Failure of the Suppressor Coaxial Cables of the TCAS

TASK 34-43-00-810-828-A
Failure of the Suppressor Coaxial Cables of the TCAS

1. Possible Causes

coaxial cable from the TCAS computer (1SG) to the ATC/Mode S transponder 1 (1SH1)
coaxial cable from the TCAS computer (1SG) to the ATC/Mode S transponder 2 (1SH2)
coaxial cable from the TCAS computer (1SG) to the DME interrogator 1 (2SD1)
coaxial cable from the TCAS computer (1SG) to the DME interrogator 2 (2SD2)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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 34-51-33-000-001	Removal of the DME Interrogator
AMM 34-51-33-400-001	Installation of the DME Interrogator
AMM 34-52-33-000-001	Removal of the ATC/Mode S Transponder
AMM 34-52-33-400-001	Installation of the ATC/Mode S Transponder

3. Fault Confirmation
Subtask 34-43-00-700-050-A

A. Test
Not applicable, you cannot confirm this fault on the ground.

4. Fault Isolation
Subtask 34-43-00-810-080-A

A. If the fault symptom is identified by the crew observation on the ND,
TCAS-amber filled circle on the aircraft symbol
or
TCAS-false intruders:

remove the TCAS computer (1SG) AMM 34-43-34-000-001
remove the ATC/Mode S transponder 1 (1SH1) AMM 34-52-33-000-001.
do a check of the coaxial cable from the TCAS computer (1SG) to the ATC/Mode S transponder 1 (1SH1) ASM 344301.

(1) If there is no continuity:

(2) If there is continuity:

make sure that there is no continuity between the core and the shield of the coaxial cable.

(a) If there is continuity:

(b) If there is no continuity:

install the ATC/Mode S transponder 1 (1SH1)
remove the ATC/Mode S transponder 2 (1SH2) AMM 34-52-33-000-001
do a check of the coaxial cable from the TCAS computer (1SG) to the ATC/Mode S transponder 2 (1SH2).

1 If there is no continuity:

2 If there is continuity:

make sure that there is no continuity between the core and the shield of the coaxial cable.

a If there is continuity:

b If there is no continuity:

install the ATC/Mode S transponder 2 (1SH2)
remove the DME interrogator 1 (2SD1) AMM 34-51-33-000-001
do a check of the coaxial cable from the TCAS computer (1SG) to the DME interrogator 1 (2SD1).
If there is no continuity:
replace the coaxial cable
install the DME interrogator 1 (2SD1) AMM 34-51-33-400-001
install the TCAS computer (1SG).
If there is continuity:
make sure that there is no continuity between the core and the shield of the coaxial cable.
. If there is continuity:
replace the coaxial cable
install the DME interrogator 1 (2SD1)
install the TCAS computer (1SG).
. If there is no continuity:
install the DME interrogator 1 (2SD1)
remove the DME interrogator 2 (2SD2) AMM 34-51-33-000-001
do a check of the coaxial cable from the TCAS computer (1SG) to the DME interrogator 2 (2SD2).
* If there is no continuity:
replace the coaxial cable
install the DME interrogator 2 (2SD2)
install the TCAS computer (1SG).
* If there is continuity:
make sure that there is no continuity between the core and the shield of the coaxial cable.
** If there is continuity:
replace the coaxial cable
install the DME interrogator 2 (2SD2)
install the TCAS computer (1SG).

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