# SDR CALA2026090419240

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 3, 2026
- Submitted: September 4, 2026
- Operation: Air carrier
- Aircraft: [N37507](https://openairdocs.org/aircraft/N37507), registered now
- Make and model: Boeing 737-9
- Registry model: [Boeing 737-9](https://openairdocs.org/model/boeing-737-9) (OpenAirDocs)
- Aircraft serial: 43437
- Aircraft time: 19,911 hours, 6,622 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Fuse
- Condition: Blown
- Location: Zone 200
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026090419240

## Discrepancy

EMERGENCY LIGHTS OPS CHK,   LIGHTS INOPERATIVE ROW 1-5. PART NIS TPA ALSO NEED BATTERY AS A PRECAUTION. PART NIS TPA ALSO NEED BATTERY AS A PRECAUTION. PART NIS TPA INSTALLED MULTIPLE, VERIFIED FUNCTIONAL UNITS. NO HELP.  TROUBLESHOT EMERGENCY LIGHT SYSTEM IN REF WITH SSM 33-51-21 FOUND PICO FUSE AT POWER SUPPLY M2816 BLOWN. REPLACED FUSE AND IT BLEW AGAIN. NEED TO ISOLATE SHORT BETWEEN ROW 1-5AB FOUND PIN 2 AND PIN 5 SWPPED AT CONNECTOR D12052 AT SIDEWALL, CORRECTED PER WDM 33-51-21-4, ALSO REPLACED FUSE AT LOCATION 2 IN M1675 FOR INOP LIGHT AT G7 GALLEY PER WDM 33-51-21-4 OPS CHECK GOOD.

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