Section IV TROUBLESHOOTING

TM 11-5820-670-12

Section IV TROUBLESHOOTING

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Page

Subject

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 3-8

Troubleshooting Procedures . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9

3-8. GENERAL.

Troubleshooting at the organizational maintenance level is confined to localizing trouble to a defective

major unit or items such as knobs, improper mating of connectors, or defective cables or connectors.

When performing organizational preventive maintenance checks and services (PMCS), Section Ill and

the operational check (para 3-12) direct references to the troubleshooting chart are made. Refer-

ences from the operation check are directed to specific numbered procedures. The chart does not list

all problems that can exist. If a problem is not listed and or the steps given do not solve it, report the

problem to the next higher level of maintenance. When working on any problem, be sure to report work

on applicable forms shown in DA Pam 738-750.

TROUBLESHOOTING PROCEDURES.

3-9.

The troubleshooting chart presented lists the most probable malfunctions that may be found while

performing organizational PMCS and/or operational check. The appropriate test(s) and/or

inspection(s) are given with actions to correct the malfunction. After correction, an operational

check (para 3-12) must be performed to ensure correct operation. If check fails, refer to next higher

level of maintenance.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. Control unit panel lamps do not light when aircraft primary power is on.

Step 1.

Check aircraft panel light control.

Adjust brilliancy of lamp until control unit illuminates.

Repeat aircraft primary power-on sequence. If control unit panel lamp does not

Step 2.

light, lamp assembly in control unit is defective.

Remove and replace control unit (para 3-11).

2. Aircraft 27.5-volt circuit breaker opens when radio set is turned on.

Turn radio set off, reset circuit breaker, and turn radio set back on. If circuit

Step 1.

breaker trips open again, primary power is shorted in receiver-transmitter or

control unit.

Remove and replace receiver-transmitter (para 3-11).

After replacing receiver-transmitter, reset circuit breaker and turn radio set on.

Step 2.

If circuit breaker opens, control unit is shorting primary power.

Remove and replace control unit (para 3-11).

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