04/07/21
Message Overview:
Message Description:
Left File Server Unit (FSU) is reporting L-Radio Interface Unit (RIU)-11 bus inactive while L-RIU-11 bus is not reported inactive by the left Control Display Unit (CDU).
Possible Causes:
- Left File Server Unit (FSU 1) (A221)
- Junction Box 1 (JB1)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Radio Interface Unit (RIU) | AMM 23-51-21-000-801 |
| Installation of the Radio Interface Unit (RIU) | AMM 23-51-21-400-801 |
| Operational Test of the Radio Interface Unit (RIU) | AMM 23-51-21-710-801 |
| Junction Boxes-Component Location | AMM 24-63-00-992-802 |
| Removal of the Junction Box JB1 | AMM 24-63-01-000-802 |
| Installation of the Junction Box JB1 | AMM 24-63-01-400-802 |
| Removal of the File Server Unit (FSU) | AMM 46-21-01-000-801 |
| Installation of the File Server Unit (FSU) | AMM 46-21-01-400-801 |
| 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 FILE SERVER (CB1-C6) circuit breaker.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Do wiring check of the ARINC 429 data bus L-RIU-11 from RIU 1 connector A17P2, through Junction Box 1, to FSU 1 connector A222P1. Repair/replace as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace FSU 1.
- Do close out.