03/24/21
Message Overview:
Message Description:
Left FMC data bus (L-FMC-6) is reported absent by the right MFD, while it is not reported absent by the right PFD, and the left IOC have received the right PFD data.
Possible Causes:
- Adaptive Flight-Display Unit 'A429 Input' (R MFD) (A28)
- Junction Box 2 (JB2)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Junction Box JB2 | AMM 24-63-05-000-803 |
| Installation of the Junction Box JB2 | AMM 24-63-05-400-803 |
| Removal of the Adaptive Flight-Display Unit | AMM 31-61-01-000-801 |
| Installation of the Adaptive Flight-Display Unit | AMM 31-61-01-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practices - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Reset R MFD Circuit Breaker CB2-C5. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Interchange R MFD (A28) with R PFD (A26). Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Do wiring check between R MFD (A28), through JB2, and R PFD (A26) for the following wires:
From: To: Result: Conn. A28P1 - 35 Conn. A26P1 - 35 Conn. A28P1 - 36 Conn. A26P1 - 36 - If the check is not satisfactory, repair defective wiring or replace defective JB2.
- If the check is satisfactory, continue with next step.
- Do close out.