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Cisco 2900 Series and 3900 Series Hardware Installation Guide
OL-18712-03
Chapter 5 Installing and Upgrading Internal Modules and FRUs
Installing and Removing DRAM DIMMs
Installing and Removing DRAM DIMMs
Remove the chassis cover or remove the SPE as described in the
“Accessing Internal Modules” section
on page 5-4
.
Caution
Always wear an ESD-preventive wrist strap and ensure that it makes good contact with your skin when
you remove or install DIMMs. Connect the equipment end of the wrist strap to the metal part of the
chassis.
Caution
Handle DRAM DIMMs by the edges only. DIMMs are ESD-sensitive components and can be damaged
by mishandling.
Locating and Orienting DRAM DIMM
Cisco 2901, 2911, and 2921 routers have a single DRAM DIMM socket on the system board. Cisco 2951
and Cisco 3900 series have two DRAM DIMM sockets on the system board that are identified as
DIMM 0 and DIMM 1. See the
“Locating Internal Modules” section on page 5-7
to find DIMM
connectors on the router.
DRAM DIMMs have a polarization notch on the mating edge to prevent incorrect insertion.
Figure 5-8
shows the polarization notch on a DRAM DIMM.
Caution
DIMMs and PVDM3s plug into similarly sized sockets. Only the polarization notch differs. Look for the
polarization notch shown in
Figure 5-8
before inserting a DRAM DIMM in the socket.
Figure 5-8
DRAM DIMM Showing Polarization Notch
1
Polarization notch
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