Removing A Dsimm - Sun Microsystems SPARCstation 4 110 Service Manual

Physically, dynamic random access memory (DRAM) chips are grouped in single in-
line memory modules (SIMMs) that plug into DSIMM slots located on the system
unit's main logic board. The SPARCstation 4 system board accepts industry-standard
JEDEC SIMMs, which are widely available from a number of different suppliers.
Sun Microsystems offers two different types of DSIMMs for these systems—an
8-megabyte DSIMM and a 32-megabyte DSIMM.
SPARCstation 4 system units come equipped with a minimum of 16 megabytes of
DRAM, expandable to 160 megabytes using 32-megabyte DSIMMs in all five slots.
Caution – DSIMMs installed in your system must have been specifically designed
to operate in it. Do not remove DSIMMs from a different Sun system and install them
in a SPARCstation 4 system.
Caution – A DSIMM is made of delicate electronic components that are extremely
sensitive to static electricity. Ordinary amounts of static from your clothes or work
environment can destroy a DSIMM. Handle a DSIMM only by the edges. Do not
touch the components on the DSIMM or any metal parts. Wear a grounding strap
before unpacking and during handling of a DSIMM. Do not disconnect the power cord
from the system unit's power receptacle. The power cord should be left plugged in to a
grounded power outlet. This connection provides the necessary ground path so that
you can safely remove and install DSIMMs and other components. Be sure that the
system unit power is in Standby mode. Check the green light-emitting diode (LED)
at the front of the chassis to be sure it is not lit.
11.3.1

Removing a DSIMM

1. Shut down and power off the system.
See Section 6.1 "Powering Off the System" on page 6-1.
2. Remove the cover and attach a wrist strap.
See Chapter 7.
3. Place an antistatic surface next to the system.
4. Locate the slot for the DSIMM you need to remove.
See
FIGURE 11-19
.
Chapter 11 System Board and Component Replacement 11-17