Loss of the BMC 1 and BMC 2 Buses of the SDAC 2

TASK 31-54-00-810-943-A
Loss of the BMC 1 and BMC 2 Buses of the SDAC 2

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-50-00-710-001	Ground Scanning of the Central Warning System
ASM 315403
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC

3. Fault Confirmation
Subtask 31-54-00-865-140-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 1/CTL	3HA1	D12
49VU	AIR BLEED/ENG 1/MONG	2HA1	D11
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 2/MONG	3HA2	D12
49VU	AIR BLEED/ENG 1/CTL	2HA1	D11
** ON A/C NOT FOR ALL
122VU	AIR BLEED/ENG 2/CTL	3HA2	Z23
122VU	AIR BLEED/ENG 2/MONG	2HA2	Z22
** ON A/C NOT FOR ALL
122VU	AIR BLEED/ENG 1/MONG	3HA1	Z23
122VU	AIR BLEED/ENG 2/CTL	2HA2	Z22

Subtask 31-54-00-710-319-A

B. Test
Do the ground scanning of the central warning systems AMM 31-50-00-710-001.

4. Fault Isolation
Subtask 31-54-00-810-192-A

A. If the test gives the maintenance message SDAC 2 : NO DATA FROM BMC 1+2:

(1) If the fault continues:

do a check and repair as necessary the wiring from the SDAC 2 (1WV2)
. pins AB/12G, 12H to the first terminal block
. pins AE/12C, 12D to the first terminal block ASM 315403.

Subtask 31-54-00-710-320-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:30:33 UTC