Permanent noise from the cockpit loudspeaker(s)

TASK 34-43-00-810-871-A
Permanent noise from the cockpit loudspeaker(s)

1. Possible Causes

CMPTR-TCAS [1SG]
CTL UNIT-ATC/TCAS [3SH]
wiring of the AUDIO OUTPUT discretes from the TCAS computer (1SG) to the RCDR/CVR test relay (20RK)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-43-00-740-001	BITE Test of the TCAS
ASM 344301
AMM 34-43-34-000-001	Removal of the TCAS Computer
AMM 34-43-34-400-001	Installation of the TCAS Computer
AMM 34-52-12-000-001	Removal of the ATC/TCAS Control Unit
AMM 34-52-12-400-001	Installation of the ATC/TCAS Control Unit

3. Fault Confirmation
Subtask 34-43-00-700-051-A

A. Test
Not applicable, the fault is evident.

4. Fault Isolation
Subtask 34-43-00-810-133-A

A. If there is the noise:

(1) If the fault continues:

(a) If the fault continues:

do a check and repair the wiring of the AUDIO OUTPUT discretes from the TCAS computer (1SG) to the RCDR/CVR test relay (20RK) ASM 344301.

Subtask 34-43-00-740-183-A

B. Do the BITE test of the TCAS AMM 34-43-00-740-001.

[Rev.8 from Aug 2018] 2026.04.04 04:33:14 UTC