Loss of the Signal between the DLRB and the DLS

TASK 31-38-00-810-810-A
Loss of the Signal between the DLRB and the DLS

1. Possible Causes

ROUTING BOX-DATA LOADING [102TD]
SELECTOR-DATA LOADING [101TD]
wiring
MDDU [1TD]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 313801
AMM 31-38-21-000-001	Removal of the Data Loading Selector
AMM 31-38-21-400-001	Installation of the Data Loading Selector
AMM 31-38-34-000-001	Removal of the Data Loading Routing Box (DLRB)
AMM 31-38-34-400-001	Installation of the Data Loading Routing Box (DLRB)

3. Fault Confirmation
Subtask 31-38-00-740-053-A ** ON A/C NOT FOR ALL

A. Not applicable, the fault is evident.

4. Fault Isolation
Subtask 31-38-00-810-059-B ** ON A/C NOT FOR ALL

A. If the fault is identified by the crew observation:

UP-LOADING ERROR indication on the display of the Data Loading Selector
(1) If the fault continues:

Replace the ROUTING BOX-DATA LOADING [102TD] AMM 31-38-34-000-001 and AMM 31-38-34-400-001.

(2) If the fault continues:

Replace the SELECTOR-DATA LOADING [101TD] AMM 31-38-21-000-001 and AMM 31-38-21-400-001.

(3) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and MDDU [1TD] ASM 313801:
(a) Pin B/19, 35 (102TD) to pin A/1, 2 (1TD).
(b) Pin B/18, 34 (102TD) to pin A/8, 9 (1TD).
(c) Pin B/2 (102TD) to pin A/18 (1TD).
(d) Pin B/23 (102TD) to pin A/50 (1TD).
(e) Pin B/22 (102TD) to pin A/51 (1TD).
(f) Pin B/21 (102TD) to pin A/52 (1TD).
(g) Pin B/20 (102TD) to pin A/53 (1TD).

Subtask 31-38-00-810-059-C ** ON A/C NOT FOR ALL

A. If the fault is identified by the crew observation:

UP-LOADING ERROR indication on the display of the Data Loading Selector

Do again a check of the ROUTING BOX-DATA LOADING [102TD] by another media (if available).

(1) If the fault continues:

Replace the ROUTING BOX-DATA LOADING [102TD] AMM 31-38-34-000-001 and AMM 31-38-34-400-001.

(2) If the fault continues:

Replace the SELECTOR-DATA LOADING [101TD] AMM 31-38-21-000-001 and AMM 31-38-21-400-001.

(3) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and connector (2TD) ASM 313801:
(a) Pin B/19, 35 (102TD) to pin A/1, 2 (2TD).
(b) Pin B/18, 34 (102TD) to pin A/8, 9 (2TD).
(c) Pin B/2 (102TD) to pin A/19 (2TD).
(d) Pin B/23 (102TD) to pin A/50 (2TD).
(e) Pin B/22 (102TD) to pin A/51 (2TD).
(f) Pin B/21 (102TD) to pin A/52 (2TD).
(g) Pin B/20 (102TD) to pin A/53 (2TD).

[Rev.8 from Aug 2018] 2026.04.04 04:30:08 UTC