TM 11-5895-856-34-1/ E E640-CA-MMI-010/E 154 CPU/TO 31W2-2T-122-1
securing ore stack to door B (fig. 3-10) support structure
side of card cage/core stack to frame assembly. First
and remove core stack.
person hold card cage/core assembly to assure it will not
b. Replacement.
fall; second person remove remaining supporting cross-
slotted screws.
WARNING
The MCMU core stack weight is
WARNING
approximately 53 pounds. To avoid
Card cage/core assembly will drop
injury to personnel, two persons are
when last two screws are removed.
required to replace MCMU.
(9) Both persons lift out card cage/core stack
assembly being very careful not to damage wiring and
(1) Insert core stack and tighten core stack
pins.
captive fasteners securing it to door B support structure
NOTE
To remove core stack from card cage
(2) Tighten connectors to core stack.
perform the following steps:
(3) Grasp handle on door A main door and
WARNING
pull to closed position.
The MCMU card cage/core stack
(4) Tighten door A main door captive
assembly weight is approximately
fasteners securing door A to cabinet assembly.
100 pounds.
To avoid injury to
(5) At the circuit breaker panel DC group, set
personnel, two persons are required
PROCESSOR 1 or 2 (MCMU 1 or 2) to ON.
to place assembly on soft surface.
3-17. MCMU Card Cage/Core Stacks A1A15 (MCMU
(10) Place the card cage/core stack assembly
1B) and A1A16 (MCMU 2B) Removal and
AlA15 or AlA16, card cage face down on a soft surface.
Replacement
(11) Disconnect connectors (P1 through P22)
a. Removal
from core stack A1A15 or A1A16.
(1) At the circuit breaker panel DC group, set
(12) Loosen core stack captive fasteners
PROCESSOR 1 or 2 (MCMU 1B or MCMU 2B) to OFF.
securing core stack to mounting brackets and remove
(2) Loosen frame assembly D (fig. 3-11)
core stack.
captive fasteners securing frame assembly to cabinet
b. Replacement.
assembly.
(1) Place core stack on mounting brackets
(3) Grasp the two handles on frame assembly
and tighten captive fasteners to secure core stack to
D and pull frame assembly out to opening position. This
card cage.
provides access to front of the card cages.
(2) Insert and tighten connectors (P1 through
(4) Using card extractor, disconnect all ribbon
P22) to core stack.
cables from card cage/core stack assembly being
WARNING
removed.
The MCMU card cage/core stack
(5) Disconnect power cable connectors from
assembly weight is approximately
card cage/core stack assembly being removed.
100 pounds.
To avoid injury to
WARNING
personnel, two persons are required
The MCMU card cage/core stack
to install card cage/core stack
assembly weight is approximately
assembly into frame assembly.
100 pounds. Replacement of card
cage/core assembly is a two-person
(3) Insert card cage/core stack assembly
operation. One must support the
A1A15 or A1A16 into frame assembly D. First person
assembly, while the other removes
hold the card cage/core stack assembly; second person
attaching hardware. If the assembly
replace two cross-slotted screws (en opposite upper
is allowed to fall when hardware is
corners which secure left and right side of card
removed, core stack or card cage
cage/core stack to frame assembly.
damage may result.
(4) Install and tighten ten hex screws, 11 hex
recessed screws, and cross-slotted screws.
(6) Remove ten hex screws which secure top
(5) Install ribbon cables connectors to card
of card cage/core stack assembly to frame assembly.
cage.
All cables are marked to indicate mating
(7) Remove eleven hex-recessed screws
connectors.
which secure bottom of card cage/core stack A1A15
(6) Install power cable connectors to card
assembly to frame assembly.
cage.
(8) Remove all but two cross-slotted screws
(7) Grasp two handles on frame assembly D
(on opposite upper corners) which secure left and right
and
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