Section III. CORRECTIVE MAINTENANCE

TM 11-5821-285-12-1

Table5-1. Troubleshooting Chart-Continued

Item No.

Malfunction

Probable Cause

Corrective Action

Poor or no modulation of a radio

Defective resistor in audio pad.

Make

following resistance measurements:

transmitter from all operator

R7, R1I and R31-must read 270 ohms

stations.

10%: RS, R16, and R32-must read

100 ohms 10%. If above readings are

not obtained, request higher level

maintenance to replace defective

resistor.

Poor or no modulation of a radio

Defective resistor audio pad. Measure

following resistors: R1 through

transmitter from only one

R6, R9 through R14, and R25 through

operator station.

R30. A reading of 100 ohms 10%

must be obtained. If reading above is

not obtained, request higher level

maintenance to replace defective

resistor.

ANIARC-131 radio operates on a.

FM control head defective.

Replace FM control head (para 5-8).

some frequencies, but not on b.

Receiver-transmitter defective.

Replace defective receiver-transmitter

others.

(para 5-9).

Reception and transmission

Receiver-transmitter defective.

Replace receiver-transmitter (para

weak.

5-9), .

Antenna or antenna rf interconnection.

Request higher level maintenance

cabling defective.

check of antenna and associated rf

cabling.

Section III. CORRECTIVE MAINTENANCE

b. Replacement.

5-5. General

WARNING

(1) Connect the cable from the console to the

Verify that all power is removed from a unit prior to

connector on the rear of the ICS box.

removing or replacing parts.

(2) Rotate the two screw-type fasteners on the

a. When replacing parts, observe the following

connector one-quarter turn clockwise.

general precautions and techniques. Before a part is

(3) Reinstall the ICS box in its mounting in the

removed, note the cable connection to that part and

console.

identify each cable to be removed.

(4) Rotate the four Dzus fasteners one-quarter

b. Where damaged or defective parts must be

turn clockwise.

replaced, use only replacement parts known to be

operable. The new part must be placed in the same

6-6. Reemoalaand ReRlaclemementCof tCo, tIroerIcommor icatio

57 R movv l and pep ac nt of on roln ntl ndict un

mounting position as the one it replaces.

a. Removal

C-8151ARC (KY-28 Control

(1) Rotate the four Dzus fasteners one-quarter

a. Removal.

turn counterclockwise (eight Dzus fasteners on C-161

(1) Rotate the four Dzus fasteners one-quarter

1D1A1C).

(2) Pull the KY-28 control head from its

(2) Pull the ICS box from its mounting in the

mounting in the console as far as it will go.

console as far as the cable permits.

(3) Remove the electrical harness from the

(3) Rotate the two screw-type fasteners on the

connectors located on the KY-28 control head.

rear connector one-quarter turn counterclockwise.

b. Replacement.

(4) Disconnect the connector by pulling on it and

(1) Connect the electrical harness from the

rocking it gently.

console to the connectors located on the rear of the KY-

28 control head.

(2) Reinstall the KY-28 control head in its

mounting in the console.

(3) Rotate the four Dzus fasteners one-quarter

turn clockwise.

5-3