DMU receives no Data from the ZC

TASK 21-63-00-810-828-A
DMU receives no Data from the ZC

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-63-00-710-004	Operational Test of the Cockpit and Cabin Temperature Control with CFDS/MCDU
ASM 216303
AMM 31-36-00-710-001	Test of the DMU
AMM 31-36-34-000-001	Removal of the Data Management Unit (DMU)
AMM 31-36-34-400-001	Installation of the Data Management Unit (DMU)
ASM 313701

3. Fault Confirmation
Subtask 21-63-00-710-105-A ** ON A/C NOT FOR ALL

A. Do the Test of the DMU AMM 31-36-00-710-001.

NOTE: Make sure that the circuit breakers 1HK, 2HK, 3HK and 4HK are closed during the test.

4. Fault Isolation
Subtask 21-63-00-810-111-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message NO ZONE CTRL DATA:

do the operational test of the cockpit and cabin temperature-control system with CFDS/MCDU AMM 21-63-00-710-004.

(1) If the test gives a different maintenance message, do the related trouble shooting procedure.
(2) If the fault continues:

(3) If the fault continues:

do a check and repair the wiring of the signal ARINC 429 XTR EXT from the ZC (8HK) to the DMU (1TV) ASM 216303 and ASM 313701.

Subtask 21-63-00-710-106-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

5. Close-up
Subtask 21-63-00-860-077-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:25:03 UTC