Permanent Noise from the Cockpit Loudspeakers

TASK 23-51-00-810-851-A
Permanent Noise from the Cockpit Loudspeakers

1. Possible Causes

LOUD SPEAKER-CAPT [7WW]
LOUD SPEAKER-F/O [8WW]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-53-00-810-969-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-41-00-810-855-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-43-00-810-871-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-48-00-810-850-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-51-00-810-836-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-51-00-810-837-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-53-00-810-835-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-53-00-810-836-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-55-00-810-842-A	Permanent noise from the cockpit loudspeaker(s)
TSM TASK 34-55-00-810-843-A	Permanent noise from the cockpit loudspeaker(s)
AMM 31-53-21-000-001	Removal of the Loudspeakers
AMM 31-53-21-400-001	Installation of the Loudspeakers

3. Fault Confirmation
Subtask 23-51-00-700-051-A

A. Test
(1) Not applicable, the fault is evident.

4. Fault Isolation
Subtask 23-51-00-865-060-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	NAV/ADF/1	1RP1	H14
** ON A/C ALL
49VU	FWS/FWC1/SPLY	3WW	F01
49VU	NAV/DME/1	1SD1	G14
49VU	NAV/VOR/1	2RS1	G13
** ON A/C NOT FOR ALL
49VU	NAV/ADF/1	1RP1	F09
** ON A/C ALL
121VU	COM NAV/RADAR/1	5SQ1	K13
121VU	COM NAV/TCAS	4SG	K10
121VU	COM NAV/VOR/2	2RS2	K08
121VU	COM NAV/DME/2	1SD2	K06
121VU	EIS/GPWS/115VAC	3WZ	P07
121VU	EIS/FWC2/SPLY	2WW	Q07
** ON A/C NOT FOR ALL
121VU	COM NAV/ADF/2	1RP2	K02

Subtask 23-51-00-810-100-A

B. If the test confirms the fault:
(1) If you hear a permanent noise on one loudspeaker only:
(a) Replace the loudspeaker on which you heard a permanent noise:

LOUD SPEAKER-CAPT [7WW] or LOUD SPEAKER-F/O [8WW] AMM 31-53-21-000-001 and AMM 31-53-21-400-001.

(2) If you hear a permanent noise on both loudspeakers:

Continue the trouble shooting procedure.

Subtask 23-51-00-810-101-A ** ON A/C NOT FOR ALL

C. If the fault continues:
(1) Open the circuit breaker 4SG or 104SG (if installed).
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 4SG or 104SG (if installed).
Do this trouble shooting procedure (Ref. TSM TASK 34-43-00-810-871).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 4SG or 104SG (if installed).
Continue the trouble shooting procedure.

Subtask 23-51-00-810-101-B ** ON A/C NOT FOR ALL

C. If the fault continues:
(1) Open the circuit breaker 2004SG (if installed).
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 2004SG (if installed).
Do this trouble shooting procedure (Ref. TSM TASK 34-72-00-810-912).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 2004SG (if installed).
Continue the trouble shooting procedure.

Subtask 23-51-00-810-102-A

D. If the fault continues:
(1) Open the circuit breaker 2WW or 3WW.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 2WW or 3WW.
Do this trouble shooting procedure (Ref. TSM TASK 31-53-00-810-969).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 2WW or 3WW.
Continue the trouble shooting procedure.

Subtask 23-51-00-810-103-A ** ON A/C NOT FOR ALL

E. If the fault continues:
(1) Open the circuit breaker 3WZ or 104SG.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 3WZ or 104SG.
Do this trouble shooting procedure (Ref. TSM TASK 34-48-00-810-850).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 3WZ.
Continue the trouble shooting procedure.

Subtask 23-51-00-810-104-A

F. If the fault continues:
(1) Open the circuit breaker 5SQ1 or 5SQ2.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 5SQ1 or 5SQ2.
Do this trouble shooting procedure (Ref. TSM TASK 34-41-00-810-855).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 5SQ1 or 5SQ2.
Continue the trouble shooting procedure.

Subtask 23-51-00-810-105-A

G. If the fault continues:
(1) Open the circuit breaker 1RP1 or 1RP2.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 1RP1 or 1RP2.
Do this trouble shooting procedure (Ref. TSM TASK 34-53-00-810-835) or (Ref. TSM TASK 34-53-00-810-836).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 1RP1 or 1RP2.
Continue the trouble shooting procedure.

Subtask 23-51-00-810-106-A

H. If the fault continues:
(1) Open the circuit breaker 2RS1 or 2RS2.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 2RS1 or 2RS2.
Do this trouble shooting procedure (Ref. TSM TASK 34-55-00-810-842) or (Ref. TSM TASK 34-55-00-810-843).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 2RS1 or 2RS2.
Continue the trouble shooting procedure.

Subtask 23-51-00-810-107-A

I. If the fault continues:
(1) Open the circuit breaker 1SD1 or 1SD2.
(a) If the permanent noise does not occur on both loudspeakers:

Close the circuit breaker 1SD1 or 1SD2.
Do this trouble shooting procedure (Ref. TSM TASK 34-51-00-810-836) or (Ref. TSM TASK 34-51-00-810-837).

(b) If the permanent noise occurs on both loudpseakers:

Close the circuit breaker 1SD1 or 1SD2.
Continue the trouble shooting procedure.

5. Close-up
Subtask 23-51-00-942-050-A

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.

[Rev.8 from Aug 2018] 2026.04.04 04:25:47 UTC