Removal of the Decoder/Encoder Unit B

TASK 23-73-47-000-001-A
Removal of the Decoder/Encoder Unit B

ZONE: 200
FIN: 300RH1
FIN: 300RH3 ** ON A/C NOT FOR ALL
FIN: 300RH4 ** ON A/C NOT FOR ALL
FIN: 300RH5 ** ON A/C NOT FOR ALL
FIN: 300RH6
FIN: 300RH7 ** ON A/C NOT FOR ALL
FIN: 300RH8 ** ON A/C NOT FOR ALL

1. Reason for the Job
Self Explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - BLANKING
No specific	AR	STEPLADDER 0.5 M (1.6 FT)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
200	UPPER HALF FUSELAGE
FOR [300RH1] (DEU-B)
221BC
FOR [300RH4] (DEU-B)
251KC
242QW
231JC
FOR [300RH5] (DEU-B)
FOR [300RH6] (DEU-B)
251KC
261CC
FOR [300RH6] (DEU-B)
251KC
242WW
FOR [300RH7] (DECODER/ENCODER UNIT B)
231JC
FOR [300RH7] (DECODER/ENCODER UNIT B)
FOR [300RH8] (DEU-B)
261CC

C. Referenced Information

REFERENCE	DESIGNATION
TASK 23-73-00-861-001-A	Energize the Cabin Intercommunication Data System (CIDS)
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 31-32-00-860-003-A	Procedure to Get Access to the SYSTEM REPORT/TEST/COM Page
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
Decoder/Encoder Unit B ** ON A/C NOT FOR ALL
FOR [300RH1] (DEU-B)
TASK 25-23-42-000-001-A	Removal of the Ceiling Panels - Forward Utility Area
FOR [300RH4] (DEU-B)
TASK 25-23-41-000-001-A	Removal of the Ceiling Panels
TASK 25-23-43-000-001-A	Removal of the Upper Sidewall Panel
FOR [300RH5] (DEU-B)
FOR [300RH6] (DEU-B)
TASK 25-23-41-000-001-A	Removal of the Ceiling Panels
TASK 25-23-42-000-002-A	Removal of the Ceiling Panels - Aft Utility Area
FOR [300RH6] (DEU-B)
TASK 25-23-41-000-001-A	Removal of the Ceiling Panels
TASK 25-23-48-000-001-A	Removal of the Cove Light Panel
FOR [300RH7] (DECODER/ENCODER UNIT B)
TASK 25-23-42-000-001-A	Removal of the Ceiling Panels - Forward Utility Area
FOR [300RH7] (DECODER/ENCODER UNIT B)
FOR [300RH8] (DEU-B)
TASK 25-23-42-000-002-A	Removal of the Ceiling Panels - Aft Utility Area

3. Job Set-up
Subtask 23-73-47-861-050-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 23-73-47-970-050-A

B. Trouble Shooting Data
(1) Make sure that the Cabin Intercommunication Data System (CIDS) is energized
(Ref. AMM TASK 23-73-00-861-001).
(2) If available, you can print the Trouble Shooting Data (TSD) as follows:

Get access to the SYSTEM REPORT/TEST COM page (Ref. AMM TASK 31-32-00-860-003).
On this page, push the line key adjacent to the CIDS1 (2) indication.
On the CIDS1 (2) page, push the line key adjacent to the TROUBLE SHOOTING DATA indication to get the TROUBLE SHOOTING DATA page.
Print the Trouble Shooting Data page.

Subtask 23-73-47-865-053-A

C. Open, safety and tag these circuit breakers in this sequence:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	COM/CIDS/DEU B/BAT	143RH	N12
** ON A/C NOT FOR ALL
49VU	COM/CIDS/DEU B/ESS	153RH	G03
** ON A/C NOT FOR ALL
121VU	COM NAV/CIDS/DEU B/NORM	162RH	M09
** ON A/C NOT FOR ALL
121VU	COM NAV/CIDS/DEU B/NORM	162RH	M08
** ON A/C NOT FOR ALL
121VU	COM / CIDS / DEU B / NORM FWD	193RH	M09
2001VU	CIDS-DEU B-NORM-AFT	194RH	C08
** ON A/C NOT FOR ALL
121VU	COM/CIDS/DEU B BAT/L	719RH	Q10
121VU	COM/CIDS/DEU B BAT/R	720RH	Q11
49VU	COM/CIDS/DEU B ESS/L	419RH	G04
49VU	COM/CIDS/DEU B ESS/R	420RH	G05
121VU	COM NAV/CIDS/DEU B NORM/L	619RH	M07
121VU	COM NAV/CIDS/DEU B NORM/R	620RH	M08
** ON A/C NOT FOR ALL
2000VU	WATER SYSTEM-QANT-IND	1MA	B01
** ON A/C NOT FOR ALL
2001VU	WATER SYS-QUANT-IND	1MA	B06
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	23MG	A05
** ON A/C ALL
2001VU	VACU TOIL SYS-LAV PWR-A	32MG	A01
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACU-GEN	33MG	A08
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACUUM-GEN	33MG	A08
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-M	34MG	A04
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-G	34MG	A04
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-E	34MG	A04
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACU-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACUUM-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-F	39MG	A03
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-D	39MG	A03
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	45MG	A02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-D	45MG	A02
** ON A/C NOT FOR ALL
2001VU	WATER SYS-DRAIN	1MP	B05
** ON A/C NOT FOR ALL
2001VU	WATER-SYS-DRAIN	1MP	B05

Subtask 23-73-47-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put a STEPLADDER 0.5 M (1.6 FT) below the related access panel.
(2) Remove the forward utility-area ceiling panel.

