Section V. PLUGS AND JACK ASSEMBLIES

TM 750-245-4

Section V. PLUGS AND JACK ASSEMBLIES

3-17. General

c. Bent and broken keys.

Plugs and jack assemblies are the beginning and end of

d. Moisture, corrosion, or any other contamination

electrical and electronic chassis. Proper input and

which would affect equipment operation.

output signals or voltages are of the utmost importance

e. Potting to insure a firm smooth texture is

in equipment operation.

evidence of moisture.

f. Broken or defective attaching hardware securing

3-18. Inspection Criteria

plugs and jacks to chassis.

The inspector should inspect all plugs and jacks for the

g. Proper identification, stenciling, labeling, etc., as

following:

required.

a. Bent, Broken, or misalinement of pins and

contacts.

b. Warped outer shells.

Section VI. SERVO MECHANISMS

3-19. General

b. Painted Surfaces.

A servo mechanism is a power driven mechanism that

(1) Smooth

supplements a primary control. It tends to position an

(2) Without scratches

object in accordance with the command given by an

(3) Chipped surfaces

arbitrarily varying position indicator capable of supplying

c. Gear Teeth. Coated lightly with grease.

only a small amount of power.

Its operation is

d. Gear Train.

dependent upon the difference between the actual

position of the object and the desired position.

(1) Binding of the gears

(2) Excessive play

3-20. In-Process Inspection (Visual)

e. Gear Stops and Dials. For correct alinement.

Visually inspect the servo for obvious damage and

f. Spur Gears. To insure that all mating spur

defects such as missing parts, loose wiring, broken

gears are alined.

connectors, broken, chipped, or burned gear teeth, and

g. Loose wiring, bad solder joints, damaged parts.

corrosion on machined surfaces.

h. Variable Resistor. Insure that resistor is filled

with oil. when required.

3-21. Final Inspection

a. Machined Surfaces.

3-22. Identification

(1) Smooth

Insure that all markings and stampings are legible.

(2) Unmarked

Touch up and restore all markings and stampings.

Section VII. BATTERIES

3-23. General

3-24. Electrolyte

The types of batteries presently in the Army inventory

The surface of the liquid should be up to indicated level.

are lead acid storage, nickel cadmium storage, dry and

Add only distilled water and do not overfill. Filler caps

thermal. The lead acid battery has an electrolyte of

should be replaced.

sulfuric acid whose specific gravity varies with the

amount of charge in the battery. The nickel cadmium

3-25. Terminals

type has an electrolyte of sodium hydroxide whose

Terminals should be free of corrosion. Storage battery

specific gravity does not vary. Dry batteries and thermal

terminals may be cleaned with an alkaline solution or

batteries are both sealed and require no maintenance

water. Corroded terminals of dry and thermal batteries

other than cleaning. Repair is authorized only on nickel

may indicate leakage. Check for broken cases.

cadmium batteries.

Inspection will cover general

condition and serviceability.

3-26. Shelf Life

The permissible shelf life of dry and thermal batteries

should be indicated. Check for expiration.

3-18