3Com Router 6000 FamilyInstallation ManualChapter 6Maintaining Hardware3Com Corporation6-46.4.2 Installing the RPU2Step 1: Power off the switch or power switches if two PSUs are installed.Step 2: Align the edges of the RPU2 with the guides in the RPU2 slot and push the card insidethe router. Pull the ejector levers at both side of the RPU2 inward until they form the smallestdegree with respect to the RPU2 panel.Step 3: Fasten the captive screws on the RPU2.Step 3: Power on the router and check that the RPU2 LED is blinking.6.5 Replacing the SDRAMThis section describes how to replace an SDRAM (Synchronous Dynamic Random AccessMemory) module. SDRAM modules can be replaced on the RPU only. Memory on the RPU2cannot be replaced. The following flowchart provides an overview of the SDRAM replacementprocess.EndRemove the RPULocate the SDRAMon the RPURemove the SDRAMInstall the RPUPrepare toolsStartEndRemove the RPULocate the SDRAMon the RPURemove the SDRAMInstall a new SDRAMReplace the RPUPrepare toolsStartEndRemove the RPULocate the SDRAMon the RPURemove the SDRAMInstall the RPUPrepare toolsStartEndRemove the RPULocate the SDRAMon the RPURemove the SDRAMInstall a new SDRAMReplace the RPUPrepare toolsStartFigure 6-4 SDRAM maintenance flowSDRAMs are main board memory components that you can expand or upgrade as needed.Generally, you need to do that in the following situations:z More memory is required for the upgraded application image, maintaining a largerouting table, or processing tasks that consume large memory.z The existing SDRAM is damaged.