DMU Receives No Data from the FCDC 1 or FCDC 2

TASK 31-36-00-810-824-A
DMU Receives No Data from the FCDC 1 or FCDC 2

1. Possible Causes

wiring
FCDC-1 [3CE1]
FCDC-2 [3CE2]
DMU [1TV]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 27-96-00-710-001	Operational Test of the FCDC
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 31-36-00-740-074-A ** ON A/C NOT FOR ALL

A. Do the DMU (1TV) fault monitoring test AMM 31-36-00-710-001.

NOTE: Make sure that the circuit breakers 1TV, 20CE2 on the panel 121VU and 20CE1 on the panel 49VU are closed during the test.

4. Fault Isolation
Subtask 31-36-00-810-064-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message:

NO FCDC 1 DATA, or
NO FCDC 2 DATA

(1) Do the operational test of the FCDC AMM 27-96-00-710-001.

(a) If the test gives a different maintenance message, you can find the related trouble shooting procedure in the applicable Page Block 201.

(2) If the fault continues:

do a check and repair the wiring from the FCDC-1 [3CE1] or FCDC-2 [3CE2] to the DMU [1TV] ASM 313701:

FCDC 1 Connector AA/5E to DMU Connector AA/3C
FCDC 1 Connector AA/5F to DMU Connector AA/3D
or
FCDC 2 Connector AB/5E to DMU Connector AB/3C
FCDC 2 Connector AB/5F to DMU Connector AB/3D

(3) If the fault continues:

replace the DMU (1TV) AMM 31-36-34-000-001 and AMM 31-36-34-400-001.

Subtask 31-36-00-740-075-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:30:03 UTC