release the power button to power off the router. Wait for the POWER LED to turn off.
4. Unplug the power cord or cable from the power source receptacle.
5. Remove the screws from the sides and top of the chassis that secure the cover to the chassis.
6. Slide the cover off the chassis. (For J2320 and J2350 routers, see Removing and Replacing the Chassis Cover on J2320 and J2350 Routers.)
7. To release the DRAM module, press the plastic ejectors on both sides of the module (see Figure 75).
8. Grasp the DRAM module, being careful not to touch any electrical components on the module, and firmly pull it out of the slot on the system board.
9. Place the DRAM module on the antistatic mat or in the electrostatic bag.

Figure 75: Installing or Replacing DRAM Modules

Installing a DRAM Module

J2320, J2350, J4350 and J6350 Services Routers support 256-MB and 512-MB DRAM modules. Use only DRAM modules purchased from Juniper Networks specifically for your model.

Note: If you are installing a second DRAM module, do not install it in a slot adjacent to the first module. For example, if the first DRAM module is installed in slot 1, install the second module in slot 3 (see Figure 73 and Figure 74).

To install a DRAM module:

1. Take the following steps if you have not already done so:
   1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and connect the strap to the ESD point on the chassis, or to an outside ESD point if the router is disconnected from earth ground. For more information about ESD, see the Getting Started Guide for your router.
   2. Press and release the power button to power off the router. Wait for the POWER LED to turn off.
   3. Unplug the power cord or cable from the power source receptacle.
   4. Remove the screws from the sides and top of the chassis that secure the cover to the chassis.
   5. Slide the cover off the chassis. (For J2320 and J2350 routers, see Removing and Replacing the Chassis Cover on J2320 and J2350 Routers.)
2. Remove the DRAM module from its electrostatic bag.
3. Press the plastic ejectors on both sides of the DRAM slot to open it (see Figure 75).
4. Grasp the DRAM module by the edges, being careful not to touch any electrical components.
5. Pressing firmly on both ends, push the module into the slot until the ejectors click into the closed position (see Figure 75).
6. Slide the cover onto the chassis.
7. Replace and tighten the screws on the sides and top of the chassis that secure the cover to the chassis.
8. Replace the power cord or cable.
9. Press and release the power button to power on the router. Verify that the POWER LED lights steadily.
10. To view the DRAM configuration and verify that it was installed correctly, issue the show chassis routing-engine command, described in the JUNOS System Basics and Services Command Reference. This command shows the total memory installed.