# SDR UIEA2020070901508

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 7, 2020
- Submitted: July 9, 2020
- Operation: Air carrier
- Aircraft: [N1489A](https://openairdocs.org/aircraft/N1489A), registered now
- Make and model: Boeing 767-31K
- Registry model: [Boeing 767-31K](https://openairdocs.org/model/boeing-767-31k) (OpenAirDocs)
- Aircraft serial: 27206
- Aircraft time: 107,549 hours, 21,279 cycles
- System (JASC): [2424 · AC Regulator](https://openairdocs.org/jasc/2424)
- Part: Gcu
- Part number: 734284D
- Part serial: 2044
- Condition: Failed
- Location: Left
- Stage of operation: TX
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UIEA2020070901508

## Discrepancy

LT AC BUS FAILED DURING POWER TRANSFER WHILE SHUTTING OFF ENGINES PERFORMED BITE TEST OF BPCU.  LT GCU FAIL AND BTB SW/WIRWEI GCU MESSAGES.  REMOVED AND REPLACED LT GCU PER AMM 24-22-02.  OPS CHECK GOOD.  FOUND LOOSE CONNECTOR J4 AT ELEC SYS CONTROL PANEL.  RECONNECTED CONNECTOR.  NO FURTHER DEFECTS NOTED.

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