# SDR IPXA2023022091140

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 19, 2023
- Submitted: February 20, 2023
- Operation: Air carrier
- Aircraft: [N432UP](https://openairdocs.org/aircraft/N432UP), registered now
- Make and model: Boeing 757-24APF
- Registry model: [Boeing 757-24APF](https://openairdocs.org/model/boeing-757-24apf) (OpenAirDocs)
- Aircraft serial: 25463
- Aircraft time: 29,564 hours, 20,079 cycles
- System (JASC): [2420 · AC Generation System](https://openairdocs.org/jasc/2420)
- Part: Buss
- Condition: None
- Location: Cabin
- Stage of operation: AP
- How discovered: 9
- Nature of condition: H
- Precautionary procedure: O, B
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2023022091140

## Discrepancy

DIVERSION & EMERGENCY DECLARED.  L AC BUSS OFF LIGHT IN FLIGHT. FOLLOWED PROCEEDURE IN QRH. RESETTING GEN CONT SWITCH HAD NO EFFECT. UPON STARTING APU AND RUNNING CYCLED L BUS TIE SWITCH WHICH RESTORED POWER TO ACFT. DEFERRED LEFT GENERATOR IAW MEL 24-00-1. DMP C/W. LEFT GEN DRIVE DISCONNECT ACCOMPLISHED.  TROUBLESHOT PER FIM 24-20-00-815-801, NO FAULTS NOTED ON LEFT GEN PWR SYSTEM, BUT EXTERNAL PWR SYS SHOWED: REPLACE BPCU" ON ALL FLGT LEGS. INSPECTED WING FROM LEFT ENGINE IDG TO FIREWALL, NO DEFECTS NOTED. REPL BPCU IAW MM 24-41-03. REVERSED DMP & PERFORMED ENG RUN. OPS CKS GOOD. THIS CLEARS REMOV PLAC AND UPDATED DI LOG. IPC 24-41-03-01, ITEM 10

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