Operational Test of the Audio Management Unit (AMU)

TASK 23-51-00-710-001-A
Operational Test of the Audio Management Unit (AMU)

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

WARNING: OBEY THE RADIO REGULATIONS AND MAKE SURE THAT THE FREQUENCY IS AVAILABLE BEFORE YOU TRANSMIT.

ZONE: 210

1. Reason for the Job
To do a check of the operation of the audio management system.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	BOOMSET 600 OHMS
No specific	1	HEADSET 600 OHMS
No specific	1	MICROPHONE 150 OHMS - HAND

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)

3. Job Set-up
Subtask 23-51-00-860-050-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) On all the ACPs, make sure that:

The RAD/INT selector switch is in the center position
All transmission pushbutton switches are fully out.
All reception pushbutton switches are pushed (no reception).

(3) On the maintenance panel 50VU, make sure that the SVCE INT OVRD pushbutton switch is not pushed.
(4) On the overhead control and indicating panel 48VU, make sure that the AUDIO SWITCHING selector switch is in the NORM position.
(5) Set the LOUD SPEAKER potentiometers on the panels 301VU and 500VU to the middle position.
(6) Boomset connection.

At each crew station, connect a BOOMSET 600 OHMS to the jack panel.
On the panel 108VU, connect a boomset.

(7) Microphone and headset connection:

At each crew station, connect a MICROPHONE 150 OHMS - HAND to the HAND MIC connection.
Connect a HEADSET 600 OHMS to the HEADSET connector.

Subtask 23-51-00-865-050-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/AUDIO/ACP/F/O	5RN	G07
** ON A/C NOT FOR ALL
49VU	COM/AUDIO/FLT/INTPH	9RN	G08
49VU	COM/AUDIO/ACP/CAPT	4RN	G06
** ON A/C ALL
49VU	CAPT/LOUD/SPKR	5WW	F10
49VU	COM/RMP/1	2RG1	G10
49VU	COM/VHF/1	2RC1	G09
** ON A/C NOT FOR ALL
49VU	COM/ACP F/O/BITE/ INT 2 AUDIO/3&5 OCCPNT	5RN	G07
** ON A/C NOT FOR ALL
49VU	COM/INT/1+2	9RN	G08
49VU	COM/ACP CAPT/SELCAL/INT 1 AUDIO/AVNCS	4RN	G06
** ON A/C ALL
121VU	COM NAV/SELCAL	8RN	M04
121VU	COM NAV/ACP/THIRD/OCCPNT	6RN	M02
121VU	EIS/F/O/LOUD/SPKR	4WW	P08
** ON A/C NOT FOR ALL
121VU	COM NAV/ACP/FOURTH/OCCPNT	20RN	M01

4. Procedure
Subtask 23-51-00-710-051-A

A. Do the operational test:

NOTE: This procedure is applicable for all the crew stations.

ACTION	RESULT
1.At each crew station, on the ACP:
Push the INT transmission pushbutton switch.	The green bars on the INT transmission pushbutton switch come on.
Push and release the INT reception pushbutton switch and then turn it to the middle position.	The reception pushbutton switch moves fully out and comes on.
2.On the ACP of the station where you do the maintenance:
Set the INT/RAD selector switch to RAD and hold it in this position (You can do this operation on the PTT switch of the side stick controller at the CAPT or F/O station).
Speak in the boomset microphone.	At the Captain's and First Officer's stations: Make sure that the loudspeakers operate.
	At each crew station and at the ground mechanic station: Make sure that the reception in the boomset is correct.
Smoothly turn the INT reception pushbutton switch clockwise.	At the station where you do the maintenance: The reception you can hear must change smoothly without interference in the boomset. NOTE: During the test at the CAPT and F/O stations, the volume in the related loudspeakers also changes smoothly without interference.
Turn the INT pushbutton switch to the middle position.
3.At the Captain's and First Officier's stations:
Smoothly turn the loudspeaker potentiometer clockwise.	The reception you can hear must change smoothly without interference in the loudspeaker.
4.On the ACP of the station where you do the maintenance:
Release the INT/RAD selector switch (or the PTT switch on the side stick controller at the CAPT or F/O station)	The INT/RAD selector switch goes back to the middle position.
5.At each crew station, on the ACP:
Set the INT/RAD selector switch to INT.
6.At the ground mechanic station:	At each crew station :
Speak in the boomset microphone.	Make sure that the reception in the boomset is correct.
7.At each crew station, on the ACP:
Set the INT/RAD selector switch to the middle position.
Push the INT transmission pushbutton switch.	The green bars on the INT transmission pushbutton switch go off.
8.On the RMP1:
Set the ON/OFF selector switch to ON.	The RMP shows the last frequencies and the last function used.
Push the VHF1 pushbutton switch.	The green LED on this pushbutton switch comes on.
In the STBY/CRS display window, with the dual selector knob, set the frequency of a station that transmits.
Start this frequency. To do this, push the transfer pushbutton switch (double arrow) between the two display windows.	The frequency set comes into view in the left ACTIVE display window.

9.On the ACP of the station on which you do the maintenance:
Push the VHF1 transmission pushbutton switch.	The green bars on the VHF1 transmission pushbutton switch come on.
Push and release the VHF1 reception pushbutton switch.	The reception pushbutton switch moves fully out and comes on.
Set the INT/RAD selector switch to INT and speak in the boomset microphone.	At the station where you do the maintenance: Make sure that you receive the VHF1 station and the interphone at the same time.
	At the other crew station: Make sure that you can hear the communications only from the station where you do the maintenance.
Set the INT/RAD selector switch to the center position.
Push the VHF1 transmission pushbutton switch.	The green bars on the VHF1 transmission pushbutton switch go off.
Push the VHF1 reception pushbutton switch.	This pushbutton switch moves in (to the initial position) and the annunciator light goes off.
10.At each crew station, on the ACP:
Push the INT reception pushbutton switch.	This pushbutton switch moves in (to the initial position) and the annunciator light goes off.
11.On the RMP1:
Set the ON/OFF selector switch to OFF.

Subtask 23-51-00-710-053-A

B. Do the operational test:

NOTE: This procedure is applicable for all the crew stations.

ACTION	RESULT
1.At each crew station, on the ACP:
Push the INT transmission pushbutton switch.	The green bars on the INT transmission pushbutton switch come on.
Push and release the INT reception pushbutton switch.	The reception pushbutton switch moves fully out and comes on.
2.At the station where you do the maintenance:	At the Captain's and First Officer's stations:
Push the PTT switch of the hand microphone and speak in the microphone.	Make sure that the loudspeakers operate.
	At each crew station: Make sure that the reception in the headset is correct.
	At the ground mechanic's station: Make sure that the reception in the boomset is correct.
3.On the ACP of the station where you do the maintenance:
Smoothly turn the INT reception pushbutton switch clockwise.	The reception you can hear must change smoothly without interference in the headset. NOTE: During the test at the CAPT and F/O stations, the volume in the related loudspeakers also changes smoothly without interference.
4.At the crew station under maintenance:
Release the PTT switch of the hand microphone.

5. Close-up
Subtask 23-51-00-860-051-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) At each crew station, on the ACP, push the INT transmission and reception pushbutton switches.
(2) Disconnect the microphone and the headset for all the crew stations.
(3) Disconnect the boomset on the panel 108VU.
(4) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.03.31 23:15:32 UTC