# SDR CALA2020032000641

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 13, 2020
- Submitted: March 20, 2020
- Operation: Air carrier
- Aircraft: [N2748U](https://openairdocs.org/aircraft/N2748U), registered now
- Make and model: Boeing 777-300ER
- Registry model: [Boeing 777-300ER](https://openairdocs.org/model/boeing-777-300er) (OpenAirDocs)
- Aircraft serial: 64994
- Aircraft time: 6,083 hours, 533 cycles
- System (JASC): [2424 · AC Regulator](https://openairdocs.org/jasc/2424)
- Part: Gcu
- Part number: 756603F
- Condition: Faulty
- Location: Right
- Stage of operation: CL
- 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/CALA2020032000641

## Discrepancy

MOMENTARY LOSS OF ALL ELECTRICAL COMPONENTS PWR CYCLED TWICE SUSPECT GCU 2, REF FIM 24-13-00-810-809, SN5170 HAS FAULT HISTOR Y. REF TROUBLESHOOTING ON LOG PAGE 4726610, REMOVED AND REPLACED RIGHT GCU PER AMM 24-22-02-401. RAN #2 ENGINE ISOLATED AND POWERING BOTH BUSES UNDER VARIOUS LOADS. NO DEFECTS NOTED. VOLTS AND FREQS NORMAL. ROTABLE PARTS CHANGE WAS INDICATED - TT # 1336301  SN OFF 5170 UNIT, GENERATOR  OFF 23-2422-9-0001 5170 ON 23-2422-9-0001 4835

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