(a) FOR [300RH1] (DEU-B)
remove 221BC (Ref. AMM TASK 25-23-42-000-001)

(3) Remove the upper sidewall panel.

(a) FOR [300RH4] (DEU-B)
remove 242QW (Ref. AMM TASK 25-23-43-000-001)

(4) Remove the aft utility-area ceiling panel.
(a) FOR [300RH5] (DEU-B), [300RH6] (DEU-B)
remove 261CC (Ref. AMM TASK 25-23-42-000-002)

Subtask 23-73-47-010-050-B ** ON A/C NOT FOR ALL

D. Get Access
(1) Put a STEPLADDER 0.5 M (1.6 FT) below the related access panel.
(2) Remove the forward utility-area ceiling panel.

(a) FOR [300RH1] (DEU-B)
remove 221BC

(b) FOR [300RH7] (DECODER/ENCODER UNIT B)
remove 231JC (Ref. AMM TASK 25-23-42-000-001)

(3) Remove the aft utility-area ceiling panel.

(a) FOR [300RH4] (DEU-B)
remove 251KC

(b) FOR [300RH5] (DEU-B), [300RH6] (DEU-B)
remove 261CC (Ref. AMM TASK 25-23-42-000-002)

Subtask 23-73-47-010-050-J ** ON A/C NOT FOR ALL

D. Get Access
(1) Put a STEPLADDER 0.5 M (1.6 FT) below the related access panel.
(2) Removal of the forward utility area - ceiling panel:
(a) FOR [300RH1] (DEU-B)
remove 221BC (Ref. AMM TASK 25-23-42-000-001).
(3) Removal of the related ceiling panel:
(a) FOR [300RH4] (DEU-B)
remove 231JC (Ref. AMM TASK 25-23-41-000-001).
(b) FOR [300RH5] (DEU-B), [300RH6] (DEU-B)
remove 251KC (Ref. AMM TASK 25-23-41-000-001).
(4) Removal of the related aft utility area - ceiling panel:
(a) FOR [300RH7] (DECODER/ENCODER UNIT B), [300RH8] (DEU-B)
remove 261CC (Ref. AMM TASK 25-23-42-000-002).

Subtask 23-73-47-010-050-M ** ON A/C NOT FOR ALL

D. Get Access
(1) Put a STEPLADDER 0.5 M (1.6 FT) below the related access panel.
(2) Removal of the forward utility area - ceiling panel:
(a) FOR [300RH1] (DEU-B)
remove 221BC (Ref. AMM TASK 25-23-42-000-001).
(3) Removal of the related ceiling panel:
(a) FOR [300RH4] (DEU-B)
remove 231JC (Ref. AMM TASK 25-23-41-000-001).
(b) FOR [300RH6] (DEU-B)
remove 251KC (Ref. AMM TASK 25-23-41-000-001).
(4) Removal of the related aft utility area - ceiling panel:
(a) FOR [300RH7] (DECODER/ENCODER UNIT B), [300RH8] (DEU-B)
remove 261CC (Ref. AMM TASK 25-23-42-000-002).

Subtask 23-73-47-010-050-N ** ON A/C NOT FOR ALL

D. Get Access
(1) Put a STEPLADDER 0.5 M (1.6 FT) below the related access panel.
(2) Removal of the forward utility area - ceiling panel:
(a) FOR [300RH1] (DEU-B)
remove 221BC (Ref. AMM TASK 25-23-42-000-001).
(3) Removal of the related cove light panel:
(a) FOR [300RH6] (DEU-B)
remove 242WW (Ref. AMM TASK 25-23-48-000-001).
(4) Removal of the related aft utility area - ceiling panel:
(a) FOR [300RH7] (DECODER/ENCODER UNIT B), [300RH8] (DEU-B)
remove 261CC (Ref. AMM TASK 25-23-42-000-002).

Subtask 23-73-47-010-050-Q ** ON A/C NOT FOR ALL

4. Procedure

CAUTION: MAKE MATCH MARKS ON ALL THE ELECTRICAL WIRES BEFORE YOU DISCONNECT THEM. IF YOU MAKE AN ERROR WHEN YOU CONNECT THE WIRES YOU WILL CAUSE DAMAGE TO EQUIPMENT.

Subtask 23-73-47-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Decoder/Encoder Unit (DEU) B

Decoder/Encoder Unit B ** ON A/C NOT FOR ALL

(1) Remove the locking spring (7) and disconnect the electrical connectors (2) and (3).
(2) Press the locking catch (5) and carefully remove the DEU B (1) from the mounting tray (6).
(3) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.

Subtask 23-73-47-020-051-B ** ON A/C NOT FOR ALL

A. Removal of the Decoder/Encoder Unit (DEU) B

Decoder/Encoder Unit B ** ON A/C NOT FOR ALL

(1) Do not disconnect the electrical connector (7) from the connection/termination box (4).
(2) Release the spring latches (1) and disconnect the electrical connectors (2).
(3) Release the nylatches (3) and remove the connection/termination box (4).
(4) Make sure that you do not change the position of the coding switches and record them.
(5) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(6) Release the nylatches (5) and remove the DEU B (6).

[Rev.10 from 2021] 2026.04.02 06:12:36 UTC