Sun Microsystems SPARC classic X, Service Manual

Page: 148 / 198

11-26 SPARCclassic/SPARCclassic X/SPARCstation LX Service Manual • November 1993
6. Disconnect all cables attached to the main logic board.
For connector locations, refer to
FIGURE 11-12
and
FIGURE 11-13
in Section 11.4 “Main
Logic Board” on page 11-17.
a. Disconnect the 12-pin power supply cable from its mating connector by
squeezing the clip at the end of the cable and pulling straight up.
b. Disconnect the keyboard soft power-on cable from its connector next to the 12-
pin power supply connector.
c. Disconnect the LED/speaker cable from its mating connector on the main logic
board.
d. Disconnect the diskette drive data cable (if present) and the hard disk drive
data cable from their connectors at the front of the main logic board.
7. Remove the NVRAM chip.
See Section 11.5 “Nonvolatile RAM (NVRAM)” on page 11-31, for details. Place the
NVRAM chip on the antistatic mat. Save the chip for installation on the replacement
main logic board.
8. Remove the main logic board.
a. Pull the MLB (main logic board) extractor lever toward the front of the system
unit to disconnect the main logic board from the system I/O board
(see
FIGURE 11-15
).
b. Raise the speaker assembly to allow removal of the main logic board
(see
FIGURE 11-16
).
c. Grasp the board by the SBus connectors with both hands. Tilt the board
slightly to avoid the speaker assembly and lift it up and out of the system unit
(see
FIGURE 11-17
). Avoid handling any of the delicate electronic components or
touching any of the circuit board traces.
d. Place the main logic board on an antistatic mat.