Section II. GENERAL SUPPORT REPAIR PROCEDURES

TM 11-6760-238-34

Section II. GENERAL SUPPORT REPAIR PROCEDURES

(steps (1) through (3) above).

4-5. General

WARNING

When making repairs or adjustments, be

Before beginning any work with these

extremely careful of the ac line voltage.

chemicals, be sure to check with the

Always disconnect the power source

local Safety Office or Preventive

from the equipment when making

Medicine Activity. They can inform you

repairs.

of any special precautions (handling,

4-6. General Support Disassembly/Assembly

storage, accidental contact with, etc.) to

take to avoid any health hazards.

Procedures (FO-6)

NOTE

Most of the assemblies, subassemblies, and parts in the

General support maintenance includes

shutter test set can be reached easily and replace

all repair operations covered in lower

without the use of special tools When replacing part the

level manuals and lower level portions of

general techniques and precautions in paragraph 3-11

this manual as well as those covered in

and 3-12 apply.

this chapter.

a. Epoxy Coating. After any maintenance has

a. Removal of Test Panel Assembly. Refer to

been performed that requires removal of the surface

paragraph 3-8a for removal of test panel assembly.

coating on test board and components assemblies, the

Removal of SHUTTER MECHANISM

exposed areas must be recoated for fungus and

Connector J3.

moisture protection using the following procedure.

NOTE

WARNING

The following instructions will apply for

Xylol is toxic and flammable, use it only

the removal and replacement of RELAY

in small quantities m a well ventilated

ASSY

connector

J1,

SHUTTER

area. Do not breathe vapors or allow

connector J5, CONTROL PANEL

liquid to contact the skin. Do not use in

connector J6 and BRIDGE ASSY

the presence of open flame or sparks.

connector J7.

(1) Part A (Resin). Measure 100 parts by

(1) Unsolder and tag all wires attached to

weight of Araldite 571 CX (manufactured by Ciba Co.,

SHUTTER MECHANISM connector J3( ).

Fair Lawn, NJ) with 29 parts by weight of Beetle 216-8

(2)

Remove four screws (1), four

(manufactured by American Cyanamid Co.) and stir well.

flatwashers (2), four nuts (3), and remove SHUTTER

Mix 27 parts by weight of Diacetone Alcohol (Federal

MECHANISM connector J3 (4) from rear of test panel

Specification O-D-306) and stir well. Store in separate

(10).

container.

c. Replacement of SHUTTER MECHANISM Con-

(2) Parts B (Hardener). Measure 100 parts

nector J3.

by weight of Araldite 820 (manufactured by Ciba Co.,

(1)

Position SHUTTER MECHANISM

Fair Lawn, NJ) with 37.5 parts by weight of Xylol (Federal

connector J3 (4) in test panel (10) and secure with

Specification TT-X-916) and stir well. Mix 20 parts by

hardware removed in step b(2) above.

weight of Butyl Alcohol (Federal Specification TT-B-846)

(2) Replace and solder all wires removed in

and stir well Store m separate contamer.

step b(1) above.

b. To Prepare Epoxy for Immediate Use. To

d. Removal of POWER Connector J2.

prepare the epoxy for immediate use, mix two parts "A"

(1) Remove two top screws (20), two

(Resin) with one part "B" (hardener) in a quantity that can

flatwashers (2), two nuts (3), and remove component

be used in eight hours. Mix thoroughly. Brush the

assembly (19) away from test panel (10).

mixture onto the areas to be coated, making sure to

(2) Unsolder and tag all wires attached to

avoid areas that require mechanical movement such as

POWER connector J2 (5).

control adjustments and wafer switch contacts.

(3) Remove bottom two screws (1),

(1) The epoxy mixture will dry to the touch in

flatwashers (2), nuts (3), and remove POWER connector

approximately 1 hour when applied in a film of 0.005 to

J5 (5) from test panel (10).

0.010 inch thickness. Total curing time requires 24

e. Replacement of POWER Connector J2.

hours at room temperature.

Curing time can be

(1) Position POWER connector J2 (5) in

shortened by heating in a circulating oven at 1500 F for

test panel (10) and secure with hardware removed in

hours.

step d(3) above.

(2) If necessary to spray Epoxy coating, thin

(2) Replace and solder all wires removed in

wit Xylol (Federal Specification TT-X-916).

step d(2) above.

(3) Mask over terminals on both sides of

(3) Position component assembly (19) on

printed circuit boards before applying Epoxy coating

POWER

4-3