All CVR Channels inaudible

TASK 23-71-00-810-811-A
All CVR Channels inaudible

1. Possible Causes

wiring
CVR [1RK]
AMU [1RN]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-51-34-000-001	Removal of the Audio Management Unit (AMU) (1RN)
AMM 23-51-34-400-001	Installation of the Audio Management Unit (AMU) (1RN)
AMM 23-71-00-710-001	Operational Test of the CVR and the CVR Channel Recording
ASM 237102
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

3. Fault Confirmation
Subtask 23-71-00-710-067-A

A. Test
(1) Do the operational test of CVR channel AMM 23-71-00-710-001.

4. Fault Isolation
Subtask 23-71-00-810-059-A

A. If there is confirmation of the fault:

NOTE: This fault isolation is applicable to the Captain station. Apply this fault isolation test to the others stations. Use the indications in parentheses.

(1) Do a check and repair of the wiring between the JACK-CVR/HEAD SET (22RK) and the CVR [1RK] ASM 237102.
(2) If the fault continues:
(a) Replace the AMU [1RN] AMM 23-51-34-000-001 AMM 23-51-34-400-001.
(3) If the fault continues:
(a) Do a check and repair of the wiring of the CAPT (F/O, 3rd OCCPT) channel between the AMU [1RN] and the CVR [1RK] ASM 237102.
(4) If the fault continues:

Do a check and repair of the wiring between the JACK-CVR/HEAD SET (22RK) and the CVR [1RK] ASM 237102.

Subtask 23-71-00-810-062-A

B. If there is no confirmation of the fault:
(1) Replace the CVR [1RK] AMM 23-71-35-000-001 AMM 23-71-35-400-001.

Subtask 23-71-00-710-068-A

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:48 UTC