System Board - Sun Microsystems Ultra 1 140 Service Manual

10

10.1 System Board

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10.1.1 Removing a System Board
10-2
Caution – Use an antistatic mat when working with the system board. An
antistatic mat contains the cushioning needed to protect the underside
components, to prevent board flexing, and to provide antistatic protection.
Note – Before removing a defective system board, you must remove all
DSIMMs and SBus card(s) from the defective board. Note the slots for each of
the SBus cards. DSIMMs and SBus card(s) should be replaced on the
replacement system board later.
Note – The NVRAM/TOD (Non-Volatile Random Access Memory/Time Of
Day) clock contains the system's host id and Ethernet address numbers. If you
want to use the same numbers on the replacement board, you must remove the
NVRAM/TOD from the defective system board, and install it on the
replacement system board after it is installed in the system.
1. Remove each NVRAM/TOD from the defective system board and from
the replacement system board.
See Section 10.2.1, "Removing a NVRAM/TOD," on page 10.
2. Remove all of the SBus card(s) from the defective system board.
See Section 10.3.1, "Removing an SBus Card," on page 12.
3. Remove all DSIMMs from the system board.
See Section 10.4, "DSIMM," on page 18.
4. Disconnect the SCSI cable from the system board at J2602.
See Figure 10-1.
Sun Ultra 1 Series Service Manual—November 1995