# SDR ASAA2017112622713

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 26, 2017
- Submitted: November 29, 2017
- Operation: Air carrier
- Aircraft: [N407AS](https://openairdocs.org/aircraft/N407AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41731
- Aircraft time: 19,984 hours, 6,467 cycles
- System (JASC): [4940 · APU Start/Ignition System](https://openairdocs.org/jasc/4940)
- Part: Ignition Sys
- Part number: 38880587
- Part serial: 121056
- Condition: Failed
- Location: Apu
- Part time: 5,076 hours, 10,260 cycles
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2017112622713

## Discrepancy

FAULT LIGHT ILLUMINATED WHEN ATTEMPTING TO START APU. ACFT GROUNDED.  INTERROGATED APU CDU, FOUND FAULT 49-41181, IAW FIM TASK 49-40 TASK 805.  REMOVED AND REPLACED THE IGNITION UNIT IAW AMM 49-41-31.  APU STARTED, NO CURRENT FAULTS IN CDU.

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