Repair.

55-4920-244-14

(5) Replace defective tubes (para. 4-

(6) Use a decade resistance bridge or

36.)

other precision resistance checker to make sure

all resistors are within tolerance.

(6) Replace resistors not within toler-

ance indicated on body.

NOTE

(7) Replace any capacitors not within

Unsolder one lead of re-

tolerance or showing excessive leakage.

sistor under test to iso-

late from circuit.

(8) Repair broken wiring in cable

harness as follows:

(7) Use a suitable capacitor checker

(a) If slack in wire beyond end

to test all capacitors for leakage and capacity.

of cable permits, bare 1/4 inch of wire at break

(8) Inspect cable harness and all

and install in terminal in place of broken end.

wiring for broken wires and condition of insula-

(b) If insufficient slack is pres-

tion.

ent, splice a suitable length of same size and

(9) Inspect all wiring for shrinking

color wire at break and cover splice with 3/32-

of insulation or other signs of overheating.

or 1/8-iinch plastic tubing or an approved elec-

(10) Inspect electrolytic (polarized)

trical tape. If same color wire is not available,

capacitors for leakage of electrolyte.

use white wiring and color code insulation on

(11) Use an ohmmeter or suitable

terminal end with color(s) of original wire.

continuity checker to test transformer for open

windings, continuity between windings, or conti-

within cable harness and is readily located, re-

nuity between windings and case.

pair as in (b) above. Do not splice more than

e. Repair.

once in any conductor.

(1) Replace any of the printed cir-

(d) If wiring break is detected

cuit boards if any of the following conditions

within cable harness and not readily located, re-

exist:

place wire as outlined in (9) below.

(a) Separation of plies in board

(e) Cover any minor damage to

material.

wiring insulation by covering individual wires

(b) Cracks over 1/8 inch in

with 3-32- or 1/8-inch plastic tubing.

length, or extending into a terminal mounting.

(9) Repair wiring having burnt or

terminals or between terminals and ground.

shrunken insulation as follows:

(d) Loose, separated, or broken

(a) Trace affected wire to its

terminal lugs.

origin. Unclamp and untie cable harness along

(2) Separate all components at cold

entire length of affected wire.

soldered or corroded joints. Clean terminal and

(b) Examine other wires in cable

conductors of all corrosion and excess solder. Tin

harness for heat damage to insulation.

all surfaces to be soldered and remake joint.

damaged wiring, using same size and color wire.

CAUTION

If same color wire is not available, use white

Provide a heat sink on

wiring and color code insulation on both ends

precision resistor leads be-

with color(s) of original wire.

tween body of resistor

(d) Bundle wiring along origi-

and point being soldered

nal path of cable harness and lace in accordance

or tinned to prevent dam-

with instructions contained in TM 55-1500-323-

age from overheating

25 at 1-inch intervals.

when soldering.

(10) Replace potentiometer if erratic

(3) Replace nicked or scored compo-

action is noted as adjusting screw is turned.

nents or components with broken leads. Replace

(11) Replace electrolytic (polarized)

any component showing signs of overheating and

capacitors if swollen or signs of electrolyte leak-

determine cause.

age are noted at seams or terminals.

(4) Replace tube or relay sockets if

damaged or if carbonized paths are found. Re-

(12) Replace relay clamp if defective.

place or tighten missing or loose attaching hard-

(13) Replace transformer if condi-

ware.

tions in

above exist.

4-26