Single Inline Memory Modules (Simms); Determining Faulty Simm Locations - Sun Microsystems SPARCstation 2 Service Manual

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Single Inline Memory Modules (SIMMs)

Determining Faulty SIMM Locations

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SPARCstation 2 system units are equipped with a minimum of 16 megabytes of
random access memory (RAM). Physically, RAM chips are grouped together
in single inline memory modules (SIMMs). Each SIMM contains 4 megabytes
of memory and plugs into a SIMM slot located on the main logic board of the
system unit. Additional SIMMs may be added to the system unit as needed in
16-megabyte increments, up to a maximum of 16 SIMMs (64 megabytes).
SunOS, Sundiag System Exerciser, SunDiagnostic Executive, and POST
diagnostics can report memory errors encountered during program execution.
Memory error messages on the system monitor display usually include a
physical memory address of the error.
Depending on the diagnostic program you are running and the SunOS release
loaded, a SIMM location number ("U" number) may be displayed. If the
location number is present in the error message, follow the instructions later in
this chapter for removing the defective SIMM at that location and installing a
replacement (see Figure 4-7 for SIMM location numbers).
If the location number is not displayed but a physical memory address is
shown, refer to the following table to locate the SIMM bank in which the
defective SIMM is installed.
SPARCstation 2 Field Service Manual—February 1991