DIR 1 - Loss of essential power (28VDC1 SPLY)

TASK 23-73-00-810-965-A
DIR 1 - Loss of essential power (28VDC1 SPLY)

1. Possible Causes

C/B-COM/CIDS/DIR ESS/1 [150RH]
DIR-CIDS, 1 [101RH]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-73-00-740-005	BITE-Test of the Cabin Intercommunication Data System (CIDS) through the CFDS
ASM 237306
AMM 23-73-34-000-001	Removal of the CIDS Director
AMM 23-73-34-400-001	Installation of the CIDS Director

3. Fault Confirmation
Subtask 23-73-00-865-052-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/CIDS/DIR ESS/1	150RH	G01

Subtask 23-73-00-700-055-A ** ON A/C NOT FOR ALL

B. Do the CIDS Interface and Power-Up test through the CFDS AMM 23-73-00-740-005.
(1) If you cannot close the circuit breaker (150RH), go to Para 4. B.

4. Fault Isolation
Subtask 23-73-00-810-751-A ** ON A/C NOT FOR ALL

A. If the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] is closed and the test confirmes the fault:

remove the DIR-CIDS, 1 [101RH]
AMM 23-73-34-000-001.
close the C/B-COM/CIDS/DIR ESS/1 [150RH] .
do a check for 28 VDC at the DIR connector AC/1
ASM 237306 and ASM 237306.

(1) If there is 28 VDC:

open the C/B-COM/CIDS/DIR ESS/1 [150RH] .
install a new DIR-CIDS, 1 [101RH] .
AMM 23-73-34-400-001.

(2) If there is no 28 VDC:

do a check for 28 VDC at the C/B-COM/CIDS/DIR ESS/1 [150RH] .

(a) If there is 28 VDC:

open the C/B-COM/CIDS/DIR ESS/1 [150RH] .
do a check of the wiring between the:
DIR-CIDS, 1 [101RH] connector AC/1 and C/B-COM/CIDS/DIR ESS/1 [150RH]
ASM 237306 and ASM 237306.

(b) If there is no 28 VDC:

replace the C/B-COM/CIDS/DIR ESS/1 [150RH] .
install the DIR-CIDS, 1 [101RH] .

Subtask 23-73-00-810-752-A ** ON A/C NOT FOR ALL

B. If the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] is open:

close this circuit breaker.

(1) If the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] trips:

remove the DIR-CIDS, 1 [101RH]
AMM 23-73-34-000-001.
do a check for a short to ground between the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] and the DIR-CIDS, 1 [101RH]
ASM 237306 and ASM 237306.

(a) If there is a short to ground:

repair the wiring .

(b) If there is no short to ground:

close the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] .

1 If the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] trips:

replace the C/B-COM/CIDS/DIR ESS/1 [150RH] .

2 If the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] stays closed:

open the circuit breaker C/B-COM/CIDS/DIR ESS/1 [150RH] .
install a new DIR-CIDS, 1 [101RH]
AMM 23-73-34-400-001.

5. Close-up
Subtask 23-73-00-942-051-A ** ON A/C NOT FOR ALL

A. Do the test given in Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:26:00 UTC