03/23/21
Message Overview:
Message Description:
Left MFD data bus (L-MFD-1) is reported absent by the left IOC, while the right IOC does not report absence of the left IOC.
Possible Causes:
- Adaptive Flight-Display Unit (L MFD) (A29)
- Left Input/Output Concentrator Unit (IOC 1) (A4-IOC1)
- Integrated-Avionics Processor System (IAPS) Card Cage (ICC) (A4)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-000-801 |
| Installation of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-400-801 |
| Removal of the Input/Output Concentrator Unit (IOC) | AMM 31-45-05-000-801 |
| Installation of the Input/Output Concentrator Unit (IOC) | AMM 31-45-05-400-801 |
| 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 Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Reset L MFD Circuit Breaker CB1-C5 and L IAPS Circuit Breaker CB1-B6. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Swap L MFD (A29) with R MFD (A28). Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Swap L IOC with R IOC. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Do wiring check from L MFD (A29) to the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) for the following wire:
From: To: Result: Conn. A29P1 - 61 Conn. A4P1 - 65 Conn. A29P1 - 73 Conn. A4P1 - 66 - If the check is satisfactory, replace the Integrated-Avionics Processor System (IAPS) Card Cage (ICC).
- If the check is not satisfactory, repair wiring.
- Do close out.