Loss of the RA/TA DISPLAY 1 Bus Identified by the EIS1

TASK 34-43-00-810-803-A
Loss of the RA/TA DISPLAY 1 Bus Identified by the EIS1

1. Possible Causes

CMPTR-TCAS [1SG]
wiring of the RA/TA DISPLAY 1 bus from the TCAS computer (1SG) to the first terminal block

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-60-00-740-002	Perform Electronic Instrument System (EIS) Input Test
AMM 31-60-00-740-007	GROUND SCANNING Test of the DMC
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 34-43-00-865-067-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	COM NAV/TCAS	4SG	K10

Subtask 34-43-00-740-052-A ** ON A/C NOT FOR ALL

B. Test
(1) Do the EIS input test AMM 31-60-00-740-002.

Subtask 34-43-00-740-052-B ** ON A/C NOT FOR ALL

B. Test
(1) Do the Ground Scanning Test of the DMC AMM 31-60-00-740-007.

4. Fault Isolation
Subtask 34-43-00-810-053-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DMC1 : NO TCAS DATA:

(1) If the fault continues:

do a check and repair the wiring of the RA/TA DISPLAY 1 bus from the TCAS computer (1SG) to the first terminal block ASM 344301.

Subtask 34-43-00-810-053-C ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DMC1 : TCAS(1SG)/DMC1(1WT1)

(1) If the fault continues:

do a check and repair the wiring of the RA/TA DISPLAY 1 bus from the TCAS computer (1SG) to the first terminal block ASM 344301.

Subtask 34-43-00-740-053-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:12 UTC