RA1 Test Inoperative

TASK 34-42-00-810-824-A
RA1 Test Inoperative

1. Possible Causes

XCVR-RA, 1 [2SA1]
LGCIU-1 [5GA1]
wiring of the GND/AIR LOGIC discrete from the LGCIU1 (5GA1) to the RA transceiver 1 (2SA1)
EIU-1 [1KS1]
wiring of the FUNCTIONAL TEST INHIBIT discrete from the EIU1 (1KS1) to the RA transceiver 1 (2SA1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
ASM 344201
AMM 34-42-33-000-001	Removal of the Radio Altimeter Transceiver
AMM 34-42-33-400-001	Installation of the Radio Altimeter Transceiver
AMM 73-25-34-000-040	Removal of the Engine Interface Unit (EIU)
AMM 73-25-34-000-041	Removal of the Engine Interface Unit (EIU)
AMM 73-25-34-400-040	Installation of the Engine Interface Unit (EIU)
AMM 73-25-34-400-041	Installation of the Engine Interface Unit (EIU)

3. Fault Confirmation
Subtask 34-42-00-740-102-A

A. Test
Not applicable, the fault is evident.

4. Fault Isolation
Subtask 34-42-00-810-075-A ** ON A/C NOT FOR ALL

A. If you cannot start the RA1 test:

do a check for ground at pins AB/4F and AB/6K of the RA transceiver 1 (2SA1).

(1) If there is no ground:

replace the XCVR-RA, 1 [2SA1] AMM 34-42-33-000-001 and AMM 34-42-33-400-001.

(2) If there is ground at pin AB/4F:

replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

(a) If there is still ground:

do a check and repair the wiring of the GND/AIR LOGIC discrete from the LGCIU1 (5GA1) to the RA transceiver 1 (2SA1) ASM 344201.

(3) If there is ground at pin AB/6K:

replace the EIU-1 [1KS1] AMM 73-25-34-000-040 and AMM 73-25-34-400-040.

(a) If there is still ground:

do a check and repair the wiring of the FUNCTIONAL TEST INHIBIT discrete from the EIU1 (1KS1) to the RA transceiver 1 (2SA1) ASM 344201.

Subtask 34-42-00-810-075-B ** ON A/C NOT FOR ALL

A. If you cannot start the RA1 test:

do a check for ground at pins AB/4F and AB/6K of the RA transceiver 1 (2SA1).

(1) If there is no ground:

replace the XCVR-RA, 1 [2SA1] AMM 34-42-33-000-001 and AMM 34-42-33-400-001.

(2) If there is ground at pin AB/4F:

replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

(a) If there is still ground:

do a check and repair the wiring of the GND/AIR LOGIC discrete from the LGCIU1 (5GA1) to the RA transceiver 1 (2SA1) ASM 344201.

(3) If there is ground at pin AB/6K:

replace the EIU-1 [1KS1] AMM 73-25-34-000-041 and AMM 73-25-34-400-041.

(a) If there is still ground:

do a check and repair the wiring of the FUNCTIONAL TEST INHIBIT discrete from the EIU1 (1KS1) to the RA transceiver 1 (2SA1) ASM 344201.

Subtask 34-42-00-740-104-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:09 UTC