Main Logic Board Replacement - DEC DECstation 316+ Service Manual

3–28 FRU Replacement

3.2.15 Main Logic Board Replacement

Replace the main logic board as follows:
NOTE
DECstations 316+/325
C main logic board (Figure 3–16) Later models may be
equipped with a Rev D main logic board).
DECstations 320 /425
+
(Figure 3–17). Jumper settings on both Rev C and D main
logic boards must be configured specifically for each
DECstation model. See Section 3.3 for jumper locations
and configuration information.
1. Remove the system cover (Section 3.2.4).
2. Remove all option boards. (Section 3.2.12).
3. Remove the power supply from the system (Section 3.2.13).
4. Disconnect all cables connected to the main logic board and
note their location and routing.
5. Remove the mounting tray for floppy drive B by removing the
two mounting screws that secure the tray to the front of the
system chassis.
6. Remove the card guide by removing the two mounting screws
that secure it to the front of the system chassis (one of the
screws will have been removed already when the CPU board
was removed).
7. Remove the main logic board by performing the following
steps:
a. Remove the two screws that secure the keyboard/serial
connector to the back of the chassis.
b. Remove the 11 screws that secure the main logic board to
the chassis.
c. Remove the main logic board as shown in Figure 3–14.
8. Set the jumpers and switches on the replacement board to
match those on the old board
/333 were introduced with a Rev
C C
have a Rev D main logic board
C