Installing The New Main Logic Board - Sun Microsystems SPARC classic Service Manual

11.4.4

Installing the New Main Logic Board

This section explains how to install a replacement main logic board in the system
unit.
To install the main logic board:
1. Remove the defective main logic board as described in the previous section.
2. Install the NVRAM on the replacement main logic board.
Take the NVRAM chip you removed from the old main logic board and install it on
the new main logic board. See Section 11.5 "Nonvolatile RAM (NVRAM)" on
page 11-31, for details.
3. Install the DSIMMs.
Remove DSIMMs taken from the old main logic board and install them in the
corresponding DSIMM slots of the new logic board. See Section 11.3.3 "Replacing a
DSIMM" on page 11-15, for installation details.
4. Install the optional VSIMM (if applicable).
See Section 11.2.2 "Replacing the VSIMM" on page 11-9, for installation details.
5. Install the new main logic board.
a. Grasp the board by the SBus connectors with both hands and guide the main
logic board extractor lever through the rectangular cutout in the main logic
board (see
components or touching any of the circuit board traces.
b. Tilt the board to avoid the speaker assembly and lower it onto the floor of the
system unit.
c. Align the board's edge connector with its mating connector on the system I/O
board.
d. Push the main logic board extractor lever toward the rear of the system unit to
plug the main logic board into the system I/O board (see
e. Lower the speaker assembly back to its original position.
). Avoid handling any of the delicate electronic
FIGURE 11-17
Chapter 11 Main Logic Board and Component Replacement
).
FIGURE 11-18
11-29