TM 55-4920-428-13
4 - 2 0 . C l e a n i n g
.
a. Remove dust and dirt from the interior of the test set. Use a stiff bristle brush and cleaning cloth
CCC-C-46.
Dry cleaning solvent is combustible and toxic. It can irritate skin and
cause burns. Use only with adequate ventilation, away from open
flame. In case of contact, immediately flush skin or eyes with water for
at least 15 minutes. Get medical attention for eyes.
b. For stubborn stains on the chassis, use cleaning cloth CCC-C-46 (Item 2, table 4-2) moist with dry
cleaning solvent P-D-680 (Item 1, table 4-2).
Contact cleaner is toxic. It can irritate skin and cause burns. Avoid
inhaling. Use only with adequate ventilation. Avoid contact with skin,
eyes, or clothing. In case of contact, immediately flush skin or eyes
with water for at least 15 minutes. Get medical attention for eyes.
c. Clean all rotary switches and controls. Use contact cleaner MIL-C-83360 (Item 4, table 4-2).
4 - 2 1
.
Replacement of Circuit Board PCA1 or PCA2. (CRC)
Do not handle or store circuit cards, except in a static-free environ-
ment, using static free materials. Microcircuits can be damaged by
static.
a. Remove the panel. (Ref para 4- 17.)
b (See fig. 6-3.) Remove two screws (72) securing the circuit board receptacle (74) to the two
brackets.
c. Remove three screws (75), nuts (79), washers (’9), and spacers (76) securing the circuit board
(78) to the chassis.
d. Pull the circuit board from the receptacle.
e. Insert the replacement circuit board, component side up, into the circuit board receptacle.
f. Install three screws and spacers.
g. Position the circuit board on the three screws. Secure the circuit board with three washers and
nuts.
h.
i.
j.
k.
Install two screws through the two brackets into the circuit board receptacle.
Perform the power supply and DVM tests. (Ref para 4-40.)
Install the panel. (Ref para 4-41.)
Perform the final test. (Ref para 4-42.)
4-4
