Main Logic Board - Sun Microsystems SPARC classic Service Manual

UNIT BOTTOM
System
I/O board
DSIMMs
(fully populated)
Hard drive data cable
Hard drive power cable
=
FIGURE 1-3
1.1.1

Main Logic Board

The main logic board (MLB) resides in the bottom half of the system unit. It plugs
into the system input/output (I/O) board, which provides all of the external
connectors to the system unit's back panel (see
The different SPARCclassic/SPARCclassic X/SPARCstation LX MLB layouts are in
Chapter 10 "System Board Overview.
SPARCclassic and the SPARCclassic X main logic board, while
FIGURE 10-3
Customer replaceable units (CRUs) residing on the main logic board include:
Memory modules
Video single in-line memory modules (VSIMMs) (SPARCstation LX only)
SBus cards
Nonvolatile random access memory (NVRAM)
1-4 SPARCclassic/SPARCclassic X/SPARCstation LX Service Manual • November 1993
SBus card
(system option)
SBus slots
Hard drive
Not applicable to the
SPARCclassic X terminal
System Unit Internal Components
show the SPARCstation LX main logic boards.
VSIMM module (option on SPARCstation LX only)
Main logic board
Speaker/Power LED assembly
Keyboard soft power-on cable
Main logic power cable
UNIT TOP
FIGURE 1-2
shows a simplified layout of the
FIGURE 10-1
Diskette drive data cable
Diskette drive
Power supply
).
and
FIGURE 10-2