Loss of the Bus Output from the Cockpit Voice Recorder (CVR) to the CFDIU

TASK 31-32-00-810-950-A
Loss of the Bus Output from the Cockpit Voice Recorder (CVR) to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-71-35-000-001	Removal of the Cockpit Voice Recorder (CVR) 1RK
AMM 23-71-35-400-001	Installation of the Cockpit Voice Recorder (CVR) 1RK
AMM 31-32-00-869-002	Procedure for the Class 3 Fault Reading
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU

3. Fault Confirmation
Subtask 31-32-00-875-052-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/CVR/SPLY	23RK	E14
49VU	COM/CVR/CTL	26RK	E13
121VU	CFDS/CFDIU/SPLY	2TW	J18
121VU	CFDS/CFDIU/BACK/UP	8TW	J17

Subtask 31-32-00-740-326-A ** ON A/C NOT FOR ALL

B. Test
On the CFDS MENU page, get access to the AVIONICS STATUS page AMM 31-32-00-869-002.

4. Fault Isolation
Subtask 31-32-00-810-206-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message NO CVR DATA:

(1) If the fault continues:

(a) If the fault continues:

do a check and repair the wiring from the CFDIU (1TW) to the CVR (1RK) from pins AA/12H to first terminal block.

5. Close-up
Subtask 31-32-00-740-327-A ** ON A/C NOT FOR ALL

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

[Rev.8 from Aug 2018] 2026.04.04 04:29:59 UTC