Loss of the Transmission from the Captain Oxygen Mask Microphone

TASK 23-51-00-810-848-A
Loss of the Transmission from the Captain Oxygen Mask Microphone

1. Possible Causes

STOWAGE BOX-OXY MASK, CAPT [10RN1]
AMU [1RN]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-51-00-710-001	Operational Test of the Audio Management
ASM 235102
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 35-12-41-000-001	Removal of the Oxygen-Mask Stowage-Box
AMM 35-12-41-400-001	Installation of the Oxygen-Mask Stowage-Box

3. Fault Confirmation
Subtask 23-51-00-710-096-A

A. Test
(1) Do the operational test of the audio management system AMM 23-51-00-710-001.

4. Fault Isolation
Subtask 23-51-00-810-097-A

A. After you speak in the microphone of the Captain Oxygen Mask:
(1) If the reception is incorrect at each loud speaker and Oxygen Mask Mike of each crew station:

Replace the STOWAGE BOX-OXY MASK, CAPT [10RN1] AMM 35-12-41-000-001 and AMM 35-12-41-400-001.

(a) If the fault continues:

Replace the AMU [1RN] AMM 23-51-34-000-001 and AMM 23-51-34-400-001

1 If the fault continues:

Do a check and repair the wiring from the STOWAGE BOX-OXY MASK, CAPT [10RN1] to the AMU [1RN] ASM 235102

Subtask 23-51-00-710-097-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:46 UTC