W DOC AIRBUS | TSM A320F

Loss of the MCDU 1 FAIL Discrete

TASK 22-82-00-810-809-A
Loss of the MCDU 1 FAIL Discrete

1. Possible Causes
  • FMGC-1 [1CA1]
  • wiring of the MCDU OWN FAIL discrete from the FMGC 1 (1CA1) to the first terminal block
  • FMGC-2 [1CA2]
  • wiring of the MCDU OPP FAIL discrete from the FMGC 2 (1CA2) to the first terminal block
  • MCDU-1 [3CA1]
  • wiring of the MCDU FAIL discrete from the MCDU 1 (3CA1) to the first terminal block
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 22-82-12-000-001
Removal of the MCDU
AMM 22-82-12-400-002
Installation of the MCDU
AMM 22-83-34-000-001
Removal of the FMGC
AMM 22-83-34-400-001
Installation of the FMGC
ASM 228504
AMM 22-96-00-710-001
Operational Test of the AFS
3. Fault Confirmation
Subtask 22-82-00-710-066-A
A. Test
   (1) Do the operational test of the AFS AMM 22-96-00-710-001, read the result for the FMGC 1 and the FMGC 2 and do one of these three fault isolation steps (A., B. or C.).
4. Fault Isolation
Subtask 22-82-00-810-062-A
A. If the test only gives the maintenance message AFS : MCDU1 (FW DISC)/FMGC1:
   (1) If the fault continues:
  • do a check and repair the wiring of the MCDU OWN FAIL discrete from the FMGC 1 (1CA1) to the first terminal block ASM 228504.
Subtask 22-82-00-810-063-A
B. If the test only gives the maintenance message AFS : MCDU 1 (FW DISC)/FMGC2:
   (1) If the fault continues:
  • do a check and repair the wiring of the MCDU OPP FAIL discrete from the FMGC 2 (1CA2) to the first terminal block ASM 228504.
Subtask 22-82-00-810-064-A
C. If the test gives the two maintenance messages AFS : MCDU1 (FW DISC)/ FMGC1 and AFS : MCDU1 (FW DISC)/FMGC2:
   (1) If the fault continues:
  • do a check and repair the wiring of the MCDU FAIL discrete from the MCDU 1 (3CA1) to the first terminal block ASM 228504.
Subtask 22-82-00-710-067-A
D. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:25:27 UTC
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