Loss of the Aural Advisories in the Loud Speaker(s)

TASK 34-43-00-810-827-A
Loss of the Aural Advisories in the Loud Speaker(s)

1. Possible Causes

LOUD SPEAKER-CAPT [7WW]
wiring of the CAPT loud speaker (7WW)
LOUD SPEAKER-F/O [8WW]
wiring of the F/O loud speaker (8WW)
CMPTR-TCAS [1SG]
RELAY-RCDR/CVR TEST (20RK)
wiring of the AUDIO OUTPUT discretes from the TCAS computer (1SG) to the RCDR/CVR test relay (20RK)
wiring of the RCDR/CVR test relay (20RK)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-53-00-810-922-A	Failure of the Captain Loud Speaker
TSM TASK 31-53-00-810-923-A	Failure of the First Officer Loud Speaker
AMM 31-53-21-000-001	Removal of the Loudspeakers
AMM 31-53-21-400-001	Installation of the Loudspeakers
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

3. Fault Confirmation
Subtask 34-43-00-740-096-A

A. Test
(1) Do the BITE test of the TCAS AMM 34-43-00-740-001 and make sure that you can hear the synthesized voice message in the two loud speakers.

4. Fault Isolation
Subtask 34-43-00-810-078-A

A. If you cannot hear the synthesized voice message:
(1) In the CAPT loud speaker only:

(a) If the fault continues:

do a check and repair the wiring of the CAPT loud speaker (7WW):
. pin A/R to the first terminal block
. pin A/S to the first terminal block
ASM 344301.

(2) In the F/O loud speaker only:

(a) If the fault continues:

do a check and repair the wiring of the F/O loud speaker (8WW):
. pin A/R to the first terminal block
. pin A/S to the first terminal block
ASM 344301.

(3) In the two loud speakers:

(a) If the fault continues:

1 If the fault continues:

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

a If there is no continuity:

b If there is continuity:

do a check and repair the wiring of the RCDR/CVR test relay (20RK):
. pin A/B to the first terminal block
. pin A/C to the first terminal block
ASM 344301.

(b) If the fault continues:

Subtask 34-43-00-740-097-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:13 UTC