Operational Test of the Multipurpose Control & Display Unit (MCDU)

TASK 22-70-00-710-001-A
Operational Test of the Multipurpose Control & Display Unit (MCDU)

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.

ZONE: 210

1. Reason for the Job
To make sure that the MCDU operates correctly.
2. Job Set-up Information
A. Work Zones and Access Panels

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

B. 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 22-70-00-860-054-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 22-70-00-865-052-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AUTO FLT/FMGC/1	10CA1	B02
49VU	AUTO FLT/MCDU/1	11CA1	B01
** ON A/C NOT FOR ALL
49VU	AUTO FLT/FMGC/1	10CA1	H08
49VU	AUTO FLT/MCDU/1	11CA1	H07
** ON A/C ALL
121VU	AUTO FLT/FMGC/2	10CA2	M17
121VU	AUTO FLT/MCDU/2	11CA2	N20

4. Procedure
Subtask 22-70-00-710-051-B ** ON A/C NOT FOR ALL

A. Operational Test of the MCDU

NOTE: This test is for system 1. The indications between parentheses are for system 2.

NOTE: The RDY top annunciator-light is ON when the MCDU is OFF.

NOTE: The RDY top annunciator-light is OFF when the MCDU is ON.

ACTION	RESULT
1.On the center pedestal, on MCDU1(2):	If the MCDU is OFF, the RDY top annunciator-light is on.
Push the BRT key to set the screen on and make it brighter.	The screen becomes brighter.
Push the DIM key to decrease the brightness of the screen.	The screen becomes less bright.
Make sure that the "MCDU MENU" page is shown (if not, push the MCDU MENU mode key).
Hold the DIM key.	The "MCDU SWITCHING OFF (RELEASE DIM KEY)" indication is shown on the screen.
Release the DIM key. Push the BRT key to set the screen on and adjust its brightness.
2.On overhead panel 25VU, set the ANN LT control switch to TEST.	On the center pedestal, on MCDU1(2), the "MCDU MENU" page comes into view. The FM and FAIL side annunciators come on. The FM1, IND, RDY and FM2 and other top annunciators come on.
3.Set the ANN LT control switch to BRT.	The annunciator lights go off.
4.On the center pedestal, on MCDU1(2):
Push the line select key adjacent to the "FMGC" indication.	The "A/C STATUS" page comes into view.

Subtask 22-70-00-710-051-C ** ON A/C NOT FOR ALL

A. Operational Test of the MCDU

NOTE: This test is for system 1. The indications between parentheses are for system 2.

NOTE: The RDY top annunciator-light is ON when the MCDU is OFF.

NOTE: The RDY top annunciator-light is OFF when the MCDU is ON.

ACTION	RESULT
1.On the center pedestal, on MCDU1(2):	If the MCDU is OFF, the RDY top annunciator-light is on.
Push the BRT key to set the screen on and make it brighter.	The screen becomes brighter.
Push the DIM key to decrease the brightness of the screen.	The brightness of the screen decreases.
Make sure that the "MCDU MENU" page is shown (if not, push the MCDU MENU mode key).
2.On overhead panel 25VU, set the ANN LT control switch to TEST.	On the center pedestal, on MCDU1(2), the "MCDU MENU" page comes into view. The FM and FAIL side annunciators come on. The FM1, IND, RDY and FM2 and other top annunciators come on.
3.Set the ANN LT control switch to BRT.	The annunciator lights go off.
4.On the center pedestal, on MCDU1(2):
Push the line select key adjacent to the "FMGC" indication.	The "A/C STATUS" page comes into view.

5. Close-up
Subtask 22-70-00-862-051-A

A. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 05:15:41 UTC