TROUBLESHOOTING PROCEDURES-continued

TM 11-5820-670-12

3-9. TROUBLESHOOTING PROCEDURES. (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. Blower fan at rear of receiver-transmitter does not operate when radio set is turned on and

receiver-transmitter is keyed to transmit.

Turn radio set off, check/reset circuit breaker, and turn radio set back on and key

transmitter. If blower fan does not operate, blower motor is defective.

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

4. Receiver-transmitter TEST METER reading is not within tolerances as specified in operational

Turn radio set on, rotate TEST SWITCH to six positions, and determine out of tolerance

readings. If readings are not as specified, receiver-transmitter is defective.

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

5. Frequency selector switches do not work properly.

Manually turn frequency selector switches on control unit, checking for smooth operation.

If switches do not work smoothly and do not properly set frequency, control unit is defective

or frequency selector switch knobs are loose.

Check knobs for security of attachment. Tighten or replace knobs as

necessary. If necessary, remove and replace control unit.

6. With frequency selector switches on control unit working properly, radio set does not tune to

desired frequency.

Step 1.

Set frequency selector switches to desired frequency and check that desired

frequency has been selected. If frequency set is not achieved, receiver-

transmitter or control unit is defective.

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

Step 2.

After replacing receiver-transmitter, check frequency selected with frequency

obtained. If frequencies do not agree, control unit is defective.

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

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