Install guide

ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
(b)
(c)
Apply sealing compound primer (MIL-
S-22473) to male threads of retainer nut.
After primer has dried, apply sealing com-
pound (MIL-S-22473, Grade C) to male
threads of retainer nut. Sealing compound
shall cover the full engaging length of one
of the mating components; assemble parts.
3-17. CDU Maintenance. CDU repair consists of re-
moval and replacement of circuit card assemblies. Fig-
ure 3-9 is an exploded view of the CDU.
a. Display Logic Circuit Card Assemblies Al and
A2 and Keybord and Control Circuit Card Assembly A3.
Remove and replace display logic circuit card assembly
Al or A2 (4 or 5, figure 3-9) or keyboard and control
circuit card assembly A3 (6) as follows:
(1) Removal.
(a) Remove 16 screws (1) and washers (2) secur-
ing control and display panel (3) to control
and display unit cover (7). Separate control
and display unit cover (7) and control and
display panel (3) to provide access to circuit
card assemblies,
(b) Using card extractor, remove display logic
circuit card assembly Al (4), A2 (5), or
keyboard and control circuit card assembly
A3 (6) as applicable.
(2) Replacement.
(a)
(b)
(c)
(d)
(e)
Insert card into guide and carefully guide it
into place. If card jams, pull it back out
with card extractor. Refer to table 3-6 for
card identification.
Just before the connectors mate, check that
card is free in its guides and its top edge is
parallel to the CDU top surface.
Seat card by applying moderate even pres-
sure at both sides. If excessive insertion
force is required or the card is not fully
seated, remove the card and inspect for bent
or broken connector pins.
Inspect gasket (8). Replace if cracked, tom,
loose, or excessively compressed.
Place control and display panel (3) against
control and display unit cover (7). Secure
control and display panel (3) to control and
display unit cover with 16 screws (1) and
washers (2) and torque to 5 inch-pounds
using procedures described in paragraph
3-11.
3-18. IMU Maintenance. Repair of the IMU consists of
removal and replacement of bolt assemblies, guide pin,
thermostatic switch, and repair of the IMU cover and
porro prism cover. Figure 3-10 is an exploded view of
the IMU.
a. Bolt Assembly. Remove and replace bolt assem-
bly (21, figure 3-10) as follows:
(1) Removal.
(a) Remove retainer nut (19) securing bolt as-
sembly (21) to lower IMU subassembly (13).
(b) Remove bolt assembly (21). Retain two
washers (20) for reassembly.
(2) Replacement.
Isopropyl alcohol is flammable and gives
off harmful vapors. Use only in well-ven-
tilated area away from open flames and
sparks. Avoid prolonged or repeated inha-
lation of vapors.
(a)
(b)
(c)
(d)
(e)
Clean bolt assembly (21) threads using iso-
propyl alcohol and clean, lint-free cloth;
wipe dry.
Place washers (20) on bolt assembly (21);
insert bolt assembly (21) through mounting
hole.
Apply sealing compound primer (MIL-
S-22473) to bolt assembly (21) threads; al-
low to dry.
Apply sealing compound (MIL-S-22473,
Grade C) to bolt assembly (21) threads,
Install retainer nut (19) securing bolt assem-
bly (21) to lower IMU subassembly (13).
Torque retainer nut 10 to 12 inch-pounds.
b. Guide Pin. Remove and replace guide pin (14,
figure follows:
(1) Removal. Unscrew guide pin (14) from lower
IMU subassembly (13).
(2) Replacement.
Isopropyl alcohol is flammable and gives
off harmful vapors. Use only in well-ven-
tilated area away from open flames and
sparks. Avoid prolonged or repeated inha-
lation of vapors.
3-33