The OFF Legend of the ADR3 Pushbutton Switch does not come on

TASK 34-13-00-810-920-A
The OFF Legend of the ADR3 Pushbutton Switch does not come on

1. Possible Causes

ADIRU-3 [1FP3]
BOARD-ANN LT TEST & INTFC [4LP]
wiring of the ADR OFF discrete from the ADIRU3 (1FP3) to the annunciator light test and interface board (4LP)
CDU-ADIRS [2FP]
wiring of the ADR OFF CMD discrete from the ADIRU3 (1FP3) to the ADIRS CDU (2FP)
wiring of the annunciator light test and interface board (4LP)
wiring
P/BSW-ADIRS/ADR3 (26FP3)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 33-14-33-000-001	Removal of the Annunciator-Light Test and Interface-Board
AMM 33-14-33-400-001	Installation of the Annunciator-Light Test and Interface-Board
AMM 34-10-00-860-002	ADIRS Start Procedure
AMM 34-10-00-860-005	ADIRS Stop Procedure
AMM 34-12-12-000-001	Removal of the ADIRS CDU
AMM 34-12-12-400-001	Installation of the ADIRS CDU
AMM 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU
ASM 341302

3. Fault Confirmation
Subtask 34-13-00-860-060-A

A. Job Set-Up
(1) Do the ADIRS start procedure AMM 34-10-00-860-002.

Subtask 34-13-00-710-143-A ** ON A/C NOT FOR ALL

B. Test
(1) On the ADIRS CDU, push the ADR 3 pushbutton switch and make sure that the OFF legend comes on.

Subtask 34-13-00-710-143-B ** ON A/C NOT FOR ALL

B. Test
(1) On the ADIRS MSU, push the ADR 3 pushbutton switch and make sure that the OFF legend comes on.

4. Fault Isolation
Subtask 34-13-00-810-170-A ** ON A/C NOT FOR ALL

A. If the OFF legend of the ADR 3 pushbutton switch does not come on:

on the overhead control and indicating panel 25VU, set the INT LT/ANN LT switch to TEST and make sure that the OFF legend comes on.

(1) If the OFF legend comes on:

replace the ADIRU-3 [1FP3] AMM 34-12-34-000-001 and AMM 34-12-34-400-001.

(a) If the OFF legend stays off when the ADR 3 pushbutton switch is pushed:

replace the BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

1 If the fault continues:

do a check of the wiring of the ADR OFF discrete from the ADIRU3 (1FP3) to the annunciator light test and interface board (4LP) ASM 341302.

a If there is no continuity:

repair the above wiring.

b If there is continuity:

replace the CDU-ADIRS [2FP] AMM 34-12-12-000-001 and AMM 34-12-12-400-001.

. If the fault continues:
- do a check and repair the wiring of the ADR OFF CMD discrete from the ADIRU3 (1FP3) to the ADIRS CDU (2FP) ASM 341302.

(2) If the OFF legend does not come on:

replace the BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

(a) If the fault continues:

replace the CDU-ADIRS [2FP] AMM 34-12-12-000-001 and AMM 34-12-12-400-001.

1 If the fault continues:

do a check and repair the wiring of the annunciator light test and interface board (4LP):
. from pin A/13 to ADIRS CDU (2FP) pin C/21
. from pin A/15 to pin A/11
. from pin A/12 to the first terminal block
ASM 341302.

Subtask 34-13-00-810-170-B ** ON A/C NOT FOR ALL

A. If the OFF legend of the ADR 3 pushbutton switch does not come on:

On the overhead control and indicating panel 25VU, set the INT LT/ANN LT switch to TEST and make sure that the OFF legend comes on.

(1) If the OFF legend comes on:

Replace the ADIRU-3 [1FP3] AMM 34-12-34-000-001 and AMM 34-12-34-400-001.

(a) If the OFF legend stays off when the ADR 3 pushbutton switch is pushed:

Replace the BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

1 If the fault continues:

Do a check of the wiring of the ADR OFF discrete from the ADIRU3 (1FP3) to the annunciator light test and interface board (4LP) ASM 341302.

a If there is no continuity:

Repair the wiring.

b If there is continuity:

Replace the P/BSW-ADIRS/ADR3 (26FP3).

* If the fault continues:
* - Do a check and repair the wiring from pin AA/4C of the ADIRU3 (1FP3) to pin A/A1 of the ADIRS/ADR3 puhbutton switch (26FP3) ASM 341302.

(2) If the OFF legend does not come on:

Replace the BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

(a) If the fault continues:

Replace the P/BSW-ADIRS/ADR3 (26FP3).

1 If the fault continues:

Do a check and repair the wiring of the annunciator light test and interface board (4LP) :
. From pin A/13 to pin A/4 of the ADIRS/ADR3 pushbutton switch (26FP3)
. From pin A/15 to pin A/11
. From pin A/12 to the first terminal block
ASM 341302.

Subtask 34-13-00-710-144-A

B. Do the test given in Para. 3.

5. Close-up
Subtask 34-13-00-860-061-A

A. Put the aircraft back to its initial configuration.
(1) On the panel 25VU, set the ANN LT switch to BRT.
(2) Do the ADIRS stop procedure AMM 34-10-00-860-005.

[Rev.8 from Aug 2018] 2026.04.04 04:32:28 UTC