4. Fault Isolation
_______________
 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) (Ref. AMM TASK 34-42-33-000-001) and (Ref. AMM TASK 34-42-33-400-001).

 (2) If there is ground at pin AB/4F:

 - replace the LGCIU-1 (5GA1) (Ref. AMM TASK 32-31-71-000-001) and (Ref. AMM TASK 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) (Ref. ASM 34-42/01).

 (3) If there is ground at pin AB/6K:

 - replace the EIU-1 (1KS1) (Ref. AMM TASK 73-25-34-000-040) and (Ref. AMM TASK 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) (Ref. ASM 34-42/01).
 **ON A/C 001-004,
 Post SB 34-1171 For A/C 001-004,
 A. If the test gives the maintenance message
 LGCIU1(5GA1)/EIU1(1KS1)/RA1(2SA1):

 - 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) (Ref. AMM TASK 34-42-33-000-001) and (Ref. AMM TASK 34-42-33-400-001).

 (2) If there is ground at pin AB/4F:

 - replace the LGCIU-1 (5GA1) (Ref. AMM TASK 32-31-71-000-001) and (Ref. AMM TASK 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) (Ref. ASM 34-42/01).
 「一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一1 EFF : ALL ∞∞34-42-00∞∞∞∞∞∞∞∞∞∞Page 239
 Feb 01/05R CES

 (3) If there is ground at pin AB/6K:
 - replace the EIU-1 (1KS1) (Ref. AMM TASK 73-25-34-000-040) and (Ref. AMM TASK 73-25-34-400-040).
 (a) If there is still ground:
 - do a check and repair the wiring of the TEST INHIBIT discrete from the EIU1 (1KS1) to the RA transceiver 1 (2SA1) (Ref. ASM 34-42/01).
 B. Do the test given in para. 3.

 TASK 34-42-00-810-825
 RA2 Test Inoperative
 1. Possible Causes_______________
 - XCVR-RA, 2 (2SA2)

 - LGCIU-2 (5GA2)

 - EIU-2 (1KS2)

 - wiring of the GND/AIR LOGIC discrete from the LGCIU2 (5GA2) to the RA transceiver 2 (2SA2)

 - wiring of the FUNCTIONAL TEST INHIBIT discrete from the EIU2 (1KS2) to the RA transceiver 2 (2SA2)

 - wiring of the TEST INHIBIT discrete from the EIU2 (1KS2) to the RA
 transceiver 2 (2SA2)

 2. Job Set-up Information______________________
 A. Referenced Information
 -------------------------------------------------------------------------------
REFERENCE  DESIGNATION
 -------------------------------------------------------------------------------
AMM 32-31-71-000-001  Removal of the LGCIU (5GA1, 5GA2)
 AMM 32-31-71-400-001  Installation of the LGCIU (5GA1, 5GA2)
 AMM 34-42-00-740-002  BITE Test of the Radio Altimeter
 AMM 34-42-33-000-001  Removal of the Radio Altimeter Transceiver 2SA1 and 2SA2
 AMM 34-42-33-400-001  Installation of the Radio Altimeter Transceiver 2SA1 and 2SA2
 AMM 73-25-34-000-040  Removal of the Engine Interface Unit (EIU) (1KS1,1KS2)
 AMM 73-25-34-400-040  Installation of the Engine Interface Unit (EIU) (1KS1,1KS2)
 ASM 34-42/02
 3. Fault Confirmation__________________
 A. Test
 (1) Not applicable, the fault is evident.
 「一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一1 EFF : ALL ∞∞34-42-00∞∞∞∞∞∞∞∞∞∞Page 241
 Feb 01/05R
 CES  Post SB 34-1171 For A/C 001-004,

 A. Test
 (1) Do the BITE test of the radio altimeter (system 2) (Ref. AMM TASK 34-42-00-740-002).
 **ON A/C ALL
 4. Fault Isolation
_______________
 A. If you cannot start the RA2 test:
 - do a check for ground at pins AB/4F and AB/6K of the RA transceiver 2 (2SA2).
 (1) If there is no ground:

 - replace the XCVR-RA, 2 (2SA2) (Ref. AMM TASK 34-42-33-000-001) and (Ref. AMM TASK 34-42-33-400-001).

 (2) If there is ground at pin AB/4F: