Sun Microsystems SPARCstation 20, Руководство по обслуживанию

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Chapter 11 System Board and Component Replacement 171
System Board
The following sections describe how to remove and install the system board, and
verify jumper settings
Removing the System Board
1. Remove power from the system.
See “Removing Power from the System” on page 45.
2. Remove the cover and attach the wrist strap.
See
FIGURE 11-33
.
Caution – Use proper ESD grounding techniques when handling components. Wear
an antistatic wrist strap and use an ESD-protected mat. Store ESD-sensitive
components in antistatic bags before placing it on any surface.
3. Remove the following:
■
MBus modules (see “MBus Module” on page 143)
■
SBus cards (see “SBus Card” on page 152)
■
SIMMs (see “DSIMMs, VSIMMs, and NVSIMMs” on page 159)
■
AVB (see “Auxiliary Video Board” on page 168)
■
NVRAM/TOD (see “Removing a NVRAM/TOD” on page 180)
Note –
The NVRAM/TOD contains system configuration parameters, the Ethernet
address, and host ID numbers. Install the removed NVRAM/TOD on the
replacement system board to preserve this information.
4. Disconnect the following from the system board (
FIGURE 11-36
):
■
Diskette connector (optional)
■
SCSI connector
■
DC power connector
■
Speaker/LED connector