Digital Equipment DECstation 212LP, Service Manual

Page: 69 / 91

3–26 FRU Replacement
3.2.13 Main Logic Board Replacement
Replace the main logic board as follows:
1. Remove the cover (Section 3.2.4) and open the system unit
(Section 3.2.5).
2. Remove all option boards and their cables, if any,
(Section 3.2.6).
3. Remove the system unit chassis support and bus adapter
board (Section 3.2.7).
4. Remove all the SIMMs installed on the main logic board
(Section 3.2.11).
5. Remove the math coprocessor if one is installed
(Section 3.2.12).
6. Remove the power supply, power on LED, floppy/ hard/ tape
drive interface, and IDE interface cables attached to the main
logic board (Figure 3–14 and Figure 3–15).
NOTE
When removing the cables note their location and
routing.
7. Remove six 3/16-inch hex standoffs that secure the serial,
parallel, and monitor connectors to the system unit
(Figure 3–14 and Figure 3–15).
NOTE
The connectors are soldered to the main logic board.
Each connector (and main logic board) is secured to the
system unit by the six standoffs.
8. Remove the six screws securing the main logic board to the
system unit (Figure 3–14 and Figure 3–15).
9. Remove the main logic board (Figure 3–14 and Figure 3–15).
10. Set all switches and jumpers on the new main logic board to
the same positions as those set on the old main logic board.
11. Install all options (if any) that were removed from the old
main logic board onto the new main logic board.