TROUBLESHOOTING PROCEDURES-continued

TM 11-5820-670-12

TROUBLESHOOTING PROCEDURES. (CONT)

3-9.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

If grounding and aircraft intercommunications system is checked and found

Step 3.

operating, receiver-transmitter is defective.

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

10. Squelch does not operate properly.

Step 1.

Check SQ ADJ on receiver-transmitter for proper setting,

Adjust SQ ADJ (para 3-4).

Step 2.

If adjusting SQ ADJ on receiver-transmitter does not correct malfunction,

receiver-transmitter or control unit is defective.

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

Step 3.

If squelch does not operate after replacement of receiver-transmitter, control

unit is defective.

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

11. Radio set will receive but will not transmit.

Check settings on control unit for correct transmit/receive operation. If all settings are

correct, receiver-transmitter is defective.

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

12. Radio set will transmit but will not receive.

Step 1.

If signal can be heard with control unit SQUELCH control set at DIS but not at

CARR, check squelch adjustments (SQ ADJ) on receiver-transmitter.

Adjust SQ ADJ (para 3-4).

Step 2.

Check aircraft intercommunications system for discrepancies.

Refer to applicable aircraft electronic maintenance manual for checks

and corrective action.

Step 3.

Reset all controls on control unit for transmit/receive operation. If radio set still

does not receive, receiver-transmitter is defective.

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

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