02/18/21
Message Overview:
Message Description:
L-CDU-6 data absent at L-HF and NOT at least 3-of (L-IOC, L-NAV, L-VHF).
Possible Causes:
- Left HF Transceiver (HF 1) (A61)
- Junction Box 3 (JB3)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick links:
| Removal of the HF Transceiver | AMM 23-12-01-000-801 |
| Installation of HF Transceiver | AMM 23-12-01-400-801 |
| 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 Control Display Unit (CDU) | AMM 34-61-05-000-801 |
| Installation of the Control Display Unit (CDU) | AMM 34-61-05-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Repair Wiring | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset HF 1 (CB1-B3) and HF 1 PWR (CB5-A1) circuit breaker.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Do the wiring check of the ARINC 429 databus L-CDU-6 from Left CDU connector A69P1, through Junction Box 3, to the HF 1 connector A61P1. Repair/replace as required.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Swap HFs.
- Do close out.